diff --git a/gerrit-common/BUCK b/gerrit-common/BUCK
index 88e503e93b..484136a7b2 100644
--- a/gerrit-common/BUCK
+++ b/gerrit-common/BUCK
@@ -51,6 +51,7 @@ java_library(
     '//lib:guava',
     '//lib/jgit:jgit',
     '//lib/joda:joda-time',
+    '//lib/log:api',
   ],
   visibility = ['PUBLIC'],
 )
diff --git a/gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java b/gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java
index c45d9f9f64..9a306968cb 100644
--- a/gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java
+++ b/gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java
@@ -16,7 +16,6 @@ package com.google.gerrit.common;
 
 import com.google.common.collect.Sets;
 
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -25,6 +24,7 @@ import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Set;
 
@@ -53,7 +53,7 @@ public final class IoUtil {
     }.start();
   }
 
-  public static void loadJARs(File... jars) {
+  public static void loadJARs(Iterable<Path> jars) {
     ClassLoader cl = IoUtil.class.getClassLoader();
     if (!(cl instanceof URLClassLoader)) {
       throw noAddURL("Not loaded by URLClassLoader", null);
@@ -71,9 +71,9 @@ public final class IoUtil {
     }
 
     Set<URL> have = Sets.newHashSet(Arrays.asList(urlClassLoader.getURLs()));
-    for (File path : jars) {
+    for (Path path : jars) {
       try {
-        URL url = path.toURI().toURL();
+        URL url = path.toUri().toURL();
         if (have.add(url)) {
           addURL.invoke(cl, url);
         }
@@ -86,6 +86,10 @@ public final class IoUtil {
     }
   }
 
+  public static void loadJARs(Path... jars) {
+    loadJARs(Arrays.asList(jars));
+  }
+
   private static UnsupportedOperationException noAddURL(String m, Throwable why) {
     String prefix = "Cannot extend classpath: ";
     return new UnsupportedOperationException(prefix + m, why);
diff --git a/gerrit-common/src/main/java/com/google/gerrit/common/SiteLibraryLoaderUtil.java b/gerrit-common/src/main/java/com/google/gerrit/common/SiteLibraryLoaderUtil.java
index a98e0a58ea..9309b18940 100644
--- a/gerrit-common/src/main/java/com/google/gerrit/common/SiteLibraryLoaderUtil.java
+++ b/gerrit-common/src/main/java/com/google/gerrit/common/SiteLibraryLoaderUtil.java
@@ -14,41 +14,59 @@
 
 package com.google.gerrit.common;
 
-import java.io.File;
-import java.io.FileFilter;
-import java.util.Arrays;
-import java.util.Comparator;
+import com.google.common.collect.ComparisonChain;
+import com.google.common.collect.Ordering;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
 
 public final class SiteLibraryLoaderUtil {
+  private static final Logger log =
+      LoggerFactory.getLogger(SiteLibraryLoaderUtil.class);
 
-  public static void loadSiteLib(File libdir) {
-    File[] jars = listJars(libdir);
-    if (jars != null && 0 < jars.length) {
-      Arrays.sort(jars, new Comparator<File>() {
-        @Override
-        public int compare(File a, File b) {
-          // Sort by reverse last-modified time so newer JARs are first.
-          int cmp = Long.compare(b.lastModified(), a.lastModified());
-          if (cmp != 0) {
-            return cmp;
-          }
-          return a.getName().compareTo(b.getName());
-        }
-      });
-      IoUtil.loadJARs(jars);
+  public static void loadSiteLib(Path libdir) {
+    try {
+      IoUtil.loadJARs(listJars(libdir));
+    } catch (IOException e) {
+      log.error("Error scanning lib directory " + libdir, e);
     }
   }
 
-  public static File[] listJars(File libdir) {
-    File[] jars = libdir.listFiles(new FileFilter() {
+  private static long lastModified(Path p) {
+    try {
+      return Files.getLastModifiedTime(p).toMillis();
+    } catch (IOException e) {
+      return 0;
+    }
+  }
+
+  public static List<Path> listJars(Path dir) throws IOException {
+    DirectoryStream.Filter<Path> filter = new DirectoryStream.Filter<Path>() {
       @Override
-      public boolean accept(File path) {
-        String name = path.getName();
-        return (name.endsWith(".jar") || name.endsWith(".zip"))
-            && path.isFile();
+      public boolean accept(Path entry) throws IOException {
+          String name = entry.getFileName().toString();
+          return (name.endsWith(".jar") || name.endsWith(".zip"))
+              && Files.isRegularFile(entry);
       }
-    });
-    return jars;
+    };
+    try (DirectoryStream<Path> jars = Files.newDirectoryStream(dir, filter)) {
+      return new Ordering<Path>() {
+        @Override
+        public int compare(Path a, Path b) {
+          // Sort by reverse last-modified time so newer JARs are first.
+          return ComparisonChain.start()
+              .compare(lastModified(b), lastModified(a))
+              .compare(a, b)
+              .result();
+        }
+      }.sortedCopy(jars);
+    }
   }
 
   private SiteLibraryLoaderUtil() {
diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
index 31ff107879..b617384273 100644
--- a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
@@ -24,6 +24,7 @@ import com.google.common.base.Strings;
 import com.google.common.cache.Cache;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.io.ByteStreams;
 import com.google.common.net.HttpHeaders;
 import com.google.gerrit.extensions.registration.RegistrationHandle;
 import com.google.gerrit.httpd.resources.Resource;
@@ -55,14 +56,14 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.List;
@@ -303,7 +304,8 @@ class HttpPluginServlet extends HttpServlet
       }
       if (!entry.isPresent() && file.endsWith("/index.html")) {
         String pfx = file.substring(0, file.length() - "index.html".length());
-        long pluginLastModified = holder.plugin.getSrcFile().lastModified();
+        long pluginLastModified =
+            Files.getLastModifiedTime(holder.plugin.getSrcFile()).toMillis();
         if (hasUpToDateCachedResource(rsc, pluginLastModified)) {
           rsc.send(req, res);
         } else {
@@ -608,12 +610,12 @@ class HttpPluginServlet extends HttpServlet
 
   private void sendJsPlugin(Plugin plugin, PluginResourceKey key,
       HttpServletRequest req, HttpServletResponse res) throws IOException {
-    File pluginFile = plugin.getSrcFile();
+    Path path = plugin.getSrcFile();
     if (req.getRequestURI().endsWith(getJsPluginPath(plugin))
-        && pluginFile.exists()) {
-      res.setHeader("Content-Length", Long.toString(pluginFile.length()));
+        && Files.exists(path)) {
+      res.setHeader("Content-Length", Long.toString(Files.size(path)));
       res.setContentType("application/javascript");
-      writeToResponse(res, new FileInputStream(pluginFile));
+      writeToResponse(res, Files.newInputStream(path));
     } else {
       resourceCache.put(key, Resource.NOT_FOUND);
       Resource.NOT_FOUND.send(req, res);
@@ -621,25 +623,15 @@ class HttpPluginServlet extends HttpServlet
   }
 
   private static String getJsPluginPath(Plugin plugin) {
-    return String.format("/plugins/%s/static/%s", plugin.getName(), plugin.getSrcFile()
-        .getName());
+    return String.format("/plugins/%s/static/%s", plugin.getName(),
+        plugin.getSrcFile().getFileName());
   }
 
-  private void writeToResponse(HttpServletResponse res, InputStream in)
+  private void writeToResponse(HttpServletResponse res, InputStream inputStream)
       throws IOException {
-    try {
-      OutputStream out = res.getOutputStream();
-      try {
-        byte[] tmp = new byte[1024];
-        int n;
-        while ((n = in.read(tmp)) > 0) {
-          out.write(tmp, 0, n);
-        }
-      } finally {
-        out.close();
-      }
-    } finally {
-      in.close();
+    try (OutputStream out = res.getOutputStream();
+        InputStream in = inputStream) {
+      ByteStreams.copy(in, out);
     }
   }
 
@@ -671,9 +663,9 @@ class HttpPluginServlet extends HttpServlet
     }
 
     private static String getPrefix(Plugin plugin, String attr, String def) {
-      File srcFile = plugin.getSrcFile();
+      Path path = plugin.getSrcFile();
       PluginContentScanner scanner = plugin.getContentScanner();
-      if (srcFile == null || scanner == PluginContentScanner.EMPTY) {
+      if (path == null || scanner == PluginContentScanner.EMPTY) {
         return def;
       }
       try {
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/SwitchSecureStore.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/SwitchSecureStore.java
index 90322d5d98..ac84e827fe 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/SwitchSecureStore.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/SwitchSecureStore.java
@@ -19,7 +19,6 @@ import static com.google.gerrit.server.schema.DataSourceProvider.Context.SINGLE_
 import com.google.common.base.Joiner;
 import com.google.common.base.Strings;
 import com.google.common.collect.Iterables;
-import com.google.common.io.Files;
 import com.google.gerrit.common.IoUtil;
 import com.google.gerrit.common.SiteLibraryLoaderUtil;
 import com.google.gerrit.pgm.util.SiteProgram;
@@ -37,8 +36,10 @@ import org.kohsuke.args4j.Option;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.List;
 import java.util.jar.JarFile;
@@ -67,14 +68,14 @@ public class SwitchSecureStore extends SiteProgram {
   @Override
   public int run() throws Exception {
     SitePaths sitePaths = new SitePaths(getSitePath());
-    File newSecureStoreFile = new File(newSecureStoreLib);
-    if (!newSecureStoreFile.exists()) {
-      log.error(String.format("File %s doesn't exists",
-          newSecureStoreFile.getAbsolutePath()));
+    Path newSecureStorePath = Paths.get(newSecureStoreLib);
+    if (!Files.exists(newSecureStorePath)) {
+      log.error(String.format("File %s doesn't exist",
+          newSecureStorePath.toAbsolutePath()));
       return -1;
     }
 
-    String newSecureStore = getNewSecureStoreClassName(newSecureStoreFile);
+    String newSecureStore = getNewSecureStoreClassName(newSecureStorePath);
     String currentSecureStoreName = getCurrentSecureStoreClassName(sitePaths);
 
     if (currentSecureStoreName.equals(newSecureStore)) {
@@ -83,7 +84,7 @@ public class SwitchSecureStore extends SiteProgram {
       return -1;
     }
 
-    IoUtil.loadJARs(newSecureStoreFile);
+    IoUtil.loadJARs(newSecureStorePath);
     SiteLibraryLoaderUtil.loadSiteLib(sitePaths.lib_dir);
 
     log.info("Current secureStoreClass property ({}) will be replaced with {}",
@@ -96,7 +97,7 @@ public class SwitchSecureStore extends SiteProgram {
     migrateProperties(currentStore, newStore);
 
     removeOldLib(sitePaths, currentSecureStoreName);
-    copyNewLib(sitePaths, newSecureStoreFile);
+    copyNewLib(sitePaths, newSecureStorePath);
 
     updateGerritConfig(sitePaths, newSecureStore);
 
@@ -123,14 +124,17 @@ public class SwitchSecureStore extends SiteProgram {
     }
   }
 
-  private void removeOldLib(SitePaths sitePaths, String currentSecureStoreName) {
-    File oldSecureStore =
+  private void removeOldLib(SitePaths sitePaths, String currentSecureStoreName)
+      throws IOException {
+    Path oldSecureStore =
         findJarWithSecureStore(sitePaths, currentSecureStoreName);
     if (oldSecureStore != null) {
       log.info("Removing old SecureStore ({}) from lib/ directory",
-          oldSecureStore.getName());
-      if (!oldSecureStore.delete()) {
-        log.error("Cannot remove {}", oldSecureStore.getAbsolutePath());
+          oldSecureStore.getFileName());
+      try {
+        Files.delete(oldSecureStore);
+      } catch (IOException e) {
+        log.error("Cannot remove {}", oldSecureStore.toAbsolutePath(), e);
       }
     } else {
       log.info("Cannot find jar with old SecureStore ({}) in lib/ directory",
@@ -138,12 +142,12 @@ public class SwitchSecureStore extends SiteProgram {
     }
   }
 
-  private void copyNewLib(SitePaths sitePaths, File newSecureStoreFile)
+  private void copyNewLib(SitePaths sitePaths, Path newSecureStorePath)
       throws IOException {
     log.info("Copy new SecureStore ({}) into lib/ directory",
-        newSecureStoreFile.getName());
-    Files.copy(newSecureStoreFile, new File(sitePaths.lib_dir,
-        newSecureStoreFile.getName()));
+        newSecureStorePath.getFileName());
+    Files.copy(newSecureStorePath,
+        sitePaths.lib_dir.resolve(newSecureStorePath.getFileName()));
   }
 
   private void updateGerritConfig(SitePaths sitePaths, String newSecureStore)
@@ -157,7 +161,7 @@ public class SwitchSecureStore extends SiteProgram {
     config.save();
   }
 
-  private String getNewSecureStoreClassName(File secureStore)
+  private String getNewSecureStoreClassName(Path secureStore)
       throws IOException {
     JarScanner scanner = new JarScanner(secureStore);
     List<String> newSecureStores =
@@ -165,12 +169,12 @@ public class SwitchSecureStore extends SiteProgram {
     if (newSecureStores.isEmpty()) {
       throw new RuntimeException(String.format(
           "Cannot find implementation of SecureStore interface in %s",
-          secureStore.getAbsolutePath()));
+          secureStore.toAbsolutePath()));
     }
     if (newSecureStores.size() > 1) {
       throw new RuntimeException(String.format(
           "Found too many implementations of SecureStore:\n%s\nin %s", Joiner
-              .on("\n").join(newSecureStores), secureStore.getAbsolutePath()));
+              .on("\n").join(newSecureStores), secureStore.toAbsolutePath()));
     }
     return Iterables.getOnlyElement(newSecureStores);
   }
@@ -195,15 +199,12 @@ public class SwitchSecureStore extends SiteProgram {
     }
   }
 
-  private File findJarWithSecureStore(SitePaths sitePaths,
-      String secureStoreClass) {
-    File[] jars = SiteLibraryLoaderUtil.listJars(sitePaths.lib_dir);
-    if (jars == null || jars.length == 0) {
-      return null;
-    }
+  private Path findJarWithSecureStore(SitePaths sitePaths,
+      String secureStoreClass) throws IOException {
+    List<Path> jars = SiteLibraryLoaderUtil.listJars(sitePaths.lib_dir);
     String secureStoreClassPath = secureStoreClass.replace('.', '/') + ".class";
-    for (File jar : jars) {
-      try (JarFile jarFile = new JarFile(jar)) {
+    for (Path jar : jars) {
+      try (JarFile jarFile = new JarFile(jar.toFile())) {
         ZipEntry entry = jarFile.getEntry(secureStoreClassPath);
         if (entry != null) {
           return jar;
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/BaseInit.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/BaseInit.java
index 7b10135baf..534ef0508f 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/BaseInit.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/BaseInit.java
@@ -56,12 +56,12 @@ import com.google.inject.util.Providers;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
@@ -292,8 +292,8 @@ public class BaseInit extends SiteProgram {
     }
 
     try {
-      File secureStoreLib = new File(secureStore);
-      if (!secureStoreLib.exists()) {
+      Path secureStoreLib = Paths.get(secureStore);
+      if (!Files.exists(secureStoreLib)) {
         throw new InvalidSecureStoreException(String.format(
             "File %s doesn't exist", secureStore));
       }
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/LibraryDownloader.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/LibraryDownloader.java
index 4bf1c886d7..5863d482a3 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/LibraryDownloader.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/LibraryDownloader.java
@@ -15,21 +15,19 @@
 package com.google.gerrit.pgm.init;
 
 import com.google.common.base.Strings;
-import com.google.common.io.Files;
+import com.google.common.hash.Funnels;
+import com.google.common.hash.Hasher;
+import com.google.common.hash.Hashing;
+import com.google.common.io.ByteStreams;
 import com.google.gerrit.common.Die;
 import com.google.gerrit.common.IoUtil;
 import com.google.gerrit.pgm.init.api.ConsoleUI;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.inject.Inject;
 
-import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.util.HttpSupport;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -38,15 +36,17 @@ import java.net.Proxy;
 import java.net.ProxySelector;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 
 /** Get optional or required 3rd party library files into $site_path/lib. */
 class LibraryDownloader {
   private final ConsoleUI ui;
-  private final File lib_dir;
+  private final Path lib_dir;
 
   private boolean required;
   private String name;
@@ -55,7 +55,7 @@ class LibraryDownloader {
   private String remove;
   private List<LibraryDownloader> needs;
   private LibraryDownloader neededBy;
-  private File dst;
+  private Path dst;
   private boolean download; // download or copy
   private boolean exists;
 
@@ -118,8 +118,8 @@ class LibraryDownloader {
       name = jarName;
     }
 
-    dst = new File(lib_dir, jarName);
-    if (dst.exists()) {
+    dst = lib_dir.resolve(jarName);
+    if (Files.exists(dst)) {
       exists = true;
     } else if (shouldGet()) {
       doGet();
@@ -158,8 +158,12 @@ class LibraryDownloader {
   }
 
   private void doGet() {
-    if (!lib_dir.exists() && !lib_dir.mkdirs()) {
-      throw new Die("Cannot create " + lib_dir);
+    if (!Files.exists(lib_dir)) {
+      try {
+        Files.createDirectories(lib_dir);
+      } catch (IOException e) {
+        throw new Die("Cannot create " + lib_dir, e);
+      }
     }
 
     try {
@@ -171,7 +175,11 @@ class LibraryDownloader {
       }
       verifyFileChecksum();
     } catch (IOException err) {
-      dst.delete();
+      try {
+        Files.delete(dst);
+      } catch (IOException e) {
+        // Delete failed; leave alone.
+      }
 
       if (ui.isBatch()) {
         throw new Die("error: Cannot get " + jarUrl, err);
@@ -186,13 +194,13 @@ class LibraryDownloader {
       System.err.println();
       System.err.println("and save as:");
       System.err.println();
-      System.err.println("  " + dst.getAbsolutePath());
+      System.err.println("  " + dst.toAbsolutePath());
       System.err.println();
       System.err.flush();
 
       ui.waitForUser();
 
-      if (dst.exists()) {
+      if (Files.exists(dst)) {
         verifyFileChecksum();
 
       } else if (!ui.yesno(!required, "Continue without this library")) {
@@ -200,7 +208,7 @@ class LibraryDownloader {
       }
     }
 
-    if (dst.exists()) {
+    if (Files.exists(dst)) {
       exists = true;
       IoUtil.loadJARs(dst);
     }
@@ -208,19 +216,27 @@ class LibraryDownloader {
 
   private void removeStaleVersions() {
     if (!Strings.isNullOrEmpty(remove)) {
-      String[] names = lib_dir.list(new FilenameFilter() {
-        @Override
-        public boolean accept(File dir, String name) {
-          return name.matches("^" + remove + "$");
-        }
-      });
-      if (names != null) {
-        for (String old : names) {
-          String bak = "." + old + ".backup";
-          ui.message("Renaming %s to %s", old, bak);
-          if (!new File(lib_dir, old).renameTo(new File(lib_dir, bak))) {
-            throw new Die("cannot rename " + old);
-          }
+      Iterable<Path> paths;
+      try {
+        paths = Files.newDirectoryStream(lib_dir,
+            new DirectoryStream.Filter<Path>() {
+              @Override
+              public boolean accept(Path entry) {
+                return entry.getFileName().toString()
+                    .matches("^" + remove + "$");
+              }
+            });
+      } catch (IOException e) {
+        throw new Die("cannot remove stale library versions", e);
+      }
+      for (Path p : paths) {
+        String old = p.getFileName().toString();
+        String bak = "." + old + ".backup";
+        ui.message("Renaming %s to %s", old, bak);
+        try {
+          Files.move(p, p.resolveSibling(bak));
+        } catch (IOException e) {
+          throw new Die("cannot rename " + old, e);
         }
       }
     }
@@ -228,111 +244,93 @@ class LibraryDownloader {
 
   private void doGetByLocalCopy() throws IOException {
     System.err.print("Copying " + jarUrl + " ...");
-    File f = url2file(jarUrl);
-    if (!f.exists()) {
+    Path p = url2file(jarUrl);
+    if (!Files.exists(p)) {
       StringBuilder msg = new StringBuilder()
           .append("\n")
           .append("Can not find the %s at this location: %s\n")
           .append("Please provide alternative URL");
-      f = url2file(ui.readString(null, msg.toString(), name, jarUrl));
+      p = url2file(ui.readString(null, msg.toString(), name, jarUrl));
     }
-    Files.copy(f, dst);
+    Files.copy(p, dst);
   }
 
-  private static File url2file(final String urlString) throws IOException {
+  private static Path url2file(final String urlString) throws IOException {
     final URL url = new URL(urlString);
     try {
-      return new File(url.toURI());
+      return Paths.get(url.toURI());
     } catch (URISyntaxException e) {
-      return new File(url.getPath());
+      return Paths.get(url.getPath());
     }
   }
 
   private void doGetByHttp() throws IOException {
     System.err.print("Downloading " + jarUrl + " ...");
     System.err.flush();
-    try {
-      final ProxySelector proxySelector = ProxySelector.getDefault();
-      final URL url = new URL(jarUrl);
-      final Proxy proxy = HttpSupport.proxyFor(proxySelector, url);
-      final HttpURLConnection c = (HttpURLConnection) url.openConnection(proxy);
-      final InputStream in;
-
-      switch (HttpSupport.response(c)) {
-        case HttpURLConnection.HTTP_OK:
-          in = c.getInputStream();
-          break;
-
-        case HttpURLConnection.HTTP_NOT_FOUND:
-          throw new FileNotFoundException(url.toString());
-
-        default:
-          throw new IOException(url.toString() + ": " + HttpSupport.response(c)
-              + " " + c.getResponseMessage());
-      }
-
-      try {
-        final OutputStream out = new FileOutputStream(dst);
-        try {
-          final byte[] buf = new byte[8192];
-          int n;
-          while ((n = in.read(buf)) > 0) {
-            out.write(buf, 0, n);
-          }
-        } finally {
-          out.close();
-        }
-      } finally {
-        in.close();
-      }
+    try (InputStream in = openHttpStream(jarUrl);
+        OutputStream out = Files.newOutputStream(dst)) {
+      ByteStreams.copy(in, out);
       System.err.println(" OK");
       System.err.flush();
     } catch (IOException err) {
-      dst.delete();
+      deleteDst();
       System.err.println(" !! FAIL !!");
       System.err.flush();
       throw err;
     }
   }
 
+  private static InputStream openHttpStream(String urlStr) throws IOException {
+    ProxySelector proxySelector = ProxySelector.getDefault();
+    URL url = new URL(urlStr);
+    Proxy proxy = HttpSupport.proxyFor(proxySelector, url);
+    HttpURLConnection c = (HttpURLConnection) url.openConnection(proxy);
+
+    switch (HttpSupport.response(c)) {
+      case HttpURLConnection.HTTP_OK:
+        return c.getInputStream();
+
+      case HttpURLConnection.HTTP_NOT_FOUND:
+        throw new FileNotFoundException(url.toString());
+
+      default:
+        throw new IOException(url.toString() + ": " + HttpSupport.response(c)
+            + " " + c.getResponseMessage());
+    }
+  }
+
   private void verifyFileChecksum() {
-    if (sha1 != null) {
-      try {
-        final MessageDigest md = MessageDigest.getInstance("SHA-1");
-        final FileInputStream in = new FileInputStream(dst);
-        try {
-          final byte[] buf = new byte[8192];
-          int n;
-          while ((n = in.read(buf)) > 0) {
-            md.update(buf, 0, n);
-          }
-        } finally {
-          in.close();
-        }
+    if (sha1 == null) {
+      return;
+    }
+    Hasher h = Hashing.sha1().newHasher();
+    try (InputStream in = Files.newInputStream(dst);
+        OutputStream out = Funnels.asOutputStream(h)) {
+      ByteStreams.copy(in, out);
+    } catch (IOException e) {
+      deleteDst();
+      throw new Die("cannot checksum " + dst, e);
+    }
+    if (sha1.equals(h.hash().toString())) {
+      System.err.println("Checksum " + dst.getFileName() + " OK");
+      System.err.flush();
+    } else if (ui.isBatch()) {
+      deleteDst();
+      throw new Die(dst + " SHA-1 checksum does not match");
 
-        if (sha1.equals(ObjectId.fromRaw(md.digest()).name())) {
-          System.err.println("Checksum " + dst.getName() + " OK");
-          System.err.flush();
+    } else if (!ui.yesno(null /* force an answer */,
+        "error: SHA-1 checksum does not match\n" + "Use %s anyway",//
+        dst.getFileName())) {
+      deleteDst();
+      throw new Die("aborted by user");
+    }
+  }
 
-        } else if (ui.isBatch()) {
-          dst.delete();
-          throw new Die(dst + " SHA-1 checksum does not match");
-
-        } else if (!ui.yesno(null /* force an answer */,
-            "error: SHA-1 checksum does not match\n" + "Use %s anyway",//
-            dst.getName())) {
-          dst.delete();
-          throw new Die("aborted by user");
-        }
-
-      } catch (IOException checksumError) {
-        dst.delete();
-        throw new Die("cannot checksum " + dst, checksumError);
-
-      } catch (NoSuchAlgorithmException checksumError) {
-        dst.delete();
-        throw new Die("cannot checksum " + dst, checksumError);
-      }
+  private void deleteDst() {
+    try {
+      Files.delete(dst);
+    } catch (IOException e) {
+      System.err.println(" Failed to clean up lib: " + dst);
     }
   }
 }
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SecureStoreInitData.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SecureStoreInitData.java
index 8926759d90..49877dc8d3 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SecureStoreInitData.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SecureStoreInitData.java
@@ -14,13 +14,13 @@
 
 package com.google.gerrit.pgm.init;
 
-import java.io.File;
+import java.nio.file.Path;
 
 class SecureStoreInitData {
-  final File jarFile;
+  final Path jarFile;
   final String className;
 
-  SecureStoreInitData(File jar, String className) {
+  SecureStoreInitData(Path jar, String className) {
     this.className = className;
     this.jarFile = jar;
   }
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SitePathInitializer.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SitePathInitializer.java
index d4cf24c730..f8678292ca 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SitePathInitializer.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/SitePathInitializer.java
@@ -21,7 +21,6 @@ import static com.google.gerrit.pgm.init.api.InitUtil.mkdir;
 import static com.google.gerrit.pgm.init.api.InitUtil.savePublic;
 import static com.google.gerrit.pgm.init.api.InitUtil.version;
 
-import com.google.common.io.Files;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.pgm.init.api.ConsoleUI;
 import com.google.gerrit.pgm.init.api.InitFlags;
@@ -37,6 +36,8 @@ import com.google.inject.TypeLiteral;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -132,7 +133,8 @@ public class SitePathInitializer {
 
   private void saveSecureStore() throws IOException {
     if (secureStoreInitData != null) {
-      File dst = new File(site.lib_dir, secureStoreInitData.jarFile.getName());
+      Path dst =
+          site.lib_dir.resolve(secureStoreInitData.jarFile.getFileName());
       Files.copy(secureStoreInitData.jarFile, dst);
       Section gerritSection = sectionFactory.get("gerrit", null);
       gerritSection.set("secureStoreClass", secureStoreInitData.className);
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/util/SiteLibraryBasedDataSourceProvider.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/util/SiteLibraryBasedDataSourceProvider.java
index c713b79869..048c2eed12 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/util/SiteLibraryBasedDataSourceProvider.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/util/SiteLibraryBasedDataSourceProvider.java
@@ -24,14 +24,14 @@ import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.Config;
 
-import java.io.File;
+import java.nio.file.Path;
 
 import javax.sql.DataSource;
 
 /** Loads the site library if not yet loaded. */
 @Singleton
 public class SiteLibraryBasedDataSourceProvider extends DataSourceProvider {
-  private final File libdir;
+  private final Path libdir;
   private boolean init;
 
   @Inject
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/config/SitePaths.java b/gerrit-server/src/main/java/com/google/gerrit/server/config/SitePaths.java
index b5ff22ff2c..a3e7924834 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/config/SitePaths.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/config/SitePaths.java
@@ -32,7 +32,7 @@ public final class SitePaths {
   public final File site_path;
   public final Path bin_dir;
   public final Path etc_dir;
-  public final File lib_dir;
+  public final Path lib_dir;
   public final Path tmp_dir;
   public final File logs_dir;
   public final File plugins_dir;
@@ -72,7 +72,7 @@ public final class SitePaths {
 
     bin_dir = p.resolve("bin");
     etc_dir = p.resolve("etc");
-    lib_dir = new File(site_path, "lib");
+    lib_dir = p.resolve("lib");
     tmp_dir = p.resolve("tmp");
     plugins_dir = new File(site_path, "plugins");
     data_dir = new File(site_path, "data");
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarPluginProvider.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarPluginProvider.java
index 5c0b41c5d6..37c05d556f 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarPluginProvider.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarPluginProvider.java
@@ -32,6 +32,7 @@ import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
@@ -85,7 +86,8 @@ public class JarPluginProvider implements ServerPluginProvider {
       String extension = getExtension(srcFile);
       try (FileInputStream in = new FileInputStream(srcFile)) {
         File tmp = asTemp(in, tempNameFor(name), extension, tmpDir);
-        return loadJarPlugin(name, srcFile, snapshot, tmp, description);
+        return loadJarPlugin(name, srcFile.toPath(), snapshot, tmp,
+            description);
       }
     } catch (IOException e) {
       throw new InvalidPluginException("Cannot load Jar plugin " + srcFile, e);
@@ -120,7 +122,7 @@ public class JarPluginProvider implements ServerPluginProvider {
         sitePaths.tmp_dir.toFile());
   }
 
-  private ServerPlugin loadJarPlugin(String name, File srcJar,
+  private ServerPlugin loadJarPlugin(String name, Path srcJar,
       FileSnapshot snapshot, File tmp, PluginDescription description)
       throws IOException, InvalidPluginException, MalformedURLException {
     JarFile jarFile = new JarFile(tmp);
@@ -146,10 +148,9 @@ public class JarPluginProvider implements ServerPluginProvider {
               PluginLoader.parentFor(type));
 
       JarScanner jarScanner = createJarScanner(srcJar);
-      ServerPlugin plugin =
-          new ServerPlugin(name, description.canonicalUrl, description.user,
-              srcJar, snapshot, jarScanner, description.dataDir,
-              pluginLoader);
+      ServerPlugin plugin = new ServerPlugin(name, description.canonicalUrl,
+          description.user, srcJar.toFile(), snapshot, jarScanner,
+          description.dataDir, pluginLoader);
       plugin.setCleanupHandle(new CleanupHandle(tmp, jarFile));
       keep = true;
       return plugin;
@@ -160,7 +161,7 @@ public class JarPluginProvider implements ServerPluginProvider {
     }
   }
 
-  private JarScanner createJarScanner(File srcJar)
+  private JarScanner createJarScanner(Path srcJar)
       throws InvalidPluginException {
     try {
       return new JarScanner(srcJar);
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarScanner.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarScanner.java
index a8600fe683..0f4aa6ce75 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarScanner.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JarScanner.java
@@ -39,10 +39,10 @@ import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.annotation.Annotation;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -69,8 +69,8 @@ public class JarScanner implements PluginContentScanner {
 
   private final JarFile jarFile;
 
-  public JarScanner(File srcFile) throws IOException {
-    this.jarFile = new JarFile(srcFile);
+  public JarScanner(Path src) throws IOException {
+    this.jarFile = new JarFile(src.toFile());
   }
 
   @Override
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JsPlugin.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JsPlugin.java
index 63f69b510e..8da8cc1efb 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JsPlugin.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/JsPlugin.java
@@ -27,12 +27,12 @@ import com.google.inject.Injector;
 
 import org.eclipse.jgit.internal.storage.file.FileSnapshot;
 
-import java.io.File;
+import java.nio.file.Path;
 
 class JsPlugin extends Plugin {
   private Injector httpInjector;
 
-  JsPlugin(String name, File srcFile, PluginUser pluginUser,
+  JsPlugin(String name, Path srcFile, PluginUser pluginUser,
       FileSnapshot snapshot) {
     super(name, srcFile, pluginUser, snapshot, ApiType.JS);
   }
@@ -40,7 +40,7 @@ class JsPlugin extends Plugin {
   @Override
   @Nullable
   public String getVersion() {
-    String fileName = getSrcFile().getName();
+    String fileName = getSrcFile().getFileName().toString();
     int firstDash = fileName.indexOf("-");
     if (firstDash > 0) {
       return fileName.substring(firstDash + 1, fileName.lastIndexOf(".js"));
@@ -51,7 +51,7 @@ class JsPlugin extends Plugin {
   @Override
   public void start(PluginGuiceEnvironment env) throws Exception {
     manager = new LifecycleManager();
-    String fileName = getSrcFile().getName();
+    String fileName = getSrcFile().getFileName().toString();
     httpInjector =
         Guice.createInjector(new StandaloneJsPluginModule(getName(), fileName));
     manager.start();
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ListPlugins.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ListPlugins.java
index 54f05f05f7..1d717efa77 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ListPlugins.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ListPlugins.java
@@ -90,7 +90,7 @@ public class ListPlugins implements RestReadView<TopLevelResource> {
         stdout.format("%-30s %-10s %-8s %s\n", p.getName(),
             Strings.nullToEmpty(info.version),
             p.isDisabled() ? "DISABLED" : "ENABLED",
-            p.getSrcFile().getName());
+            p.getSrcFile().getFileName());
       }
     }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/Plugin.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/Plugin.java
index b227909747..1be65aa335 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/Plugin.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/Plugin.java
@@ -26,6 +26,7 @@ import com.google.inject.Injector;
 import org.eclipse.jgit.internal.storage.file.FileSnapshot;
 
 import java.io.File;
+import java.nio.file.Path;
 import java.util.Collections;
 import java.util.List;
 import java.util.jar.Attributes;
@@ -67,7 +68,7 @@ public abstract class Plugin {
   }
 
   private final String name;
-  private final File srcFile;
+  private final Path srcFile;
   private final ApiType apiType;
   private final boolean disabled;
   private final CacheKey cacheKey;
@@ -80,17 +81,18 @@ public abstract class Plugin {
   private List<ReloadableRegistrationHandle<?>> reloadableHandles;
 
   public Plugin(String name,
-      File srcFile,
+      Path srcFile,
       PluginUser pluginUser,
       FileSnapshot snapshot,
       ApiType apiType) {
     this.name = name;
+    // TODO(dborowitz): Rename to srcPath or something.
     this.srcFile = srcFile;
     this.apiType = apiType;
     this.snapshot = snapshot;
     this.pluginUser = pluginUser;
     this.cacheKey = new Plugin.CacheKey(name);
-    this.disabled = srcFile.getName().endsWith(".disabled");
+    this.disabled = srcFile.getFileName().toString().endsWith(".disabled");
   }
 
   public CleanupHandle getCleanupHandle() {
@@ -105,7 +107,7 @@ public abstract class Plugin {
     return pluginUser;
   }
 
-  public File getSrcFile() {
+  public Path getSrcFile() {
     return srcFile;
   }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginLoader.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginLoader.java
index b51359df8c..3fee7d7592 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginLoader.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginLoader.java
@@ -50,6 +50,7 @@ import java.io.FileFilter;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.Path;
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -172,11 +173,11 @@ public class PluginLoader implements LifecycleListener {
     synchronized (this) {
       Plugin active = running.get(name);
       if (active != null) {
-        fileName = active.getSrcFile().getName();
+        fileName = active.getSrcFile().getFileName().toString();
         log.info(String.format("Replacing plugin %s", active.getName()));
         File old = new File(pluginsDir, ".last_" + fileName);
         old.delete();
-        active.getSrcFile().renameTo(old);
+        active.getSrcFile().toFile().renameTo(old);
       }
 
       new File(pluginsDir, fileName + ".disabled").delete();
@@ -241,7 +242,7 @@ public class PluginLoader implements LifecycleListener {
 
         log.info(String.format("Disabling plugin %s", active.getName()));
         File off = new File(active.getSrcFile() + ".disabled");
-        active.getSrcFile().renameTo(off);
+        active.getSrcFile().toFile().renameTo(off);
 
         unloadPlugin(active);
         try {
@@ -274,12 +275,12 @@ public class PluginLoader implements LifecycleListener {
         }
 
         log.info(String.format("Enabling plugin %s", name));
-        String n = off.getSrcFile().getName();
+        String n = off.getSrcFile().toFile().getName();
         if (n.endsWith(".disabled")) {
           n = n.substring(0, n.lastIndexOf('.'));
         }
         File on = new File(pluginsDir, n);
-        off.getSrcFile().renameTo(on);
+        off.getSrcFile().toFile().renameTo(on);
 
         disabled.remove(name);
         runPlugin(name, on, null);
@@ -342,7 +343,7 @@ public class PluginLoader implements LifecycleListener {
         String name = active.getName();
         try {
           log.info(String.format("Reloading plugin %s", name));
-          runPlugin(name, active.getSrcFile(), active);
+          runPlugin(name, active.getSrcFile().toFile(), active);
         } catch (PluginInstallException e) {
           log.warn(String.format("Cannot reload plugin %s", name), e.getCause());
           throw e;
@@ -549,7 +550,7 @@ public class PluginLoader implements LifecycleListener {
       throws InvalidPluginException {
     String pluginName = srcPlugin.getName();
     if (isJsPlugin(pluginName)) {
-      return loadJsPlugin(name, srcPlugin, snapshot);
+      return loadJsPlugin(name, srcPlugin.toPath(), snapshot);
     } else if (serverPluginFactory.handles(srcPlugin)) {
       return loadServerPlugin(srcPlugin, snapshot);
     } else {
@@ -569,7 +570,7 @@ public class PluginLoader implements LifecycleListener {
     return url;
   }
 
-  private Plugin loadJsPlugin(String name, File srcJar, FileSnapshot snapshot) {
+  private Plugin loadJsPlugin(String name, Path srcJar, FileSnapshot snapshot) {
     return new JsPlugin(name, srcJar, pluginUserFactory.create(name), snapshot);
   }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPlugin.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPlugin.java
index 0b037fb678..15888008a2 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPlugin.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPlugin.java
@@ -80,7 +80,8 @@ public class ServerPlugin extends Plugin {
       PluginContentScanner scanner,
       File dataDir,
       ClassLoader classLoader) throws InvalidPluginException {
-    super(name, srcJar, pluginUser, snapshot, Plugin.getApiType(getPluginManifest(scanner)));
+    super(name, srcJar.toPath(), pluginUser, snapshot,
+        Plugin.getApiType(getPluginManifest(scanner)));
     this.pluginCanonicalWebUrl = pluginCanonicalWebUrl;
     this.scanner = scanner;
     this.dataDir = dataDir;
@@ -128,7 +129,7 @@ public class ServerPlugin extends Plugin {
   }
 
   File getSrcJar() {
-    return getSrcFile();
+    return getSrcFile().toFile();
   }
 
   private static Manifest getPluginManifest(PluginContentScanner scanner)
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPluginProvider.java b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPluginProvider.java
index 37fed9b477..a529b6d814 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPluginProvider.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPluginProvider.java
@@ -31,6 +31,7 @@ import java.io.File;
  * group them into a directory tree and then load the directory
  * root as a single plugin.
  */
+// TODO(dborowitz): Convert to NIO; ensure clients can migrate.
 @ExtensionPoint
 public interface ServerPluginProvider {
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/securestore/SecureStoreProvider.java b/gerrit-server/src/main/java/com/google/gerrit/server/securestore/SecureStoreProvider.java
index e8305906f0..99127d8865 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/securestore/SecureStoreProvider.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/securestore/SecureStoreProvider.java
@@ -26,14 +26,14 @@ import com.google.inject.Singleton;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.File;
+import java.nio.file.Path;
 
 @Singleton
 public class SecureStoreProvider implements Provider<SecureStore> {
   private static final Logger log = LoggerFactory
       .getLogger(SecureStoreProvider.class);
 
-  private final File libdir;
+  private final Path libdir;
   private final Injector injector;
   private final String className;