Fix outstanding issues with conversion to NIO

NIO methods throw NoSuchFileException, not FileNotFoundException. How
nice.

Throwing from Files#getLastModifiedTime, apart from cluttering up
throws clauses, means callers have to check for FileNotFoundException,
which is verbose and error prone. Instead, implement a helper with the
old File#lastModified() semantics; this preserves old behavior, which
might not handle some error cases well, but worked well enough. (In
theory we could use FileSnapshot or something, but I don't want to
shave that particular yak until/unless I get a chance to add a
Path-compatible interface to FileSnapshot in JGit as well.)

Organize some imports.

Tested:
-Tests pass.
-Initialized a site, including downloading.
-Launched a site.
-Added and removed site headers and CSS in a running site.
-Added and removed plugins, both live and while shutdown.

Change-Id: I60dfe5280512f00dce4ec99fe3689b2f2b3c6685

gerrit-common/src/main/java/com/google/gerrit/common/FileUtil.java

@@ -68,8 +68,17 @@ public class FileUtil {
     }
   }
 
+  /**
+   * Get the last modified time of a path.
+   * <p>
+   * Equivalent to {@code File#lastModified()}, returning 0 on errors, including
+   * file not found. Callers that prefer exceptions can use {@link
+   * Files#getLastModifiedTime(Path, java.nio.file.LinkOption...)}.
+   *
+   * @param p path.
+   * @return last modified time, in milliseconds since epoch.
+   */
   public static long lastModified(Path p) {
-    // Replicate File#lastModified() behavior of returning 0 on errors.
     try {
       return Files.getLastModifiedTime(p).toMillis();
     } catch (IOException e) {

gerrit-common/src/main/java/com/google/gerrit/common/SiteLibraryLoaderUtil.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.common;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
+
 import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.Ordering;
 
@@ -38,14 +40,6 @@ public final class SiteLibraryLoaderUtil {
     }
   }
 
-  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

gerrit-httpd/src/main/java/com/google/gerrit/httpd/HtmlDomUtil.java

@@ -23,13 +23,13 @@ import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;
 
 import java.io.ByteArrayOutputStream;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.StringWriter;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.zip.GZIPOutputStream;
 
@@ -192,7 +192,7 @@ public class HtmlDomUtil {
       Document doc = newBuilder().parse(in);
       compact(doc);
       return doc;
-    } catch (FileNotFoundException e) {
+    } catch (NoSuchFileException e) {
       return null;
     } catch (SAXException | ParserConfigurationException | IOException e) {
       throw new IOException("Error reading " + path, e);
@@ -208,7 +208,7 @@ public class HtmlDomUtil {
     Path path = parentDir.resolve(name);
     try (InputStream in = Files.newInputStream(path)) {
       return new String(ByteStreams.toByteArray(in), ENC);
-    } catch (FileNotFoundException e) {
+    } catch (NoSuchFileException e) {
       return null;
     } catch (IOException e) {
       throw new IOException("Error reading " + path, e);

gerrit-httpd/src/main/java/com/google/gerrit/httpd/gitweb/GitLogoServlet.java

@@ -14,16 +14,18 @@
 
 package com.google.gerrit.httpd.gitweb;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
+
 import com.google.common.io.ByteStreams;
 import com.google.gerrit.httpd.GitWebConfig;
 import com.google.gwtexpui.server.CacheHeaders;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.concurrent.TimeUnit;
 
@@ -45,10 +47,10 @@ class GitLogoServlet extends HttpServlet {
     if (src != null) {
       try (InputStream in = Files.newInputStream(src)) {
         png = ByteStreams.toByteArray(in);
-      } catch (FileNotFoundException e) {
+      } catch (NoSuchFileException e) {
         png = null;
       }
-      modified = Files.getLastModifiedTime(src).toMillis();
+      modified = lastModified(src);
     } else {
       modified = -1;
       png = null;

gerrit-httpd/src/main/java/com/google/gerrit/httpd/gitweb/GitWebCssServlet.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.httpd.gitweb;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
+
 import com.google.gerrit.httpd.GitWebConfig;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.server.config.SitePaths;
@@ -23,7 +25,6 @@ import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
 import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.concurrent.TimeUnit;
 
@@ -63,7 +64,7 @@ abstract class GitWebCssServlet extends HttpServlet {
       final String name = src.getFileName().toString();
       final String raw = HtmlDomUtil.readFile(dir, name);
       if (raw != null) {
-        modified = Files.getLastModifiedTime(src).toMillis();
+        modified = lastModified(src);
         raw_css = raw.getBytes(ENC);
         gz_css = HtmlDomUtil.compress(raw_css);
       } else {

gerrit-httpd/src/main/java/com/google/gerrit/httpd/gitweb/GitWebJavaScriptServlet.java

@@ -14,16 +14,18 @@
 
 package com.google.gerrit.httpd.gitweb;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
+
 import com.google.common.io.ByteStreams;
 import com.google.gerrit.httpd.GitWebConfig;
 import com.google.gwtexpui.server.CacheHeaders;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.concurrent.TimeUnit;
 
@@ -45,10 +47,10 @@ class GitWebJavaScriptServlet extends HttpServlet {
     if (src != null) {
       try (InputStream in = Files.newInputStream(src)) {
         png = ByteStreams.toByteArray(in);
-      } catch (FileNotFoundException e) {
+      } catch (NoSuchFileException e) {
         png = null;
       }
-      modified = Files.getLastModifiedTime(src).toMillis();
+      modified = lastModified(src);
     } else {
       modified = -1;
       png = null;

gerrit-httpd/src/main/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java

@@ -14,6 +14,7 @@
 
 package com.google.gerrit.httpd.plugins;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
 import static com.google.gerrit.server.plugins.PluginEntry.ATTR_CHARACTER_ENCODING;
 import static com.google.gerrit.server.plugins.PluginEntry.ATTR_CONTENT_TYPE;
 
@@ -304,8 +305,7 @@ class HttpPluginServlet extends HttpServlet
       }
       if (!entry.isPresent() && file.endsWith("/index.html")) {
         String pfx = file.substring(0, file.length() - "index.html".length());
-        long pluginLastModified =
-            Files.getLastModifiedTime(holder.plugin.getSrcFile()).toMillis();
+        long pluginLastModified = lastModified(holder.plugin.getSrcFile());
         if (hasUpToDateCachedResource(rsc, pluginLastModified)) {
           rsc.send(req, res);
         } else {

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/HostPageServlet.java

@@ -14,7 +14,7 @@
 
 package com.google.gerrit.httpd.raw;
 
-import static java.nio.file.Files.getLastModifiedTime;
+import static com.google.gerrit.common.FileUtil.lastModified;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
@@ -55,7 +55,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.StringWriter;
 import java.nio.file.Path;
-import java.nio.file.attribute.FileTime;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -289,15 +288,15 @@ public class HostPageServlet extends HttpServlet {
 
   private static class FileInfo {
     private final Path path;
-    private final FileTime time;
+    private final long time;
 
-    FileInfo(Path p) throws IOException {
+    FileInfo(Path p) {
       path = p;
-      time = getLastModifiedTime(path);
+      time = lastModified(path);
     }
 
-    boolean isStale() throws IOException {
-      return !time.equals(getLastModifiedTime(path));
+    boolean isStale() {
+      return time != lastModified(path);
     }
   }
 
@@ -340,7 +339,7 @@ public class HostPageServlet extends HttpServlet {
       debug = new Content(hostDoc);
     }
 
-    boolean isStale() throws IOException {
+    boolean isStale() {
       return css.isStale() || header.isStale() || footer.isStale();
     }
 

gerrit-httpd/src/main/java/com/google/gerrit/httpd/template/SiteHeaderFooter.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.httpd.template;
 
+import static com.google.gerrit.common.FileUtil.lastModified;
+
 import com.google.common.base.Strings;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.server.config.GerritServerConfig;
@@ -28,9 +30,7 @@ import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
 import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.attribute.FileTime;
 
 @Singleton
 public class SiteHeaderFooter {
@@ -112,7 +112,7 @@ public class SiteHeaderFooter {
     Element header;
     Element footer;
 
-    Template(SitePaths site) throws IOException {
+    Template(SitePaths site) {
       cssFile = new FileInfo(site.site_css);
       headerFile = new FileInfo(site.site_header);
       footerFile = new FileInfo(site.site_footer);
@@ -126,7 +126,7 @@ public class SiteHeaderFooter {
       footer = readXml(footerFile);
     }
 
-    boolean isStale() throws IOException {
+    boolean isStale() {
       return cssFile.isStale() || headerFile.isStale() || footerFile.isStale();
     }
 
@@ -138,15 +138,15 @@ public class SiteHeaderFooter {
 
   private static class FileInfo {
     final Path path;
-    final FileTime time;
+    final long time;
 
-    FileInfo(Path p) throws IOException {
+    FileInfo(Path p) {
       path = p;
-      time = Files.getLastModifiedTime(path);
+      time = lastModified(p);
     }
 
-    boolean isStale() throws IOException {
-      return !time.equals(Files.getLastModifiedTime(path));
+    boolean isStale() {
+      return time != lastModified(path);
     }
   }
 }

gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java

@@ -15,7 +15,6 @@
 package com.google.gerrit.pgm;
 
 import static com.google.gerrit.server.schema.DataSourceProvider.Context.MULTI_USER;
-
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.annotations.VisibleForTesting;

gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/InitSshd.java

@@ -17,7 +17,6 @@ package com.google.gerrit.pgm.init;
 import static com.google.gerrit.common.FileUtil.chmod;
 import static com.google.gerrit.pgm.init.api.InitUtil.die;
 import static com.google.gerrit.pgm.init.api.InitUtil.hostname;
-
 import static java.nio.file.Files.exists;
 
 import com.google.gerrit.pgm.init.api.ConsoleUI;

gerrit-pgm/src/test/java/com/google/gerrit/pgm/init/UpgradeFrom2_0_xTest.java

@@ -15,7 +15,6 @@
 package com.google.gerrit.pgm.init;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
-
 import static org.easymock.EasyMock.createStrictMock;
 import static org.easymock.EasyMock.eq;
 import static org.easymock.EasyMock.expect;

gerrit-server/src/main/java/com/google/gerrit/server/securestore/DefaultSecureStore.java

@@ -26,8 +26,8 @@ import org.eclipse.jgit.util.FS;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.ArrayList;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.List;
 
 @Singleton

gerrit-sshd/src/main/java/com/google/gerrit/sshd/DatabasePubKeyAuth.java

@@ -36,9 +36,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.BufferedReader;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.security.KeyPair;
 import java.security.PublicKey;
@@ -203,7 +203,7 @@ class DatabasePubKeyAuth implements PublickeyAuthenticator {
           }
         }
         return Collections.unmodifiableSet(keys);
-      } catch (FileNotFoundException noFile) {
+      } catch (NoSuchFileException noFile) {
         return Collections.emptySet();
       } catch (IOException err) {
         log.error("Cannot read " + path, err);