b0fb0a7a96
Change-Id: I986a5507aa26ceb28305a7b08991e85238bde0e3
54 lines
2.2 KiB
Java
54 lines
2.2 KiB
Java
// Copyright (C) 2012 The Android Open Source Project
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package com.google.gerrit.server;
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public class StringUtil {
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/**
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* An array of the string representations that should be used in place of the non-printable
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* characters in the beginning of the ASCII table when escaping a string. The index of each
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* element in the array corresponds to its ASCII value, i.e. the string representation of ASCII 0
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* is found in the first element of this array.
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*/
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private static final String[] NON_PRINTABLE_CHARS = {
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"\\x00", "\\x01", "\\x02", "\\x03", "\\x04", "\\x05", "\\x06", "\\a",
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"\\b", "\\t", "\\n", "\\v", "\\f", "\\r", "\\x0e", "\\x0f",
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"\\x10", "\\x11", "\\x12", "\\x13", "\\x14", "\\x15", "\\x16", "\\x17",
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"\\x18", "\\x19", "\\x1a", "\\x1b", "\\x1c", "\\x1d", "\\x1e", "\\x1f",
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};
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/**
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* Escapes the input string so that all non-printable characters (0x00-0x1f) are represented as a
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* hex escape (\x00, \x01, ...) or as a C-style escape sequence (\a, \b, \t, \n, \v, \f, or \r).
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* Backslashes in the input string are doubled (\\).
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*/
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public static String escapeString(String str) {
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// Allocate a buffer big enough to cover the case with a string needed
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// very excessive escaping without having to reallocate the buffer.
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final StringBuilder result = new StringBuilder(3 * str.length());
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for (int i = 0; i < str.length(); i++) {
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char c = str.charAt(i);
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if (c < NON_PRINTABLE_CHARS.length) {
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result.append(NON_PRINTABLE_CHARS[c]);
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} else if (c == '\\') {
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result.append("\\\\");
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} else {
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result.append(c);
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}
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}
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return result.toString();
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}
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}
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