Use Streams instead of Escaper.

Fixes issue 345.

gson/src/main/java/com/google/gson/Escaper.java

@@ -1,160 +0,0 @@
-/*
- * Copyright (C) 2008 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.gson;
-
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-
-/**
- * A utility class that is used to perform JSON escaping so that ", <, >, etc. characters are
- * properly encoded in the JSON string representation before returning to the client code.
- *
- * <p>This class contains a single method to escape a passed in string value:
- * <pre>
- *   String jsonStringValue = "beforeQuote\"afterQuote";
- *   String escapedValue = Escaper.escapeJsonString(jsonStringValue);
- * </pre></p>
- *
- * @author Inderjeet Singh
- * @author Joel Leitch
- */
-final class Escaper {
-
-  private static final char[] HEX_CHARS = {
-    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
-  };
-
-  private static final Set<Character> JS_ESCAPE_CHARS;
-  private static final Set<Character> HTML_ESCAPE_CHARS;
-
-  static {
-    Set<Character> mandatoryEscapeSet = new HashSet<Character>();
-    mandatoryEscapeSet.add('"');
-    mandatoryEscapeSet.add('\\');
-    JS_ESCAPE_CHARS = Collections.unmodifiableSet(mandatoryEscapeSet);
-
-    Set<Character> htmlEscapeSet = new HashSet<Character>();
-    htmlEscapeSet.add('<');
-    htmlEscapeSet.add('>');
-    htmlEscapeSet.add('&');
-    htmlEscapeSet.add('=');
-    htmlEscapeSet.add('\'');
-//    htmlEscapeSet.add('/');  -- Removing slash for now since it causes some incompatibilities
-    HTML_ESCAPE_CHARS = Collections.unmodifiableSet(htmlEscapeSet);
-  }
-
-  private final boolean escapeHtmlCharacters;
-
-  Escaper(boolean escapeHtmlCharacters) {
-    this.escapeHtmlCharacters = escapeHtmlCharacters;
-  }
-
-  public String escapeJsonString(CharSequence plainText) {
-    StringBuilder escapedString = new StringBuilder(plainText.length() + 20);
-    try {
-      escapeJsonString(plainText, escapedString);
-    } catch (IOException e) {
-      throw new RuntimeException(e);
-    }
-    return escapedString.toString();
-  }
-
-  private void escapeJsonString(CharSequence plainText, StringBuilder out) throws IOException {
-    int pos = 0;  // Index just past the last char in plainText written to out.
-    int len = plainText.length();
-
-    for (int charCount, i = 0; i < len; i += charCount) {
-      int codePoint = Character.codePointAt(plainText, i);
-      charCount = Character.charCount(codePoint);
-
-       if (!isControlCharacter(codePoint) && !mustEscapeCharInJsString(codePoint)) {
-          continue;
-       }
-
-       out.append(plainText, pos, i);
-       pos = i + charCount;
-       switch (codePoint) {
-         case '\b':
-           out.append("\\b");
-           break;
-         case '\t':
-           out.append("\\t");
-           break;
-         case '\n':
-           out.append("\\n");
-           break;
-         case '\f':
-           out.append("\\f");
-           break;
-         case '\r':
-           out.append("\\r");
-           break;
-         case '\\':
-           out.append("\\\\");
-           break;
-         case '/':
-           out.append("\\/");
-           break;
-         case '"':
-           out.append("\\\"");
-           break;
-         default:
-           appendHexJavaScriptRepresentation(codePoint, out);
-           break;
-       }
-     }
-     out.append(plainText, pos, len);
-  }
-
-  private boolean mustEscapeCharInJsString(int codepoint) {
-    if (!Character.isSupplementaryCodePoint(codepoint)) {
-      char c = (char) codepoint;
-      return JS_ESCAPE_CHARS.contains(c)
-          || (escapeHtmlCharacters && HTML_ESCAPE_CHARS.contains(c));
-    }
-    return false;
-  }
-
-  private static boolean isControlCharacter(int codePoint) {
-    // JSON spec defines these code points as control characters, so they must be escaped
-    return codePoint < 0x20
-        || codePoint == 0x2028  // Line separator
-        || codePoint == 0x2029  // Paragraph separator
-        || (codePoint >= 0x7f && codePoint <= 0x9f);
-  }
-
-  private static void appendHexJavaScriptRepresentation(int codePoint, Appendable out)
-      throws IOException {
-    if (Character.isSupplementaryCodePoint(codePoint)) {
-      // Handle supplementary unicode values which are not representable in
-      // javascript.  We deal with these by escaping them as two 4B sequences
-      // so that they will round-trip properly when sent from java to javascript
-      // and back.
-      char[] surrogates = Character.toChars(codePoint);
-      appendHexJavaScriptRepresentation(surrogates[0], out);
-      appendHexJavaScriptRepresentation(surrogates[1], out);
-      return;
-    }
-    out.append("\\u")
-        .append(HEX_CHARS[(codePoint >>> 12) & 0xf])
-        .append(HEX_CHARS[(codePoint >>> 8) & 0xf])
-        .append(HEX_CHARS[(codePoint >>> 4) & 0xf])
-        .append(HEX_CHARS[codePoint & 0xf]);
-  }
-}

gson/src/main/java/com/google/gson/JsonArray.java

@@ -16,7 +16,6 @@
 
 package com.google.gson;
 
-import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.ArrayList;
@@ -316,19 +315,4 @@ public final class JsonArray extends JsonElement implements Iterable<JsonElement
   public int hashCode() {
     return elements.hashCode();
   }
-
-  @Override
-  protected void toString(Appendable sb, Escaper escaper) throws IOException {
-    sb.append('[');
-    boolean first = true;
-    for (JsonElement element : elements) {
-      if (first) {
-        first = false;
-      } else {
-        sb.append(',');
-      }
-      element.toString(sb, escaper);
-    }
-    sb.append(']');
-  }
 }

gson/src/main/java/com/google/gson/JsonElement.java

@@ -16,7 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.stream.JsonWriter;
 import java.io.IOException;
+import java.io.StringWriter;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
@@ -28,8 +30,6 @@ import java.math.BigInteger;
  * @author Joel Leitch
  */
 public abstract class JsonElement {
-  private static final Escaper BASIC_ESCAPER = new Escaper(false);
-
   /**
    * provides check for verifying if this element is an array or not.
    *
@@ -325,19 +325,17 @@ public abstract class JsonElement {
 
   /**
    * Returns a String representation of this element.
-   *
-   * @return String the string representation of this element.
    */
   @Override
   public String toString() {
     try {
-      StringBuilder sb = new StringBuilder();
+      StringWriter stringWriter = new StringWriter();
-      toString(sb, BASIC_ESCAPER);
+      JsonWriter jsonWriter = new JsonWriter(stringWriter);
-      return sb.toString();
+      jsonWriter.setLenient(true);
+      Streams.write(this, true, jsonWriter);
+      return stringWriter.toString();
     } catch (IOException e) {
-      throw new RuntimeException(e);
+      throw new AssertionError(e);
     }
   }
-
-  protected abstract void toString(Appendable sb, Escaper escaper) throws IOException;
 }

gson/src/main/java/com/google/gson/JsonNull.java

@@ -16,8 +16,6 @@
 
 package com.google.gson;
 
-import java.io.IOException;
-
 /**
  * A class representing a Json {@code null} value.
  *
@@ -46,11 +44,6 @@ public final class JsonNull extends JsonElement {
     return this; // immutable!
   }
 
-  @Override
-  protected void toString(Appendable sb, Escaper escaper) throws IOException {
-    sb.append("null");
-  }
-
   /**
    * All instances of JsonNull have the same hash code since they are indistinguishable
    */

gson/src/main/java/com/google/gson/JsonObject.java

@@ -17,8 +17,6 @@
 package com.google.gson;
 
 import com.google.gson.internal.$Gson$Preconditions;
-
-import java.io.IOException;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
@@ -210,22 +208,4 @@ public final class JsonObject extends JsonElement {
   public int hashCode() {
     return members.hashCode();
   }
-
-  @Override
-  protected void toString(Appendable sb, Escaper escaper) throws IOException {
-    sb.append('{');
-    boolean first = true;
-    for (Map.Entry<String, JsonElement> entry : members.entrySet()) {
-      if (first) {
-        first = false;
-      } else {
-        sb.append(',');
-      }
-      sb.append('\"');
-      sb.append(escaper.escapeJsonString(entry.getKey()));
-      sb.append("\":");
-      entry.getValue().toString(sb, escaper);
-    }
-    sb.append('}');
-  }
 }

gson/src/main/java/com/google/gson/JsonPrimitive.java

@@ -17,8 +17,6 @@
 package com.google.gson;
 
 import com.google.gson.internal.$Gson$Preconditions;
-
-import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
@@ -294,17 +292,6 @@ public final class JsonPrimitive extends JsonElement {
     return value;
   }
 
-  @Override
-  protected void toString(Appendable sb, Escaper escaper) throws IOException {
-    if (isString()) {
-      sb.append('"');
-      sb.append(escaper.escapeJsonString(value.toString()));
-      sb.append('"');
-    } else {
-      sb.append(value.toString());
-    }
-  }
-
   private static boolean isPrimitiveOrString(Object target) {
     if (target instanceof String) {
       return true;

gson/src/test/java/com/google/gson/EscaperTest.java

@@ -1,189 +0,0 @@
-/*
- * Copyright (C) 2008 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.gson;
-
-import junit.framework.TestCase;
-
-/**
- * Performs some unit testing for the {@link Escaper} class.
- *
- * @author Joel Leitch
- */
-public class EscaperTest extends TestCase {
-
-  private Escaper escapeHtmlChar;
-  private Escaper noEscapeHtmlChar;
-  
-  @Override
-  protected void setUp() throws Exception {
-    super.setUp();
-    escapeHtmlChar = new Escaper(true);
-    noEscapeHtmlChar = new Escaper(false);
-  }
-
-  public void testNoSpecialCharacters() {
-    String value = "Testing123";
-    String escapedString = escapeHtmlChar.escapeJsonString(value);
-    assertEquals(value, escapedString);
-  }
-
-  public void testNewlineEscaping() throws Exception {
-    String containsNewline = "123\n456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsNewline);
-    assertEquals("123\\n456", escapedString);
-  }
-
-  public void testCarrageReturnEscaping() throws Exception {
-    String containsCarrageReturn = "123\r456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsCarrageReturn);
-    assertEquals("123\\r456", escapedString);
-  }
-
-  public void testTabEscaping() throws Exception {
-    String containsTab = "123\t456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsTab);
-    assertEquals("123\\t456", escapedString);
-  }
-
-  public void testDoubleQuoteEscaping() throws Exception {
-    String containsQuote = "123\"456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsQuote);
-    assertEquals("123\\\"456", escapedString);
-  }
-  
-  public void testSingleQuoteEscaping() throws Exception {
-    String containsQuote = "123'456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsQuote);
-    assertEquals("123\\u0027456", escapedString);
-  }
-
-  public void testLineSeparatorEscaping() throws Exception {
-    String src = "123\u2028 456";
-    String escapedString = escapeHtmlChar.escapeJsonString(src);
-    assertEquals("123\\u2028 456", escapedString);
-  }
-
-  public void testParagraphSeparatorEscaping() throws Exception {
-    String src = "123\u2029 456";
-    String escapedString = escapeHtmlChar.escapeJsonString(src);
-    assertEquals("123\\u2029 456", escapedString);
-  }
-
-  public void testControlCharBlockEscaping() throws Exception {
-    for (char c = '\u007f'; c <= '\u009f'; ++c) {
-      String src = "123 " + c + " 456";
-      String escapedString = escapeHtmlChar.escapeJsonString(src);
-      assertFalse(src.equals(escapedString));
-    }
-  }
-
-  public void testEqualsEscaping() throws Exception {
-    String containsEquals = "123=456";
-    int index = containsEquals.indexOf('=');
-    String unicodeValue = convertToUnicodeString(Character.codePointAt(containsEquals, index));
-    String escapedString = escapeHtmlChar.escapeJsonString(containsEquals);
-    assertEquals("123" + unicodeValue + "456", escapedString);
-    
-    escapedString = noEscapeHtmlChar.escapeJsonString(containsEquals);
-    assertEquals(containsEquals, escapedString);
-  }
-
-  public void testGreaterThanAndLessThanEscaping() throws Exception {
-    String containsLtGt = "123>456<";
-    int gtIndex = containsLtGt.indexOf('>');
-    int ltIndex = containsLtGt.indexOf('<');
-    String gtAsUnicode = convertToUnicodeString(Character.codePointAt(containsLtGt, gtIndex));
-    String ltAsUnicode = convertToUnicodeString(Character.codePointAt(containsLtGt, ltIndex));
-
-    String escapedString = escapeHtmlChar.escapeJsonString(containsLtGt);
-    assertEquals("123" + gtAsUnicode + "456" + ltAsUnicode, escapedString);
-    
-    escapedString = noEscapeHtmlChar.escapeJsonString(containsLtGt);
-    assertEquals(containsLtGt, escapedString);
-  }
-
-  public void testAmpersandEscaping() throws Exception {
-    String containsAmp = "123&456";
-    int ampIndex = containsAmp.indexOf('&');
-    String ampAsUnicode = convertToUnicodeString(Character.codePointAt(containsAmp, ampIndex));
-
-    String escapedString = escapeHtmlChar.escapeJsonString(containsAmp);
-    assertEquals("123" + ampAsUnicode + "456", escapedString);
-    
-    escapedString = noEscapeHtmlChar.escapeJsonString(containsAmp);
-    assertEquals(containsAmp, escapedString);
-
-    char ampCharAsUnicode = '\u0026';
-    String containsAmpUnicode = "123" + ampCharAsUnicode + "456";
-    escapedString = escapeHtmlChar.escapeJsonString(containsAmpUnicode);
-    assertEquals("123" + ampAsUnicode + "456", escapedString);
-
-    escapedString = noEscapeHtmlChar.escapeJsonString(containsAmpUnicode);
-    assertEquals(containsAmp, escapedString);
-  }
-
-  public void testSlashEscaping() throws Exception {
-    String containsSlash = "123\\456";
-    String escapedString = escapeHtmlChar.escapeJsonString(containsSlash);
-    assertEquals("123\\\\456", escapedString);
-  }
-
-  public void testSingleQuoteNotEscaped() throws Exception {
-    String containsSingleQuote = "123'456";
-    String escapedString = noEscapeHtmlChar.escapeJsonString(containsSingleQuote);
-    assertEquals(containsSingleQuote, escapedString);
-  }
-
-  public void testRequiredEscapingUnicodeCharacter() throws Exception {
-    char unicodeChar = '\u2028';
-    String unicodeString = "Testing" + unicodeChar;
-
-    String escapedString = escapeHtmlChar.escapeJsonString(unicodeString);
-    assertFalse(unicodeString.equals(escapedString));
-    assertEquals("Testing\\u2028", escapedString);
-  }
-
-  public void testUnicodeCharacterStringNoEscaping() throws Exception {
-    String unicodeString = "\u0065\u0066";
-
-    String escapedString = escapeHtmlChar.escapeJsonString(unicodeString);
-    assertEquals(unicodeString, escapedString);
-  }
-
-  /*
-  public void testChineseCharacterEscaping() throws Exception {
-    String unicodeString = "\u597d\u597d\u597d";
-    String chineseString = "好好好";
-    assertEquals(unicodeString, chineseString);
-
-    String expectedEscapedString = "\\u597d\\u597d\\u597d";
-    String escapedString = Escaper.escapeJsonString(chineseString);
-    assertEquals(expectedEscapedString, escapedString);
-  }
-   */
-
-  private String convertToUnicodeString(int codepoint) {
-    String hexValue = Integer.toHexString(codepoint);
-    StringBuilder sb = new StringBuilder("\\u");
-    for (int i = 0; i < 4 - hexValue.length(); i++) {
-      sb.append(0);
-    }
-    sb.append(hexValue);
-
-    return sb.toString().toLowerCase();
-  }
-}