/*
* Copyright (C) 2006 Joe Walnes.
* Copyright (C) 2006, 2007, 2008, 2009, 2011 XStream Committers.
* All rights reserved.
*
* The software in this package is published under the terms of the BSD
* style license a copy of which has been included with this distribution in
* the LICENSE.txt file.
*
* Created on 28. November 2008 by Joerg Schaible
*/
package com.thoughtworks.xstream.io.json;
import java.io.Writer;
import com.thoughtworks.xstream.converters.ConversionException;
import com.thoughtworks.xstream.core.util.QuickWriter;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
/**
* A simple writer that outputs JSON in a pretty-printed indented stream. Arrays, Lists and Sets
* rely on you NOT using XStream.addImplicitCollection(..).
*
* @author Paul Hammant
* @author Jörg Schaible
* @since 1.3.1
*/
public class JsonWriter extends AbstractJsonWriter {
protected final QuickWriter writer;
protected final Format format;
private int depth;
private boolean newLineProposed;
/**
* @deprecated As of 1.4 use {@link JsonWriter#JsonWriter(Writer, Format) instead}
*/
public JsonWriter(Writer writer, char[] lineIndenter, String newLine) {
this(writer, 0, new Format(
lineIndenter, newLine.toCharArray(), Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* @deprecated As of 1.4 use {@link JsonWriter#JsonWriter(Writer, Format) instead}
*/
public JsonWriter(Writer writer, char[] lineIndenter) {
this(writer, 0, new Format(lineIndenter, new char[]{'\n'}, Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* @deprecated As of 1.4 use {@link JsonWriter#JsonWriter(Writer, Format) instead}
*/
public JsonWriter(Writer writer, String lineIndenter, String newLine) {
this(writer, 0, new Format(
lineIndenter.toCharArray(), newLine.toCharArray(), Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* @deprecated As of 1.4 use {@link JsonWriter#JsonWriter(Writer, Format) instead}
*/
public JsonWriter(Writer writer, String lineIndenter) {
this(writer, 0, new Format(
lineIndenter.toCharArray(), new char[]{'\n'}, Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
public JsonWriter(Writer writer) {
this(writer, 0, new Format(
new char[]{' ', ' '}, new char[]{'\n'}, Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* @since 1.3.1
* @deprecated As of 1.4 use {@link JsonWriter#JsonWriter(Writer, int, Format) instead}
*/
public JsonWriter(Writer writer, char[] lineIndenter, String newLine, int mode) {
this(writer, mode, new Format(
lineIndenter, newLine.toCharArray(), Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* Create a JsonWriter where the writer mode can be chosen.
*
* @param writer the {@link Writer} where the JSON is written to
* @param mode the JsonWriter mode
* @since 1.3.1
* @see #JsonWriter(Writer, int, Format)
*/
public JsonWriter(Writer writer, int mode) {
this(writer, mode, new Format(
new char[]{' ', ' '}, new char[]{'\n'}, Format.SPACE_AFTER_LABEL
| Format.COMPACT_EMPTY_ELEMENT));
}
/**
* Create a JsonWriter where the format is provided.
*
* @param writer the {@link Writer} where the JSON is written to
* @param format the JSON format definition
* @since 1.4
* @see #JsonWriter(Writer, int, Format)
*/
public JsonWriter(Writer writer, Format format) {
this(writer, 0, format);
}
/**
* Create a JsonWriter where the writer mode can be chosen and the format definition is
* provided.
* <p>
* Following constants can be used as bit mask for the mode:
* <ul>
* <li>{@link #DROP_ROOT_MODE}: drop the root node</li>
* <li>{@link #STRICT_MODE}: do not throw {@link ConversionException}, if writer should
* generate invalid JSON</li>
* <li>{@link #EXPLICIT_MODE}: ensure that all available data is explicitly written even if
* addition objects must be added</li>
* </ul>
* </p>
*
* @param writer the {@link Writer} where the JSON is written to
* @param mode the JsonWriter mode
* @param format the JSON format definition
* @since 1.4
*/
public JsonWriter(Writer writer, int mode, Format format) {
this(writer, mode, format, 1024);
}
/**
* Create a JsonWriter.
*
* @param writer the {@link Writer} where the JSON is written to
* @param mode the JsonWriter mode
* @param format the JSON format definition
* @param bufferSize the buffer size of the internally used QuickWriter
* @see JsonWriter#JsonWriter(Writer, int, Format)
* @since 1.4
*/
public JsonWriter(Writer writer, int mode, Format format, int bufferSize) {
super(mode);
this.writer = new QuickWriter(writer, bufferSize);
this.format = format;
depth = (mode & DROP_ROOT_MODE) == 0 ? -1 : 0;
}
public void flush() {
writer.flush();
}
public void close() {
writer.close();
}
public HierarchicalStreamWriter underlyingWriter() {
return this;
}
/**
* {@inheritDoc}
*/
protected void startObject() {
if (newLineProposed) {
writeNewLine();
}
writer.write('{');
startNewLine();
}
/**
* {@inheritDoc}
*/
protected void addLabel(String name) {
if (newLineProposed) {
writeNewLine();
}
writer.write('"');
writeText(name);
writer.write("\":");
if ((format.mode() & Format.SPACE_AFTER_LABEL) != 0) {
writer.write(' ');
}
}
/**
* {@inheritDoc}
*/
protected void addValue(String value, Type type) {
if (newLineProposed) {
writeNewLine();
}
if (type == Type.STRING) {
writer.write('"');
}
writeText(value);
if (type == Type.STRING) {
writer.write('"');
}
}
/**
* {@inheritDoc}
*/
protected void startArray() {
if (newLineProposed) {
writeNewLine();
}
writer.write("[");
startNewLine();
}
/**
* {@inheritDoc}
*/
protected void nextElement() {
writer.write(",");
writeNewLine();
}
/**
* {@inheritDoc}
*/
protected void endArray() {
endNewLine();
writer.write("]");
}
/**
* {@inheritDoc}
*/
protected void endObject() {
endNewLine();
writer.write("}");
}
private void startNewLine() {
if ( ++depth > 0) {
newLineProposed = true;
}
}
private void endNewLine() {
if (depth-- > 0) {
if (((format.mode() & Format.COMPACT_EMPTY_ELEMENT) != 0) && newLineProposed) {
newLineProposed = false;
} else {
writeNewLine();
}
}
}
private void writeNewLine() {
int depth = this.depth;
writer.write(format.getNewLine());
while (depth-- > 0) {
writer.write(format.getLineIndenter());
}
newLineProposed = false;
}
private void writeText(String text) {
int length = text.length();
for (int i = 0; i < length; i++ ) {
char c = text.charAt(i);
switch (c) {
case '"':
this.writer.write("\\\"");
break;
case '\\':
this.writer.write("\\\\");
break;
default:
if (c > 0x1f) {
this.writer.write(c);
} else {
this.writer.write("\\u");
String hex = "000" + Integer.toHexString(c);
this.writer.write(hex.substring(hex.length() - 4));
}
}
}
}
/**
* Format definition for JSON.
*
* @author Jörg Schaible
* @since 1.4
*/
public static class Format {
public static int SPACE_AFTER_LABEL = 1;
public static int COMPACT_EMPTY_ELEMENT = 2;
private char[] lineIndenter;
private char[] newLine;
private final int mode;
/**
* Create a new Formatter.
*
* @param lineIndenter the characters used for indenting the line
* @param newLine the characters used to create a new line
* @param mode the flags for the format modes
* @since 1.4
*/
public Format(char[] lineIndenter, char[] newLine, int mode) {
this.lineIndenter = lineIndenter;
this.newLine = newLine;
this.mode = mode;
}
/**
* Retrieve the lineIndenter.
*
* @return the lineIndenter
* @since 1.4
*/
public char[] getLineIndenter() {
return this.lineIndenter;
}
/**
* Retrieve the newLine.
*
* @return the newLine
* @since 1.4
*/
public char[] getNewLine() {
return this.newLine;
}
/**
* Retrieve the mode flags of the formatter.
*
* @return the mode
* @since 1.4
*/
public int mode() {
return this.mode;
}
}
}