/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 groovy.json;
import groovy.json.internal.CharBuf;
import groovy.json.internal.Chr;
import groovy.lang.Closure;
import groovy.util.Expando;
import java.io.StringReader;
import java.net.URL;
import java.util.*;
/**
* Class responsible for the actual String serialization of the possible values of a JSON structure.
* This class can also be used as a category, so as to add <code>toJson()</code> methods to various types.
* <p>
* This class does not provide the ability to customize the resulting output. A {@link JsonGenerator}
* can be used if the ability to alter the resulting output is required.
*
* @author Guillaume Laforge
* @author Roshan Dawrani
* @author Andrey Bloschetsov
* @author Rick Hightower
* @author Graeme Rocher
*
* @see JsonGenerator
* @since 1.8.0
*/
public class JsonOutput {
static final char OPEN_BRACKET = '[';
static final char CLOSE_BRACKET = ']';
static final char OPEN_BRACE = '{';
static final char CLOSE_BRACE = '}';
static final char COLON = ':';
static final char COMMA = ',';
static final char SPACE = ' ';
static final char NEW_LINE = '\n';
static final char QUOTE = '"';
static final char[] EMPTY_STRING_CHARS = Chr.array(QUOTE, QUOTE);
static final char[] EMPTY_MAP_CHARS = {OPEN_BRACE, CLOSE_BRACE};
static final char[] EMPTY_LIST_CHARS = {OPEN_BRACKET, CLOSE_BRACKET};
/* package-private for use in builders */
static final JsonGenerator DEFAULT_GENERATOR = new DefaultJsonGenerator(new JsonGenerator.Options());
/**
* @return "true" or "false" for a boolean value
*/
public static String toJson(Boolean bool) {
return DEFAULT_GENERATOR.toJson(bool);
}
/**
* @return a string representation for a number
* @throws JsonException if the number is infinite or not a number.
*/
public static String toJson(Number n) {
return DEFAULT_GENERATOR.toJson(n);
}
/**
* @return a JSON string representation of the character
*/
public static String toJson(Character c) {
return DEFAULT_GENERATOR.toJson(c);
}
/**
* @return a properly encoded string with escape sequences
*/
public static String toJson(String s) {
return DEFAULT_GENERATOR.toJson(s);
}
/**
* Format a date that is parseable from JavaScript, according to ISO-8601.
*
* @param date the date to format to a JSON string
* @return a formatted date in the form of a string
*/
public static String toJson(Date date) {
return DEFAULT_GENERATOR.toJson(date);
}
/**
* Format a calendar instance that is parseable from JavaScript, according to ISO-8601.
*
* @param cal the calendar to format to a JSON string
* @return a formatted date in the form of a string
*/
public static String toJson(Calendar cal) {
return DEFAULT_GENERATOR.toJson(cal);
}
/**
* @return the string representation of an uuid
*/
public static String toJson(UUID uuid) {
return DEFAULT_GENERATOR.toJson(uuid);
}
/**
* @return the string representation of the URL
*/
public static String toJson(URL url) {
return DEFAULT_GENERATOR.toJson(url);
}
/**
* @return an object representation of a closure
*/
public static String toJson(Closure closure) {
return DEFAULT_GENERATOR.toJson(closure);
}
/**
* @return an object representation of an Expando
*/
public static String toJson(Expando expando) {
return DEFAULT_GENERATOR.toJson(expando);
}
/**
* @return "null" for a null value, or a JSON array representation for a collection, array, iterator or enumeration,
* or representation for other object.
*/
public static String toJson(Object object) {
return DEFAULT_GENERATOR.toJson(object);
}
/**
* @return a JSON object representation for a map
*/
public static String toJson(Map m) {
return DEFAULT_GENERATOR.toJson(m);
}
/**
* Pretty print a JSON payload.
*
* @param jsonPayload
* @return a pretty representation of JSON payload.
*/
public static String prettyPrint(String jsonPayload) {
int indentSize = 0;
// Just a guess that the pretty view will take 20 percent more than original.
final CharBuf output = CharBuf.create((int) (jsonPayload.length() * 1.2));
JsonLexer lexer = new JsonLexer(new StringReader(jsonPayload));
// Will store already created indents.
Map<Integer, char[]> indentCache = new HashMap<Integer, char[]>();
while (lexer.hasNext()) {
JsonToken token = lexer.next();
switch (token.getType()) {
case OPEN_CURLY:
indentSize += 4;
output.addChars(Chr.array(OPEN_BRACE, NEW_LINE)).addChars(getIndent(indentSize, indentCache));
break;
case CLOSE_CURLY:
indentSize -= 4;
output.addChar(NEW_LINE);
if (indentSize > 0) {
output.addChars(getIndent(indentSize, indentCache));
}
output.addChar(CLOSE_BRACE);
break;
case OPEN_BRACKET:
indentSize += 4;
output.addChars(Chr.array(OPEN_BRACKET, NEW_LINE)).addChars(getIndent(indentSize, indentCache));
break;
case CLOSE_BRACKET:
indentSize -= 4;
output.addChar(NEW_LINE);
if (indentSize > 0) {
output.addChars(getIndent(indentSize, indentCache));
}
output.addChar(CLOSE_BRACKET);
break;
case COMMA:
output.addChars(Chr.array(COMMA, NEW_LINE)).addChars(getIndent(indentSize, indentCache));
break;
case COLON:
output.addChars(Chr.array(COLON, SPACE));
break;
case STRING:
String textStr = token.getText();
String textWithoutQuotes = textStr.substring(1, textStr.length() - 1);
if (textWithoutQuotes.length() > 0) {
output.addJsonEscapedString(textWithoutQuotes);
} else {
output.addQuoted(Chr.array());
}
break;
default:
output.addString(token.getText());
}
}
return output.toString();
}
/**
* Creates new indent if it not exists in the indent cache.
*
* @return indent with the specified size.
*/
private static char[] getIndent(int indentSize, Map<Integer, char[]> indentCache) {
char[] indent = indentCache.get(indentSize);
if (indent == null) {
indent = new char[indentSize];
Arrays.fill(indent, SPACE);
indentCache.put(indentSize, indent);
}
return indent;
}
/**
* Obtains JSON unescaped text for the given text
*
* @param text The text
* @return The unescaped text
*/
public static JsonUnescaped unescaped(CharSequence text) {
return new JsonUnescaped(text);
}
/**
* Represents unescaped JSON
*/
public static class JsonUnescaped {
private CharSequence text;
public JsonUnescaped(CharSequence text) {
this.text = text;
}
public CharSequence getText() {
return text;
}
@Override
public String toString() {
return text.toString();
}
}
}