/*
* Copyright 1999-2011 Alibaba Group.
*
* 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.alibaba.dubbo.common.json;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import com.alibaba.dubbo.common.bytecode.Wrapper;
import com.alibaba.dubbo.common.utils.Stack;
/**
* JSON.
*
* @author qian.lei
*/
public class JSON
{
public static final char LBRACE = '{', RBRACE = '}';
public static final char LSQUARE = '[', RSQUARE = ']';
public static final char COMMA = ',', COLON = ':', QUOTE = '"';
public static final String NULL = "null";
static final JSONConverter DEFAULT_CONVERTER = new GenericJSONConverter();
// state.
public static final byte END = 0, START = 1, OBJECT_ITEM = 2, OBJECT_VALUE = 3, ARRAY_ITEM = 4;
private static class Entry
{
byte state;
Object value;
Entry(byte s, Object v){ state = s; value = v; }
}
private JSON(){}
/**
* json string.
*
* @param obj object.
* @return json string.
* @throws IOException.
*/
public static String json(Object obj) throws IOException
{
if( obj == null ) return NULL;
StringWriter sw = new StringWriter();
try
{
json(obj, sw);
return sw.getBuffer().toString();
}
finally{ sw.close(); }
}
/**
* write json.
*
* @param obj object.
* @param writer writer.
* @throws IOException.
*/
public static void json(Object obj, Writer writer) throws IOException
{
json(obj, writer, false);
}
public static void json(Object obj, Writer writer, boolean writeClass) throws IOException
{
if( obj == null )
writer.write(NULL);
else
json(obj, new JSONWriter(writer), writeClass);
}
/**
* json string.
*
* @param obj object.
* @param properties property name array.
* @return json string.
* @throws IOException.
*/
public static String json(Object obj, String[] properties) throws IOException
{
if( obj == null ) return NULL;
StringWriter sw = new StringWriter();
try
{
json(obj, properties, sw);
return sw.getBuffer().toString();
}
finally{ sw.close(); }
}
public static void json(Object obj, final String[] properties, Writer writer) throws IOException
{
json(obj, properties, writer, false);
}
/**
* write json.
*
* @param obj object.
* @param properties property name array.
* @param writer writer.
* @throws IOException.
*/
public static void json(Object obj, final String[] properties, Writer writer, boolean writeClass) throws IOException
{
if( obj == null )
writer.write(NULL);
else
json(obj, properties, new JSONWriter(writer), writeClass);
}
private static void json(Object obj, JSONWriter jb, boolean writeClass) throws IOException
{
if( obj == null )
jb.valueNull();
else
DEFAULT_CONVERTER.writeValue(obj, jb, writeClass);
}
private static void json(Object obj, String[] properties, JSONWriter jb, boolean writeClass) throws IOException
{
if( obj == null )
{
jb.valueNull();
}
else
{
Wrapper wrapper = Wrapper.getWrapper(obj.getClass());
Object value;
jb.objectBegin();
for( String prop : properties )
{
jb.objectItem(prop);
value = wrapper.getPropertyValue(obj, prop);
if( value == null )
jb.valueNull();
else
DEFAULT_CONVERTER.writeValue(value, jb, writeClass);
}
jb.objectEnd();
}
}
/**
* parse json.
*
* @param json json source.
* @return JSONObject or JSONArray or Boolean or Long or Double or String or null
* @throws ParseException
*/
public static Object parse(String json) throws ParseException
{
StringReader reader = new StringReader(json);
try{ return parse(reader); }
catch(IOException e){ throw new ParseException(e.getMessage()); }
finally{ reader.close(); }
}
/**
* parse json.
*
* @param reader reader.
* @return JSONObject or JSONArray or Boolean or Long or Double or String or null
* @throws IOException
* @throws ParseException
*/
public static Object parse(Reader reader) throws IOException, ParseException
{
return parse(reader, JSONToken.ANY);
}
/**
* parse json.
*
* @param json json string.
* @param type target type.
* @return result.
* @throws ParseException
*/
public static <T> T parse(String json, Class<T> type) throws ParseException
{
StringReader reader = new StringReader(json);
try{ return parse(reader, type); }
catch(IOException e){ throw new ParseException(e.getMessage()); }
finally{ reader.close(); }
}
/**
* parse json
*
* @param reader json source.
* @param type target type.
* @return result.
* @throws IOException
* @throws ParseException
*/
@SuppressWarnings("unchecked")
public static <T> T parse(Reader reader, Class<T> type) throws IOException, ParseException
{
return (T)parse(reader, new J2oVisitor(type, DEFAULT_CONVERTER), JSONToken.ANY);
}
/**
* parse json.
*
* @param json json string.
* @param types target type array.
* @return result.
* @throws ParseException
*/
public static Object[] parse(String json, Class<?>[] types) throws ParseException
{
StringReader reader = new StringReader(json);
try{ return (Object[])parse(reader, types); }
catch(IOException e){ throw new ParseException(e.getMessage()); }
finally{ reader.close(); }
}
/**
* parse json.
*
* @param reader json source.
* @param types target type array.
* @return result.
* @throws IOException
* @throws ParseException
*/
public static Object[] parse(Reader reader, Class<?>[] types) throws IOException, ParseException
{
return (Object[])parse(reader, new J2oVisitor(types, DEFAULT_CONVERTER), JSONToken.LSQUARE);
}
/**
* parse json.
*
* @param json json string.
* @param handler handler.
* @return result.
* @throws ParseException
*/
public static Object parse(String json, JSONVisitor handler) throws ParseException
{
StringReader reader = new StringReader(json);
try{ return parse(reader, handler); }
catch(IOException e){ throw new ParseException(e.getMessage()); }
finally{ reader.close(); }
}
/**
* parse json.
*
* @param reader json source.
* @param handler handler.
* @return resule.
* @throws IOException
* @throws ParseException
*/
public static Object parse(Reader reader, JSONVisitor handler) throws IOException, ParseException
{
return parse(reader, handler, JSONToken.ANY);
}
private static Object parse(Reader reader, int expect) throws IOException, ParseException
{
JSONReader jr = new JSONReader(reader);
JSONToken token = jr.nextToken(expect);
byte state = START;
Object value = null, tmp;
Stack<Entry> stack = new Stack<Entry>();
do
{
switch( state )
{
case END:
throw new ParseException("JSON source format error.");
case START:
{
switch( token.type )
{
case JSONToken.NULL: case JSONToken.BOOL: case JSONToken.INT: case JSONToken.FLOAT: case JSONToken.STRING:
{
state = END;
value = token.value;
break;
}
case JSONToken.LSQUARE:
{
state = ARRAY_ITEM;
value = new JSONArray();
break;
}
case JSONToken.LBRACE:
{
state = OBJECT_ITEM;
value = new JSONObject();
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case ARRAY_ITEM:
{
switch( token.type )
{
case JSONToken.COMMA:
break;
case JSONToken.NULL: case JSONToken.BOOL: case JSONToken.INT: case JSONToken.FLOAT: case JSONToken.STRING:
{
((JSONArray)value).add(token.value);
break;
}
case JSONToken.RSQUARE: // end of array.
{
if( stack.isEmpty() )
{
state = END;
}
else
{
Entry entry = stack.pop();
state = entry.state;
value = entry.value;
}
break;
}
case JSONToken.LSQUARE: // array begin.
{
tmp = new JSONArray();
((JSONArray)value).add(tmp);
stack.push(new Entry(state, value));
state = ARRAY_ITEM;
value = tmp;
break;
}
case JSONToken.LBRACE: // object begin.
{
tmp = new JSONObject();
((JSONArray)value).add(tmp);
stack.push(new Entry(state, value));
state = OBJECT_ITEM;
value = tmp;
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or ',' or ']' or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case OBJECT_ITEM:
{
switch( token.type )
{
case JSONToken.COMMA:
break;
case JSONToken.IDENT: // item name.
{
stack.push(new Entry(OBJECT_ITEM, (String)token.value));
state = OBJECT_VALUE;
break;
}
case JSONToken.NULL:
{
stack.push(new Entry(OBJECT_ITEM, "null"));
state = OBJECT_VALUE;
break;
}
case JSONToken.BOOL: case JSONToken.INT: case JSONToken.FLOAT: case JSONToken.STRING:
{
stack.push(new Entry(OBJECT_ITEM, token.value.toString()));
state = OBJECT_VALUE;
break;
}
case JSONToken.RBRACE: // end of object.
{
if( stack.isEmpty() )
{
state = END;
}
else
{
Entry entry = stack.pop();
state = entry.state;
value = entry.value;
}
break;
}
default:
throw new ParseException("Unexcepted token expect [ IDENT or VALUE or ',' or '}' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case OBJECT_VALUE:
{
switch( token.type )
{
case JSONToken.COLON:
break;
case JSONToken.NULL: case JSONToken.BOOL: case JSONToken.INT: case JSONToken.FLOAT: case JSONToken.STRING:
{
((JSONObject)value).put((String)stack.pop().value, token.value);
state = OBJECT_ITEM;
break;
}
case JSONToken.LSQUARE: // array begin.
{
tmp = new JSONArray();
((JSONObject)value).put((String)stack.pop().value, tmp);
stack.push(new Entry(OBJECT_ITEM, value));
state = ARRAY_ITEM;
value = tmp;
break;
}
case JSONToken.LBRACE: // object begin.
{
tmp = new JSONObject();
((JSONObject)value).put((String)stack.pop().value, tmp);
stack.push(new Entry(OBJECT_ITEM, value));
state = OBJECT_ITEM;
value = tmp;
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
default:
throw new ParseException("Unexcepted state.");
}
}
while( ( token = jr.nextToken() ) != null );
stack.clear();
return value;
}
private static Object parse(Reader reader, JSONVisitor handler, int expect) throws IOException, ParseException
{
JSONReader jr = new JSONReader(reader);
JSONToken token = jr.nextToken(expect);
Object value = null;
int state = START, index = 0;
Stack<int[]> states = new Stack<int[]>();
boolean pv = false;
handler.begin();
do
{
switch( state )
{
case END:
throw new ParseException("JSON source format error.");
case START:
{
switch( token.type )
{
case JSONToken.NULL:
{
value = token.value;
state = END;
pv = true;
break;
}
case JSONToken.BOOL:
{
value = token.value;
state = END;
pv = true;
break;
}
case JSONToken.INT:
{
value = token.value;
state = END;
pv = true;
break;
}
case JSONToken.FLOAT:
{
value = token.value;
state = END;
pv = true;
break;
}
case JSONToken.STRING:
{
value = token.value;
state = END;
pv = true;
break;
}
case JSONToken.LSQUARE:
{
handler.arrayBegin();
state = ARRAY_ITEM;
break;
}
case JSONToken.LBRACE:
{
handler.objectBegin();
state = OBJECT_ITEM;
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case ARRAY_ITEM:
{
switch( token.type )
{
case JSONToken.COMMA:
break;
case JSONToken.NULL:
{
handler.arrayItem(index++);
handler.arrayItemValue(index, token.value, true);
break;
}
case JSONToken.BOOL:
{
handler.arrayItem(index++);
handler.arrayItemValue(index, token.value, true);
break;
}
case JSONToken.INT:
{
handler.arrayItem(index++);
handler.arrayItemValue(index, token.value, true);
break;
}
case JSONToken.FLOAT:
{
handler.arrayItem(index++);
handler.arrayItemValue(index, token.value, true);
break;
}
case JSONToken.STRING:
{
handler.arrayItem(index++);
handler.arrayItemValue(index, token.value, true);
break;
}
case JSONToken.LSQUARE:
{
handler.arrayItem(index++);
states.push(new int[]{state, index});
index = 0;
state = ARRAY_ITEM;
handler.arrayBegin();
break;
}
case JSONToken.LBRACE:
{
handler.arrayItem(index++);
states.push(new int[]{state, index});
index = 0;
state = OBJECT_ITEM;
handler.objectBegin();
break;
}
case JSONToken.RSQUARE:
{
if( states.isEmpty() )
{
value = handler.arrayEnd(index);
state = END;
}
else
{
value = handler.arrayEnd(index);
int[] tmp = states.pop();
state = tmp[0];
index = tmp[1];
switch( state )
{
case ARRAY_ITEM:
{
handler.arrayItemValue(index, value, false);
break;
}
case OBJECT_ITEM:
{
handler.objectItemValue(value, false);
break;
}
}
}
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or ',' or ']' or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case OBJECT_ITEM:
{
switch( token.type )
{
case JSONToken.COMMA:
break;
case JSONToken.IDENT:
{
handler.objectItem((String)token.value);
state = OBJECT_VALUE;
break;
}
case JSONToken.NULL:
{
handler.objectItem("null");
state = OBJECT_VALUE;
break;
}
case JSONToken.BOOL: case JSONToken.INT: case JSONToken.FLOAT: case JSONToken.STRING:
{
handler.objectItem(token.value.toString());
state = OBJECT_VALUE;
break;
}
case JSONToken.RBRACE:
{
if( states.isEmpty() )
{
value = handler.objectEnd(index);
state = END;
}
else
{
value = handler.objectEnd(index);
int[] tmp = states.pop();
state = tmp[0];
index = tmp[1];
switch( state )
{
case ARRAY_ITEM:
{
handler.arrayItemValue(index, value, false);
break;
}
case OBJECT_ITEM:
{
handler.objectItemValue(value, false);
break;
}
}
}
break;
}
default:
throw new ParseException("Unexcepted token expect [ IDENT or VALUE or ',' or '}' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
case OBJECT_VALUE:
{
switch( token.type )
{
case JSONToken.COLON:
break;
case JSONToken.NULL:
{
handler.objectItemValue(token.value, true);
state = OBJECT_ITEM;
break;
}
case JSONToken.BOOL:
{
handler.objectItemValue(token.value, true);
state = OBJECT_ITEM;
break;
}
case JSONToken.INT:
{
handler.objectItemValue(token.value, true);
state = OBJECT_ITEM;
break;
}
case JSONToken.FLOAT:
{
handler.objectItemValue(token.value, true);
state = OBJECT_ITEM;
break;
}
case JSONToken.STRING:
{
handler.objectItemValue(token.value, true);
state = OBJECT_ITEM;
break;
}
case JSONToken.LSQUARE:
{
states.push(new int[]{OBJECT_ITEM, index});
index = 0;
state = ARRAY_ITEM;
handler.arrayBegin();
break;
}
case JSONToken.LBRACE:
{
states.push(new int[]{OBJECT_ITEM, index});
index = 0;
state = OBJECT_ITEM;
handler.objectBegin();
break;
}
default:
throw new ParseException("Unexcepted token expect [ VALUE or '[' or '{' ] get '" + JSONToken.token2string(token.type) + "'");
}
break;
}
default:
throw new ParseException("Unexcepted state.");
}
}
while( ( token = jr.nextToken() ) != null );
states.clear();
return handler.end(value, pv);
}
}