/*
* $Id: JSONParser.java,v 1.2 2008-08-07 01:18:55 parg Exp $
* Created on 2006-4-15
*/
package org.json.simple.parser;
import java.io.Reader;
import java.util.Stack;
import org.gudy.azureus2.core3.util.LightHashMap;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
/**
* @author FangYidong<fangyidong@yahoo.com.cn>
*/
public class JSONParser {
public static final int S_INIT=0;
public static final int S_IN_FINISHED_VALUE=1;//string,number,boolean,null,object,array
public static final int S_IN_OBJECT=2;
public static final int S_IN_ARRAY=3;
public static final int S_PASSED_PAIR_KEY=4;
public static final int S_IN_ERROR=-1;
private int peekStatus(Stack statusStack){
if(statusStack.size()==0)
return -1;
Integer status=(Integer)statusStack.peek();
return status.intValue();
}
public Object parse(Reader in) throws Exception{
Stack statusStack=new Stack();
Stack valueStack=new Stack();
Yylex lexer=new Yylex(in);
Yytoken token=null;
int status=S_INIT;
try{
do{
token=lexer.yylex();
if(token==null)
token=new Yytoken(Yytoken.TYPE_EOF,null);
switch(status){
case S_INIT:
switch(token.type){
case Yytoken.TYPE_VALUE:
status=S_IN_FINISHED_VALUE;
statusStack.push(new Integer(status));
valueStack.push(token.value);
break;
case Yytoken.TYPE_LEFT_BRACE:
status=S_IN_OBJECT;
statusStack.push(new Integer(status));
valueStack.push(new JSONObject());
break;
case Yytoken.TYPE_LEFT_SQUARE:
status=S_IN_ARRAY;
statusStack.push(new Integer(status));
valueStack.push(new JSONArray());
break;
default:
status=S_IN_ERROR;
}//inner switch
break;
case S_IN_FINISHED_VALUE:
if(token.type==Yytoken.TYPE_EOF)
return valueStack.pop();
else
return null;
case S_IN_OBJECT:
switch(token.type){
case Yytoken.TYPE_COMMA:
break;
case Yytoken.TYPE_VALUE:
if(token.value instanceof String){
String key=(String)token.value;
valueStack.push(key);
status=S_PASSED_PAIR_KEY;
statusStack.push(new Integer(status));
}
else{
status=S_IN_ERROR;
}
break;
case Yytoken.TYPE_RIGHT_BRACE:
if(valueStack.size()>1){
statusStack.pop();
JSONObject map = (JSONObject)valueStack.pop();
map.compactify(-0.9f);
status=peekStatus(statusStack);
}
else{
status=S_IN_FINISHED_VALUE;
}
break;
default:
status=S_IN_ERROR;
break;
}//inner switch
break;
case S_PASSED_PAIR_KEY:
switch(token.type){
case Yytoken.TYPE_COLON:
break;
case Yytoken.TYPE_VALUE:
statusStack.pop();
String key=(String)valueStack.pop();
JSONObject parent=(JSONObject)valueStack.peek();
parent.put(key,token.value);
status=peekStatus(statusStack);
break;
case Yytoken.TYPE_LEFT_SQUARE:
statusStack.pop();
key=(String)valueStack.pop();
parent=(JSONObject)valueStack.peek();
JSONArray newArray=new JSONArray();
parent.put(key,newArray);
status=S_IN_ARRAY;
statusStack.push(new Integer(status));
valueStack.push(newArray);
break;
case Yytoken.TYPE_LEFT_BRACE:
statusStack.pop();
key=(String)valueStack.pop();
parent=(JSONObject)valueStack.peek();
JSONObject newObject=new JSONObject();
parent.put(key,newObject);
status=S_IN_OBJECT;
statusStack.push(new Integer(status));
valueStack.push(newObject);
break;
default:
status=S_IN_ERROR;
}
break;
case S_IN_ARRAY:
switch(token.type){
case Yytoken.TYPE_COMMA:
break;
case Yytoken.TYPE_VALUE:
JSONArray val=(JSONArray)valueStack.peek();
val.add(token.value);
break;
case Yytoken.TYPE_RIGHT_SQUARE:
if(valueStack.size()>1){
statusStack.pop();
valueStack.pop();
status=peekStatus(statusStack);
}
else{
status=S_IN_FINISHED_VALUE;
}
break;
case Yytoken.TYPE_LEFT_BRACE:
val=(JSONArray)valueStack.peek();
JSONObject newObject=new JSONObject();
val.add(newObject);
status=S_IN_OBJECT;
statusStack.push(new Integer(status));
valueStack.push(newObject);
break;
case Yytoken.TYPE_LEFT_SQUARE:
val=(JSONArray)valueStack.peek();
JSONArray newArray=new JSONArray();
val.add(newArray);
status=S_IN_ARRAY;
statusStack.push(new Integer(status));
valueStack.push(newArray);
break;
default:
status=S_IN_ERROR;
}//inner switch
break;
case S_IN_ERROR:
return null;
}//switch
if(status==S_IN_ERROR)
return null;
}while(token.type!=Yytoken.TYPE_EOF);
}
catch(Exception e){
throw e;
}
return null;
}
}