content: /**
   * 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 org.apache.noggit;
  
  import java.util.*;
  import java.io.IOException;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  
  /**
   * @author yonik
   * @version $Id$
   */
  public class ObjectBuilder {
  
    public static Object fromJSON(String json) throws IOException {
      JSONParser p = new JSONParser(json);
      return getVal(p);
    }
  
    public static Object getVal(JSONParser parser) throws IOException {
      return new ObjectBuilder(parser).getVal();
    }
  
    final JSONParser parser;
    
    public ObjectBuilder(JSONParser parser) throws IOException {
      this.parser = parser;
      if (parser.lastEvent()==0) parser.nextEvent();
    }
  
  
    public Object getVal() throws IOException {
      int ev = parser.lastEvent();
      switch(ev) {
        case JSONParser.STRING: return getString();
        case JSONParser.LONG: return getLong();
        case JSONParser.NUMBER: return getNumber();
        case JSONParser.BIGNUMBER: return getBigNumber();
        case JSONParser.BOOLEAN: return getBoolean();
        case JSONParser.NULL: return getNull();
        case JSONParser.OBJECT_START: return getObject();
        case JSONParser.OBJECT_END: return null; // OR ERROR?
        case JSONParser.ARRAY_START: return getArray();
        case JSONParser.ARRAY_END: return  null; // OR ERROR?
        case JSONParser.EOF: return null; // OR ERROR?
        default: return null; // OR ERROR?
      }
    }
  
  
    public Object getString() throws IOException {
      return parser.getString();    
    }
  
    public Object getLong() throws IOException {
      return Long.valueOf(parser.getLong());    
    }
  
    public Object getNumber() throws IOException {
      CharArr num = parser.getNumberChars();
      String numstr = num.toString();
      double d = Double.parseDouble(numstr);
      if (!Double.isInfinite(d)) return Double.valueOf(d);
      // TODO: use more efficient constructor in Java5
      return new BigDecimal(numstr);
    }
  
    public Object getBigNumber() throws IOException {
      CharArr num = parser.getNumberChars();
      String numstr = num.toString();
      for(int ch; (ch=num.read())!=-1;) {
        if (ch=='.' || ch=='e' || ch=='E') return new BigDecimal(numstr);
      }
      return new BigInteger(numstr);
    }
  
    public Object getBoolean() throws IOException {
      return parser.getBoolean();
    }
  
    public Object getNull() throws IOException {
      parser.getNull();
      return null;
    }
  
    public Object newObject() throws IOException {
      return new LinkedHashMap();
    }
  
    public Object getKey() throws IOException {
      return parser.getString();
    }
  
    public void addKeyVal(Object map, Object key, Object val) throws IOException {
      Object prev = ((Map)map).put(key,val);
      // TODO: test for repeated value?
    }
  
    public Object objectEnd(Object obj) {
      return obj;
    }
  
  
    public Object getObject() throws IOException {
      Object m = newObject();
      for(;;) {
        int ev = parser.nextEvent();
        if (ev==JSONParser.OBJECT_END) return objectEnd(m);
        Object key = getKey();
        ev = parser.nextEvent();      
        Object val = getVal();
        addKeyVal(m, key, val);
      }
    }
  
    public Object newArray() {
      return new ArrayList();
    }
  
    public void addArrayVal(Object arr, Object val) throws IOException {
      ((List)arr).add(val);
    }
  
    public Object endArray(Object arr) {
      return arr;
    }
    
    public Object getArray() throws IOException {
      Object arr = newArray();
      for(;;) {
        int ev = parser.nextEvent();
        if (ev==JSONParser.ARRAY_END) return endArray(arr);
        Object val = getVal();
        addArrayVal(arr, val);
      }
    }
  
  }
  