var people={"programmers":[{"firstName":"Brett","lastName":"McLaughlin","email":"aaaa"}, 
{"firstName":"Jason","lastName":"Hunter","email":"bbbb"}, 
{"firstName":"Elliotte","lastName":"Harold","email":"cccc"}
],
"authors":[ {"firstName":"Isaac","lastName":"Asimov","genre":"sciencefiction"}, 
{"firstName":"Tad","lastName":"Williams","genre":"fantasy"}, 
{"firstName":"Frank","lastName":"Peretti","genre":"christianfiction"}
],
"musicians":[ {"firstName":"Eric","lastName":"Clapton","instrument":"guitar"}, 
{"firstName":"Sergei","lastName":"Rachmaninoff","instrument":"piano"}
]} 

7.实例比较

<?xmlversion="1.0"encoding="utf-8"?>
<country>
    <name>中国</name>
    <province>
        <name>黑龙江</name>
        <cities>
           <city>哈尔滨</city>
           <city>大庆</city>
        </cities>
    </province>
    <province>
        <name>广东</name>
        <cities>
           <city>广州</city>
           <city>深圳</city>
           <city>珠海</city>
        </cities>
    </province>
    <province>
        <name>台湾</name>
        <cities>
           <city>台北</city>
           <city>高雄</city>
        </cities>
    </province>
    <province>
        <name>新疆</name>
        <cities>
           <city>乌鲁木齐</city>
        </cities>
    </province>
</country>

{
    "name": "中国",
    "province": [
        {
            "name": "黑龙江",
            "cities": {
                "city": ["哈尔滨","大庆"]
            }
        },
        {
            "name": "广东",
            "cities": {
                "city": ["广州","深圳","珠海"]
            }
        },
        {
            "name": "台湾",
            "cities": {
                "city": ["台北","高雄"]
            }
        },
        {
            "name": "新疆",
            "cities": {
                "city": ["乌鲁木齐"]
            }
        }
    ]
}

8.JSON操作

1、JSON字符串转换成JAVAScript对象(调用eval())

JSON本来就是JS的一个子集，所以可以使用JS的解释器

<script>
  var my_json='{"FBI":[{"name":"rose","age":"25"},{"name":"jack","age":"25"}],"NBA":[{"name":"tom","sex":"man"},{"name":"jack","sex":"women"}]}';
  var my_object=eval('('+my_json+')');
  document.writeln(my_object.FBI[1].name);
</script>

 var my_json='{FBI:[{name:"rose",age:"25"},{name:"jack",age:"25"}],NBA:[{name:"tom",sex:"man"},{name:"jack",sex:"women"}]}';

2、将JS对象转换成JSON字符串(调用toJSONString())

需要下载json.js(http://www.json.org/json.js)

<script src=http://www.mamicode.com/"json.js"></script>>
3、XML与JSON转换
(需要下载json.org提供的JAVA类，json.zip[http://www.json.org/java/json.zip])
package away;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;

import org.json.JSONObject;
import org.json.XML;

public class XMl2JSON {


    public static void main(String[] args) {
        BufferedReader buffRed=null;
        BufferedWriter buffWri=null;
        try{
            //将XML转换成JSON
            String fileName1="away.xml";
            buffRed=new BufferedReader(new FileReader(fileName1));
            String tempStr;
            StringBuffer xmlStrBuff=new StringBuffer();
            while((tempStr=buffRed.readLine())!=null)
                xmlStrBuff.append(tempStr);
            System.out.println("JSON str="+XML.toJSONObject(xmlStrBuff.toString()));
            
            //将JSON转换成XML
            String jsonStr="{Heros:{FBI:[{name:\"rose\",age:\"25\"},{name:\"jack\",age:\"25\"}],NBA:[{name:\"tom\",sex:\"man\"},{name:\"jack\",sex:\"women\"}]}};";
            String fileName2="myxml.xml";
            buffWri=new BufferedWriter(new FileWriter(fileName2));
            JSONObject jsonObj=new JSONObject(jsonStr);
            buffWri.write("<?xml version=\"1.0\" encoding=\"GBK\"?>");
            buffWri.newLine();
            buffWri.write("<!DOCTYPE properties SYSTEM \"http://java.sun.com/dtd/properties.dtd\">");
            buffWri.newLine();
            buffWri.write(XML.toString(jsonObj));
            buffWri.flush();
            
            System.out.println("run end!");
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            try{
                if(buffRed!=null)
                    buffRed.close();
                if(buffWri!=null)
                    buffWri.close();
            }catch(Exception e){
                e.printStackTrace();
            }
        }
    }
}
xml文件内容：
<?xml version="1.0" encoding="GBK"?> 
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd"> 
<properties> 
<entry key="no">away</entry> 
<entry key="name">HELLO_AWAY</entry> 
</properties> 
输出结果：
JSON str={"properties":{"entry":[{"key":"no","content":"away"},{"key":"name","content":"HELLO_AWAY"}]}}
<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<Heros><NBA><sex>man</sex><name>tom</name></NBA><NBA><sex>women</sex><name>jack</name></NBA><FBI><age>25</age><name>rose</name></FBI><FBI><age>25</age><name>jack</name></FBI></Heros>
4、AJAX中运用JSON
（比使用DOM解析XML简单）
//在响应的程序中输入返回的值：
  out.println("{FBI:[{name:\"rose\",age:\"25\"},{name:\"jack\",age:\"25\"}],NBA:[{name:\"tom\",sex:\"man\"},{name:\"jack\",sex:\"women\"}]}");
//在页面上（点确定页面上会显示jack）
<script language="javascript" src=http://www.mamicode.com/"js/prototype.js"></script>>
5、Java中运用Json
(需要下载json的java开发包)
package callCenterServer;

import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONObject;

public class Test {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception{
        ArrayList<Area> areas=new ArrayList<Area>();
        areas.add(new Test.Area("福建","福州"));
        areas.add(new Test.Area("福建","厦门"));
        areas.add(new Test.Area("福建","泉州"));
        areas.add(new Test.Area("四川","成都"));
        areas.add(new Test.Area("四川","攀枝花"));
        JSONObject jsonObject=new JSONObject();
        for(Test.Area area:areas){
            if(jsonObject.has(area.province)){
                JSONArray jsonArray=(JSONArray)jsonObject.get(area.province);
                jsonArray.put(area.city);
            }else{
                JSONArray jsonArray=new JSONArray();
                jsonArray.put(area.city);
                jsonObject.put(area.province, jsonArray);
            }
        }
        System.out.println(jsonObject);
    }
    
    static class Area{
        private final String province;
        private final String city;
        Area(String province,String city){
            this.province=province;
            this.city=city;
        }
    }
}
输出：{"四川":["成都","攀枝花"],"福建":["福州","厦门","泉州"]}

9.小结

(1)JSON的数据结构只有两种；

(2)可以嵌套表示，比如Array中可以嵌套Object等；

(3)记住：Object是以｛｝表示，Array是以[  ]表示；

------------------------------------整理:Away-----------------------------------------------------