Jsonlib快速上手

Json-lib快速上手

 

JSON是一种很简洁很重要的数据格式，通常用来交换传输数据，广泛使用于JavaScript技术中，并逐渐在各种流行编程语言中火了起来。

 

在Java中也有一个JSON的库，用来重要作用就是Java对象与JSON、XML数据的相互转换，有着重要的应用。

 

开源的JSON库主页：http://json-lib.sourceforge.net/

本开源项目的文档非常好，一下是我看快速起步文档所写，原快速上手文档有一些错误和问题，这里都处理过了。

 

环境：

JDK5

json-lib-2.3-jdk15

 

测试所依赖的包：

json-lib-2.3-jdk15.jar
commons-collections.jar
commons-lang.jar
commons-logging.jar
commons-beanutils.jar
ezmorph-1.0.6.jar
xom-1.1.jar

 

测试代码：

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.xml.XMLSerializer;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
* JSON for Java测试代码
*
* @author leizhimin 2009-12-28 13:15:25
*/
public class TestJSON {
        public static void main(String[] args) {
                test1();
                test2();
                test3();
                test4();
                test5();
        }


        /**
         * 数组或集合-->JSON串
         */
        public static void test1() {
                System.out.println("------------数组或集合-->JSON串----------" );
                boolean [] boolArray = new boolean []{true , false , true };
                JSONArray jsonArray1 = JSONArray.fromObject(boolArray);
                System.out.println(jsonArray1);
//[true,false,true]
                List list = new ArrayList();
                list.add("first" );
                list.add("second" );
                JSONArray jsonArray2 = JSONArray.fromObject(list);
                System.out.println(jsonArray2);
//["first","second"]
                JSONArray jsonArray3 = JSONArray.fromObject("['json','is','easy']" );
                System.out.println(jsonArray3);
// ["json","is","easy"]        
        }

        /**
         * Object|Map-->JSON串
         */
        public static void test2() {
                System.out.println("------------Object|Map-->JSON串----------" );
                Map map = new HashMap();
                map.put("name" , "json" );
                map.put("bool" , Boolean.TRUE);
                map.put("int " , new Integer(1));
                map.put("arr" , new String[]{"a" , "b" });
                map.put("func" , "function(i){ return this .arr[i]; }" );
                JSONObject jsonObject1 = JSONObject.fromObject(map);
                System.out.println(jsonObject1);
//{"func":function(i){ return this.arr[i]; },"arr":["a","b"],"int":1,"bool":true,"name":"json"}

                JSONObject jsonObject2 = JSONObject.fromObject(new MyBean());
                System.out.println(jsonObject2);
//{"func1":function(i){ return this.options[i]; },"func2":function(i){ return this.options[i]; },"name":"json","options":["a","f"],"pojoId":1}
        }

        /**
         * JSON串-->Object
         */
        public static void test3() {
                System.out.println("------------JSON串-->Object----------" );
                String json1 = "{name=/"json/",bool:true ,int :1,double :2.2,func:function(a){ return a; },array:[1,2]}" ;
                JSONObject jsonObject1 = JSONObject.fromObject(json1);
                Object bean1 = JSONObject.toBean(jsonObject1);
                System.out.println(bean1);
//net.sf.ezmorph.bean.MorphDynaBean@10dd1f7[
//    {double=2.2, func=function(a){ return a; }, int=1, name=json, bool=true, array=[1, 2]}
//]
                String json2 = "{bool:true ,integer:1,string:/"json/"}" ;
                JSONObject jsonObject2 = JSONObject.fromObject(json2);
                BeanA bean2 = (BeanA) JSONObject.toBean(jsonObject2, BeanA.class );
                System.out.println(bean2);
// BeanA{bool=true, integer=1, string='json'}
        }

        /**
         * JSON串-->XML
         */
        public static void test4() {
                System.out.println("------------JSON串-->XML----------" );
                JSONObject json = new JSONObject(true );
                String xml = new XMLSerializer().write(json);
                System.out.println(xml);

                JSONObject json1 = JSONObject.fromObject("{/"name/":/"json/",/"bool/":true ,/"int /":1}" );
                String xml1 = new XMLSerializer().write(json1);
                System.out.println(xml1);

                JSONArray json2 = JSONArray.fromObject("[1,2,3]" );
                String xml2 = new XMLSerializer().write(json2);
                System.out.println(xml2);
        }

        /**
         * XML-->JSON串
         */
        public static void test5() {
                System.out.println("------------XML-->JSON串----------" );
                String xml = "" +
                                "<a class =/"array/">/n" +
                                "    <e type=/"function/" params=/"i,j/">/n" +
                                "            return matrix[i][j];/n" +
                                "    </e>/n" +
                                "</a>" ;
                JSONArray json = (JSONArray) new XMLSerializer().read(xml);
                System.out.println(json);
        }
}

 

import net.sf.json.JSONFunction;

/**
* 测试Bean
*
* @author leizhimin 2009-12-28 13:55:09
*/
public class MyBean {
        private String name = "json" ;
        private int pojoId = 1;
        private char [] options = new char []{'a', 'f'};
        private String func1 = "function(i){ return this .options[i]; }" ;
        private JSONFunction func2 = new JSONFunction(new String[]{"i" }, "return this .options[i];" );

        public String getName() {
                return name;
        }

        public void setName(String name) {
                this .name = name;
        }

        public int getPojoId() {
                return pojoId;
        }

        public void setPojoId(int pojoId) {
                this .pojoId = pojoId;
        }

        public char [] getOptions() {
                return options;
        }

        public void setOptions(char [] options) {
                this .options = options;
        }

        public String getFunc1() {
                return func1;
        }

        public void setFunc1(String func1) {
                this .func1 = func1;
        }

        public JSONFunction getFunc2() {
                return func2;
        }

        public void setFunc2(JSONFunction func2) {
                this .func2 = func2;
        }
}

 

/**
* 测试Bean
*
* @author leizhimin 2009-12-28 14:18:18
*/
public class BeanA {
        //                 String json2 = "{bool:true,integer:1,string:/"json/"}";
        private boolean bool;
        private Integer integer;
        private String string;

        public boolean isBool() {
                return bool;
        }

        public void setBool(boolean bool) {
                this .bool = bool;
        }

        public Integer getInteger() {
                return integer;
        }

        public void setInteger(Integer integer) {
                this .integer = integer;
        }

        public String getString() {
                return string;
        }

        public void setString(String string) {
                this .string = string;
        }

        @Override
        public String toString() {
                return "BeanA{" +
                                "bool=" + bool +
                                ", integer=" + integer +
                                ", string='" + string + '/'' +
                                '}';
        }
}

 

运行结果：

------------数组或集合-->JSON串----------
[true ,false ,true ]
["first" ,"second" ]
["json" ,"is" ,"easy" ]
------------Object|Map-->JSON串----------
{"func" :function(i){ return this .arr[i]; },"arr" :["a" ,"b" ],"int " :1,"bool" :true ,"name" :"json" }
{"func1" :function(i){ return this .options[i]; },"func2" :function(i){ return this .options[i]; },"name" :"json" ,"options" :["a" ,"f" ],"pojoId" :1}
------------JSON串-->Object----------
net.sf.ezmorph.bean.MorphDynaBean@bd0108[
    {double =2.2, func=function(a){ return a; }, int =1, name=json, bool=true , array=[1, 2]}
]
BeanA{bool=true , integer=1, string='json'}
------------JSON串-->XML----------
<?xml version="1.0" encoding="UTF-8" ?>
<o null ="true " />

<?xml version="1.0" encoding="UTF-8" ?>
<o><bool type="boolean " >true </bool><int type="number" >1</int ><name type="string" >json</name></o>

<?xml version="1.0" encoding="UTF-8" ?>
<a><e type="number" >1</e><e type="number" >2</e><e type="number" >3</e></a>

------------XML-->JSON串----------
2009-12-28 15:20:39 net.sf.json.xml.XMLSerializer getType
信息: Using default type string
[function(i,j){ return matrix[i][j]; }]

Process finished with exit code 0

 

特别注意：

 

1、所有的Bean都应该定义为public，否则会出现

net.sf.json.JSONException: java.lang.NoSuchMethodException: Property '***' has no getter method

的错误。

 

2、必须引入xom-1.1.jar包，否则抛出

java.lang.NoClassDefFoundError: nu/xom/Serializer

的异常。

 

另外，还有个开源的JSON库，推荐下：

http://code.google.com/p/google-gson/

本文出自 “熔 岩 ” 博客，请务必保留此出处http://lavasoft.blog.51cto.com/62575/251179