json-smart 使用示例(推荐fastjson)

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关于json库，请使用fastjson，这是我用过的最好用的json库！

地址：https://github.com/alibaba/fastjson

=======================================================

json是一种通用的数据格式。相比与protocal buffer、thrift等数据格式，json具有可读性强(文本)、天生具备良好的扩展性(随意增减字段)等优良特点，利用json作为通讯协议，开发效率更高。当然相较于二进制协议，文本更耗带宽。

json和HTTP协议都是基于文本的，天生的一对。面对多终端的未来，使用Json和HTTP作为前端架构的基础将成为开发趋势。

简介

json-smart官方主页：https://code.google.com/p/json-smart/

特性：https://code.google.com/p/json-smart/wiki/FeaturesTests

性能评测：https://code.google.com/p/json-smart/wiki/Benchmark

Json-smart-API: http://www.jarvana.com/jarvana/view/net/minidev/json-smart/1.0.9/json-smart-1.0.9-javadoc.jar!/net/minidev/json/package-summary.html

javadoc: https://github.com/u2waremanager/maven-repository/blob/master/net/minidev/json-smart/1.1.1/json-smart-1.1.1-javadoc.jar

使用示例

import net.minidev.json.JSONObject;

import net.minidev.json.JSONValue;

import net.minidev.json.JSONArray;

import net.minidev.json.JSONStyle;

import net.minidev.json.parser.ParseException;

import java.io.UnsupportedEncodingException;

import java.util.*;

/*

 * Home page: http://code.google.com/p/json-smart/

 *

 * compiler:  javac -cp json-smart-1.1.1.jar JsonSmartTest.java

 *

 * Run:       java -cp ./:json-smart-1.1.1.jar JsonSmartTest

 *

 */

public class JsonSmartTest {

    //1. String <==> JsonObject

    public static void DecodingTest() throws ParseException {

        System.out.println("=======decode=======");

        String s="[0,{'1':{'2':{'3':{'4':[5,{'6':7}]}}}}]";

        Object obj=JSONValue.parse(s);

        JSONArray array=(JSONArray)obj;

        System.out.println("======the 2nd element of array======");

        System.out.println(array.get(1));

        System.out.println();

        JSONObject obj2=(JSONObject)array.get(1);

        System.out.println("======field \"1\"==========");

        System.out.println(obj2.get("1"));

        s="{}";

        obj=JSONValue.parse(s);

        System.out.println(obj);                

        s="{\"key\":\"Value\"}";

        // JSONValue.parseStrict()

        // can be use to be sure that the input is wellformed

        obj=JSONValue.parseStrict(s);

        JSONObject obj3=(JSONObject)obj;

        System.out.println("====== Object content ======");

        System.out.println(obj3.get("key"));

        System.out.println();

    }

    public static void EncodingTest() {

        System.out.println("=======EncodingTest=======");

        // Json Object is an HashMap<String, Object> extends

        JSONObject obj = new JSONObject();

        obj.put("name", "foo");

        obj.put("num", 100);

        obj.put("balance", 1000.21);

        obj.put("is_vip", true);

        obj.put("nickname",null);

        System.out.println("Standard RFC4627 JSON");

        System.out.println(obj.toJSONString());

        System.out.println("Compacted JSON Value");

        System.out.println(obj.toJSONString(JSONStyle.MAX_COMPRESS));

        // if obj is an common map you can use:

        System.out.println("Standard RFC4627 JSON");

        System.out.println(JSONValue.toJSONString(obj));

        System.out.println("Compacted JSON Value");

        System.out.println(JSONValue.toJSONString(obj, JSONStyle.MAX_COMPRESS));   

    }

    public static void EncodingTest2() {

        System.out.println("=======EncodingTest2=======");

        // Json Object is an HashMap<String, Object> extends

        JSONObject obj = new JSONObject();

        obj.put("name", "foo");

        obj.put("num", 100);

        obj.put("balance", 1000.21);

        obj.put("is_vip", true);

        obj.put("nickname",null);

        //Output Compressed json

        Object value = obj;

        String com_json = JSONValue.toJSONString(value, JSONStyle.MAX_COMPRESS);

        String json = JSONValue.toJSONString(value, JSONStyle.NO_COMPRESS);

        System.out.println("Compacted JSON Value");

        System.out.println(com_json);

        System.out.println("From RFC4627 JSON String: " + JSONValue.compress(json));

        System.out.println("From Compacted JSON String: " + JSONValue.compress(com_json));

        System.out.println("Standard RFC4627 JSON Value");

        System.out.println(json);

        System.out.println("From RFC4627 JSON String: " + JSONValue.uncompress(json));

        System.out.println("From Compacted JSON String: " + JSONValue.uncompress(com_json));

        //from compress json string

        System.out.println("From compress json string(JSONObject)");

        Object obj2=JSONValue.parse(com_json);

        System.out.println(JSONValue.toJSONString(obj2, JSONStyle.NO_COMPRESS));

        System.out.println(JSONValue.toJSONString(obj2, JSONStyle.MAX_COMPRESS));

    }

    //2. Java Struct <==> JsonSmart object

    public class Person {

        String  name;

        int     age;

        boolean single;

        long    mobile;

        public String getName(){

            return this.name;

        }

        public void setName(String name) {

            this.name = name;

        }

        public int getAge() {

            return this.age;

        }

        public void setAge(int age) {

            this.age = age;

        }

        public boolean getSingle() {

            return this.single;

        }

        public void setSingle(boolean single) {

            this.single = single;

        }

        public long getMobile() {

            return mobile;

        }

        public void setMobile(long mobile) {

            this.mobile = mobile;

        }

    }

    public class JSONDomain {    // for convert struct <==> json

        public Object result = new JSONObject();

        public Object getResult() {

            return result;

        }

        public void setResult(Object result) {

            this.result = result;

        }

    }

    public void Struct2JsonObject() {

        System.out.println("========Struct2JsonObject=======");

        Person person = new Person();

        person.setName("json smart");

        person.setAge(13);

        person.setMobile(20130808);

        Person person2 = new Person();

        person2.setName("test");

        person2.setAge(123);

        person2.setMobile(888666);

        List<Person> array = new ArrayList<Person>();

        array.add(person);

        array.add(person2);

        //1. struct <==> JsonObject

        JSONObject obj = new JSONObject();

        //obj = (Object)person;  // compiler error!

        // way 1:

        JSONDomain data = new JSONDomain();   // for convert

        data.setResult(person);

        // obj = (JSONObject)data.getResult(); // run error: ClassCastException

        obj.put("person", data.getResult());

        System.out.println(JSONValue.toJSONString(obj));

        // way 2:

        obj.put("person", array.get(1));

        System.out.println(JSONValue.toJSONString(obj));

        //2. Container <==> JsonObject

        JSONArray jsonArray = new JSONArray();

        jsonArray.add(person);

        jsonArray.add(person2);

        JSONObject result = new JSONObject();

        result.put("persons", jsonArray);

        System.out.println(JSONValue.toJSONString(result));

    }

    //3. JsonSmartSerializationTest

    public static Map<String, Object> testBytes2Map(byte[] bytes) {

        Map<String, Object> map = null;

        try {

            map = (Map<String, Object>) JSONValue.parseStrict((new String(bytes, "UTF-8")));

        } catch (ParseException e) {

            e.printStackTrace();

        } catch (UnsupportedEncodingException e) {

            e.printStackTrace();

        }

        return map;

    }

    // JsonSmartSerializationTest

    public static byte[] testMap2Bytes(Map<String, Object> map) {

        String str = JSONObject.toJSONString(map);

        byte[] result = null;

        try {

            result = str.getBytes("UTF-8");

        } catch (UnsupportedEncodingException e) {

            e.printStackTrace();

        }

        return result;

    }

    public static void main(String[] args) throws Exception {

        DecodingTest();

        EncodingTest();

        EncodingTest2();

        JsonSmartTest test = new JsonSmartTest();

        test.Struct2JsonObject();

    }

}

解析文件示例

import net.minidev.json.JSONObject;

import net.minidev.json.JSONValue;

import net.minidev.json.JSONArray;

import net.minidev.json.JSONStyle;

import net.minidev.json.parser.ParseException;

import java.io.UnsupportedEncodingException;

import java.util.*;

import java.lang.StringBuffer;

import java.io.File;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.IOException;

/*

 * Home page: http://code.google.com/p/json-smart/

 *

 * compiler:  javac -cp json-smart-1.1.1.jar JsonTool.java

 *

 * Run:       java -cp ./:json-smart-1.1.1.jar JsonTool

 *

 */

public class JsonTool {

    //1. String <==> JsonObject

    public static void ParseData(String data) throws ParseException {

        System.out.println("=======decode=======");

        // s="{\"key\":\"Value\"}";

        Object obj  = JSONValue.parseStrict(data);

        JSONObject obj3 = (JSONObject)obj;

        System.out.println(obj3.get("data"));

        System.out.println();

    }

    public static void EncodingTest() {

        System.out.println("=======EncodingTest=======");

        // Json Object is an HashMap<String, Object> extends

        JSONObject obj = new JSONObject();

        obj.put("name", "foo");

        obj.put("num", 100);

        obj.put("balance", 1000.21);

        obj.put("is_vip", true);

        obj.put("nickname",null);

        System.out.println("Standard RFC4627 JSON");

        System.out.println(obj.toJSONString());

        System.out.println("Compacted JSON Value");

        System.out.println(obj.toJSONString(JSONStyle.MAX_COMPRESS));

        // if obj is an common map you can use:

        System.out.println("Standard RFC4627 JSON");

        System.out.println(JSONValue.toJSONString(obj));

        System.out.println("Compacted JSON Value");

        System.out.println(JSONValue.toJSONString(obj, JSONStyle.MAX_COMPRESS));   

    }

    public static void main(String[] args) throws Exception {

        if( args.length < 1) {

                System.out.println("Usage: JsonTool file");

                System.exit(-1);

        }

        String file = args[0];

        System.out.println(file);

        StringBuffer strBuffer = new StringBuffer();

        InputStreamReader inputReader = null;

        BufferedReader bufferReader = null;

        OutputStream outputStream = null;

        try

        {

            InputStream inputStream = new FileInputStream(file);

            inputReader = new InputStreamReader(inputStream);

            bufferReader = new BufferedReader(inputReader);

            // 读取一行

            String line = null;

            while ((line = bufferReader.readLine()) != null)

            {

                strBuffer.append(line);

            } 

        }

        catch (IOException e)

        {

            System.out.println(e.getMessage());

        }

        finally

        {

            // OtherUtilAPI.closeAll(outputStream, bufferReader, inputReader);

        }

        //System.out.println(strBuffer.toString());

        //System.out.println("\n");

        ParseData(strBuffer.toString());

    }

}