代码改变世界

json-smart 使用示例(推荐fastjson)

2013-08-08 10:44 by zhenjing, ... 阅读, ... 评论, 收藏, 编辑

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());
    }
}

参考

Java序列化与JSON序列化大比拼

Java序列化与JSON序列化大比拼2

多终端的前端架构选择