Json-path學(xué)習(xí)筆記<二>

Soarkey 發(fā)布于2019-08-14 12:35 / 931人閱讀

摘要：該篇主要以代碼示例為主，因?yàn)樯喜蝗?，看不到這個(gè)官方文檔和。因?yàn)榻酉聛淼牡讓幽J(rèn)使用的就是。和功能是一致的。區(qū)別是不會(huì)拋出異常，而會(huì)拋出異常。而解析輸入的文本內(nèi)容依據(jù)默認(rèn)的解析文本的模式。

Json-smart

該篇主要以代碼示例為主，因?yàn)間oogle上不去，看不到Json-smart這個(gè)官方文檔和API。故只例舉一些代碼示例。因?yàn)榻酉聛淼腏son-path底層默認(rèn)使用的就是JsonSmart。JsonSmart的源碼并不多，有興趣可以去看看

解析簡單json格式的字符串

import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;
import net.minidev.json.JSONValue;

public class ParseJsonString {

    public static void main(String[] args) {
        /**
         *          * [
         *       0,
         *       {
         *           "1": {
         *               "2": {
         *                   "3": {
         *                       "4": [
         *                           5,
         *                           {
         *                               "6": 7
         *                           }
         *                       ]
         *                   }
         *               }
         *           }
         *       }
         *   ]
         * 
         * */
        String str="[0,{"1":{"2":{"3":{"4":[5,{"6":7}]}}}}]";
        if (JSONValue.isValidJson(str)) { //判斷是否是合法的json字符串
            Object obj=JSONValue.parse(str);
            JSONArray array=(JSONArray)obj;
            System.out.println(array.size());
            System.out.println(array);
            JSONObject jsonObject = (JSONObject) array.get(1);
            System.out.println(jsonObject);
            JSONObject jsonObject1 = (JSONObject) jsonObject.get("1");
            System.out.println(jsonObject1.toJSONString());
            JSONObject jsonObject2 = (JSONObject) jsonObject1.get("2");
            System.out.println(jsonObject2.toJSONString());
            JSONObject jsonObject3 = (JSONObject) jsonObject2.get("3");
            System.out.println(jsonObject3.toJSONString());
            JSONArray array2 =  (JSONArray) jsonObject3.get("4");
            System.out.println(array2);
            JSONObject jsonObject4 = (JSONObject) array2.get(1);
            System.out.println(jsonObject4.toJSONString());
            int data = Integer.parseInt(jsonObject4.get("6").toString());
            System.out.println(data);
        }
    }
}

輸出：

2
[0,{"1":{"2":{"3":{"4":[5,{"6":7}]}}}}]
{"1":{"2":{"3":{"4":[5,{"6":7}]}}}}
{"2":{"3":{"4":[5,{"6":7}]}}}
{"3":{"4":[5,{"6":7}]}}
{"4":[5,{"6":7}]}
[5,{"6":7}]
{"6":7}
7

JSONValue的使用

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import net.minidev.json.JSONObject;
import net.minidev.json.JSONStyle;
import net.minidev.json.JSONValue;
import net.minidev.json.parser.ParseException;

public class JsonValueTest {
    public static void main(String[] args) throws ParseException, IOException {
        // public class JSONObject extends HashMap 
        //              implements JSONAware, JSONAwareEx, JSONStreamAwareEx {}
        JSONObject obj = new JSONObject();
        obj.put("name", "foo");
        obj.put("num", 100);
        obj.put("balance", 1000.21);
        obj.put("is_vip", true);
        obj.put("is_special_fuhao", """);
        obj.put("nickname", null);
        // 判斷是否是合法的json串
        System.out.println(JSONValue.isValidJson(obj.toJSONString()));
        // 轉(zhuǎn)義 quotes, , /, 
, 
, , f, 	 and other control characters (U+0000 through U+001F).
        System.out.println(JSONValue.escape(obj.toJSONString()));
        System.out.println(obj.toJSONString());
        System.out.println(JSONValue.toJSONString(obj));
        // JSONStyle object configure JSonSerializer reducing output size
        System.out.println(obj.toJSONString(JSONStyle.NO_COMPRESS));
        System.out.println(obj.toJSONString(JSONStyle.MAX_COMPRESS));
        System.out.println(JSONValue.toJSONString(obj, JSONStyle.MAX_COMPRESS));
        System.out.println(JSONValue.compress(obj.toJSONString()));
        System.out.println(JSONValue.uncompress(obj.toJSONString()));
        System.out.println(JSONValue.uncompress(JSONValue.toJSONString(obj, JSONStyle.MAX_COMPRESS)));
        // Parse Json input to a java Object keeping element order
        System.out.println(JSONValue.parseKeepingOrder(obj.toJSONString()));
        // 解析字符串的時(shí)候會(huì)拋異常 throw ParseException
        System.out.println(JSONValue.parseWithException(obj.toJSONString()));
        System.out.println("**********************************");
        String str="{"key":"Value"}";
        Object obj1=JSONValue.parse(str);
        System.out.println(obj1); 
        obj1=JSONValue.parseStrict(str);
        System.out.println(obj1); 
        JSONObject obj2=(JSONObject)obj1;
        System.out.println(obj2.get("key"));
        System.out.println("**********************************");
        StringBuffer strBuffer = new StringBuffer("zhangsan");
        Map map = new HashMap();
        map.put("hello", "world");
        map.put("hello1", "world1");
        map.put("hello2", "world2");
        JSONValue.writeJSONString(map, strBuffer, JSONStyle.NO_COMPRESS);
//        JSONValue.writeJSONString(map, strBuffer, JSONStyle.MAX_COMPRESS);
//        如果設(shè)置JSONStyle.MAX_COMPRESS，那么strBuffer輸出： zhangsan{hello:world,hello2:world2,hello1:world1}
        System.out.println(strBuffer);
    }
}

輸出：

true
{"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{balance:1000.21,num:100,is_vip:true,name:foo,is_special_fuhao:"""}
{balance:1000.21,num:100,is_vip:true,name:foo,is_special_fuhao:"""}
{balance:1000.21,num:100,nickname:null,is_vip:true,name:foo,is_special_fuhao:"""}
{"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{"balance":1000.21,"num":100,"is_vip":true,"name":"foo","is_special_fuhao":"""}
{balance=1000.21, num=100, nickname=null, is_vip=true, name=foo, is_special_fuhao="}
{"balance":1000.21,"num":100,"is_vip":true,"nickname":null,"name":"foo","is_special_fuhao":"""}
**********************************
{"key":"Value"}
{"key":"Value"}
Value
**********************************
zhangsan{"hello":"world","hello2":"world2","hello1":"world1"}

JSONValue中所有的parse方法內(nèi)部都是調(diào)用JSONParser實(shí)現(xiàn)的parse的方法。

JSONValue.parse() 和 JSONValue.parseStrict() 功能是一致的。區(qū)別是JSONValue.parse()不會(huì)拋出異常，而JSONValue.parseStrict()會(huì)拋出ParseException異常。

JSONValue.parseStrict()和JSONValue.parseWithException() 都會(huì)拋出ParseException異常，單從輸出結(jié)果看二者是一樣的，區(qū)別是JSONValue.parseStrict()的解析輸入的json文本的有效性是依據(jù)RFC4627。而JSONValue.parseWithException()解析輸入的json文本內(nèi)容依據(jù)默認(rèn)的解析文本的模式。

JsonValue的remapField方法以及對于編碼轉(zhuǎn)換

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.StringReader;

import net.minidev.json.JSONObject;
import net.minidev.json.JSONValue;
import net.minidev.json.writer.JsonReader;


public class JsonReaderTest {

    static String[] nonLatinTexts = new String[] { "????? ?????", "日本語", "Русский", "?????", "???", "???????", "??????", "?????", "中文", "????", "??????", "??????", "?????????" };
    public static void main(String[] args) throws IOException {
        String text = "{"new":"foo","default":"bar"}";
        JSONValue.remapField(TRen.class, "default", "default_");
        JSONValue.remapField(TRen.class, "new", "new_");
        TRen t = JSONValue.parse(text, TRen.class);
        System.out.println(JSONValue.toJSONString(t));
        System.out.println("*******************************");
        for (String nonLatinText : nonLatinTexts) {
            String s = "{"key":"" + nonLatinText + ""}";
//            1. StringReader reader = new StringReader(s);
//               JSONObject obj = (JSONObject) JSONValue.parse(reader);
//            2. ByteArrayInputStream bis = new ByteArrayInputStream(s.getBytes("utf8"));
//               JSONObject obj = (JSONObject) JSONValue.parse(bis);
//            3. byte[] bs = s.getBytes("utf8");
//               JSONObject obj = (JSONObject) JSONValue.parse(bs);
            JSONObject obj = (JSONObject) JSONValue.parse(s);
            String v = (String) obj.get("key"); // result is incorrect
            System.out.print(v + ", ");
        }
        System.out.println();
    }
    public static class TRen {
        public String new_;
        public String default_;
    }
}

輸出

{"default":"bar","new":"foo"}
*******************************
????? ?????, 日本語, Русский, ?????, ???, ???????, ??????, ?????, 中文, ????, ??????, ??????, ?????????,

Json轉(zhuǎn)Object示例

import java.util.ArrayList;
import java.util.List;

import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;
import net.minidev.json.JSONValue;

public class JsonToObject {
    public static void main(String[] args) {
        People people = new People();
        people.setName("test1");
        people.setAge(13);
        people.setMobile(20130808);

        People people1 = new People();
        people1.setName("test");
        people1.setAge(123);
        people1.setMobile(888666);

        List array = new ArrayList();
        array.add(people);
        array.add(people1);
        JSONObject obj = new JSONObject();
        obj.put("peoples", array);
        System.out.println(JSONValue.toJSONString(obj));
        JSONArray jsonArray = new JSONArray();
        jsonArray.add(people);
        jsonArray.add(people1);
        JSONObject result = new JSONObject();
        result.put("peoples", jsonArray);
        System.out.println(JSONValue.toJSONString(result));
    }
}

class People {
    public String name;
    public int age;
    public boolean single;
    public long mobile;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public boolean isSingle() {
        return single;
    }
    public void setSingle(boolean single) {
        this.single = single;
    }
    public long getMobile() {
        return mobile;
    }
    public void setMobile(long mobile) {
        this.mobile = mobile;
    }
}

輸出：

{"peoples":[{"single":false,"age":13,"name":"test1","mobile":20130808},{"single":false,"age":123,"name":"test","mobile":888666}]}
{"peoples":[{"single":false,"age":13,"name":"test1","mobile":20130808},{"single":false,"age":123,"name":"test","mobile":888666}]}

參考文檔：
Json-smart在gitHub上的代碼
JsonSmart文檔