1.可以利用Android API中的JsonReader解析Json數(shù)據(jù)

2.可以引入Gson的jar包，結(jié)合JavaBean解析Json數(shù)據(jù)

Bean.java

package com.sphere.json;public class Bean {    /**     * Bean中的數(shù)據(jù)必須與Json數(shù)據(jù)中的key鍵值     * 一一對(duì)應(yīng)  名字不可更改、     * name 與json的name鍵值對(duì)應(yīng)     * wife 與json數(shù)據(jù)中的wife對(duì)應(yīng)     * 否則會(huì)出現(xiàn)讀取為null的現(xiàn)象     */    PRivate String name;    private String wife;        public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getWife() {        return wife;    }    public void setWife(String wife) {        this.wife = wife;    }        }

Gson解析工具類

package com.sphere.json;import java.io.IOException;import java.io.StringReader;import java.lang.reflect.Type;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.LinkedList;import com.google.gson.Gson;import com.google.gson.reflect.TypeToken;import com.google.gson.stream.JsonReader;public class JsonUtils {    /**     * 使用JsonReader     * @param data     */    public void parseJson(String data){        try {            //創(chuàng)建JsonReader對(duì)象            JsonReader reader = new JsonReader(new StringReader(data));            //開始解析數(shù)組            reader.beginArray();            while(reader.hasNext()){                //開始解析對(duì)象                reader.beginObject();                while(reader.hasNext()){                    //得到鍵                    String tagName = reader.nextName();                    if(tagName.equals("name")){                        System.out.print("name --->"+reader.nextString());                    }                    else if(tagName.equals("wife")){                        System.out.println("    wife --->"+reader.nextString());                    }                }                //解析對(duì)象結(jié)束                reader.endObject();            }            //解析數(shù)組結(jié)束            reader.endArray();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }        //解析json數(shù)組  返回list對(duì)象    public ArrayList<HashMap<String, String>> parseBeanFromJson(String jsonArray){                //Gson解析Json數(shù)組        Type type = new TypeToken<LinkedList<Bean>>(){}.getType();        Gson gson = new Gson();        LinkedList<Bean> beans = gson.fromJson(jsonArray, type);                        ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();        for (Iterator iterator = beans.iterator(); iterator.hasNext();) {            Bean bean = (Bean) iterator.next();            //System.out.print(bean.getName());            //System.out.println(bean.getWife());                        HashMap<String, String> map = new HashMap<String, String>();            map.put("name", bean.getName());            map.put("wife", bean.getWife());            /*添加到list中*/            list.add(map);        }                /*遍歷list*/        int index = 0;        for (Iterator iterator = list.iterator(); iterator.hasNext();) {            HashMap<String, String> hashMap = (HashMap<String, String>) iterator.next();            System.out.println("list中第"+(++index)+"個(gè)元素"+hashMap);        }                return list;    }}

測(cè)試類Test.java

package com.sphere.json;import com.google.gson.Gson;public class Test {        static String jsonArray = "[{/"name/":/"張無忌/",/"wife/":/"敏敏特穆爾/"},{/"name/":/"楊過/",/"wife/":/"小龍女/"}]";        static String jsonData = "{/"name/":/"張無忌/",/"wife/":/"敏敏特穆爾/"}";            public static void main(String[] args) {        new JsonUtils().parseJson(jsonArray);        System.out.println();                /**********解析Json數(shù)據(jù)***********/        Gson gson = new Gson();        Bean user = gson.fromJson(jsonData, Bean.class);        System.out.println("我叫"+user.getName()+" 我妻子是"+user.getWife());        System.out.println();                /**********解析Json數(shù)組***********/        new JsonUtils().parseBeanFromJson(jsonArray);    }}

輸出結(jié)果：

name --->張無忌    wife --->敏敏特穆爾name --->楊過    wife --->小龍女我叫張無忌 我妻子是敏敏特穆爾list中第1個(gè)元素{wife=敏敏特穆爾, name=張無忌}list中第2個(gè)元素{wife=小龍女, name=楊過}

假設(shè)我想跟蹤代碼查看某個(gè)gson中函數(shù)的具體實(shí)現(xiàn)，該如何添加對(duì)源碼信息的查看呢。

其實(shí)很簡(jiǎn)單， 我們先下載gson-2.2.4-sources.jar這個(gè)jar包，將其拷貝到libs目錄下。

我們?cè)诖a中使用ctrl + 左鍵 ，點(diǎn)擊某個(gè)gson的API函數(shù)，如下，我們查看JsonReader這個(gè)函數(shù)

eclipse跳轉(zhuǎn)到.class 頁面

我們點(diǎn)擊箭頭所指的按鈕attch source, 如下圖：

因?yàn)槲覀儼裺ource.jar拷貝到了工程目錄下 所以這里選擇workspace

選中源碼的jar

點(diǎn)擊確定，就可以在eclipse中查看追蹤gson的源碼了。

//------------------------------------------------------------------------------------

　　以下關(guān)于gson基本用法示例來自http://www.survivalescaperooms.com/kunpengit/p/4001680.html

//-------------------------------------------------------------------------------------

(3)bean轉(zhuǎn)換json

Gson gson = new Gson();String json = gson.toJson(obj);obj是對(duì)象

(4)json轉(zhuǎn)換bean

Gson gson = new Gson();

String json = "{/"id/":/"2/",/"name/":/"Json技術(shù)/"}";Book book = gson.fromJson(json, Book.class);

(5)json轉(zhuǎn)換復(fù)雜的bean，比如List，Set將json轉(zhuǎn)換成復(fù)雜類型的bean,需要使用TypeTokenGson gson = new Gson();String json = "[{/"id/":/"1/",/"name/":/"Json技術(shù)/"},{/"id/":/"2/",/"name/":/"java技術(shù)/"}]";//將json轉(zhuǎn)換成ListList list = gson.fromJson(json,new TypeToken<LIST>() {}.getType());//將json轉(zhuǎn)換成SetSet set = gson.fromJson(json,new TypeToken<SET>() {}.getType());

(6)通過json對(duì)象直接操作json以及一些json的工具a)格式化JsonString json = "[{/"id/":/"1/",/"name/":/"Json技術(shù)/"},{/"id/":/"2/",/"name/":/"java技術(shù)/"}]";Gson gson = new GsonBuilder().setPrettyPrinting().create();JsonParser jp = new JsonParser();JsonElement je = jp.parse(json);json = gson.toJson(je);b)判斷字符串是否是json,通過捕捉的異常來判斷是否是jsonString json = "[{/"id/":/"1/",/"name/":/"Json技術(shù)/"},{/"id/":/"2/",/"name/":/"java技術(shù)/"}]";boolean jsonFlag;try {new JsonParser().parse(str).getAsJsonObject();jsonFlag = true;} catch (Exception e) {jsonFlag = false;}

c)從json串中獲取屬性String json = "{/"id/":/"1/",/"name/":/"Json技術(shù)/"}";String propertyName = 'id';String propertyValue = "";try {JsonParser jsonParser = new JsonParser();JsonElement element = jsonParser.parse(json);JsonObject jsonObj = element.getAsJsonObject();propertyValue = jsonObj.get(propertyName).toString();} catch (Exception e) {propertyValue = null;}

d)除去json中的某個(gè)屬性String json = "{/"id/":/"1/",/"name/":/"Json技術(shù)/"}";String propertyName = 'id';JsonParser jsonParser = new JsonParser();JsonElement element = jsonParser.parse(json);JsonObject jsonObj = element.getAsJsonObject();jsonObj.remove(propertyName);json = jsonObj.toString();

e)向json中添加屬性String json = "{/"id/":/"1/",/"name/":/"Json技術(shù)/"}";String propertyName = 'desc';Object propertyValue = "json各種技術(shù)的調(diào)研";JsonParser jsonParser = new JsonParser();JsonElement element = jsonParser.parse(json);JsonObject jsonObj = element.getAsJsonObject();jsonObj.addProperty(propertyName, new Gson().toJson(propertyValue));json = jsonObj.toString();

f)修改json中的屬性String json = "{/"id/":/"1/",/"name/":/"Json技術(shù)/"}";String propertyName = 'name';Object propertyValue = "json各種技術(shù)的調(diào)研";JsonParser jsonParser = new JsonParser();JsonElement element = jsonParser.parse(json);JsonObject jsonObj = element.getAsJsonObject();jsonObj.remove(propertyName);jsonObj.addProperty(propertyName, new Gson().toJson(propertyValue));json = jsonObj.toString();

g)判斷json中是否有屬性String json = "{/"id/":/"1/",/"name/":/"Json技術(shù)/"}";String propertyName = 'name';boolean isContains = false ;JsonParser jsonParser = new JsonParser();JsonElement element = jsonParser.parse(json);JsonObject jsonObj = element.getAsJsonObject();isContains = jsonObj.has(propertyName);

h)json中日期格式的處理GsonBuilder builder = new GsonBuilder();builder.setDateFormat("yyyy-MM-dd HH:mm:ss.SSS");Gson gson = builder.create();然后使用gson對(duì)象進(jìn)行json的處理，如果出現(xiàn)日期Date類的對(duì)象，就會(huì)按照設(shè)置的格式進(jìn)行處理

i)json中對(duì)于Html的轉(zhuǎn)義Gson gson = new Gson();這種對(duì)象默認(rèn)對(duì)Html進(jìn)行轉(zhuǎn)義，如果不想轉(zhuǎn)義使用下面的方法GsonBuilder builder = new GsonBuilder();builder.disableHtmlEscaping();Gson gson = builder.create();