android json教程,Android之JSON解析
编写项目，包含一个Activity。Activity页面效果如下图所示。点击按钮“解析文件1”后解析Json文件json_single并将结果显示在红色框体中，点击按钮“解析文件2”后解析Json文件json_multiple并将结果显示在红色框体中(有多条数据，建议使用列表控件ListView进行信息展示)。
先写xml布局文件
1
2
3 android:layout_width="match_parent"
4 android:layout_height="match_parent"
5 android:orientation="vertical">
6
7
8 android:id="@+id/button50"
9 android:layout_width="match_parent"
10 android:layout_height="wrap_content"
11
12 android:text="解析文件1" />
13
14 android:id="@+id/button51"
15 android:layout_width="match_parent"
16 android:layout_height="wrap_content"
17 android:text="解析文件2" />
18
19 android:layout_width="match_parent"
20 android:layout_height="wrap_content"
21 android:id="@+id/LS"/>
22
将我们的JSON文件导入到res的raw下，如果没有raw，右键Andrriod Resource Directory在Resource type中输入raw,ok
json_single.json :
1 {
2 "name":"王小二",
3 "age":25,
4 "birthday":"1990-01-01",
5 "school":"师大",
6 "car":"比亚迪",
7 "house":"宿舍",
8 }
json_multiple.json :
1 [{
2 "name":"王小二",
3 "age":25,
4 "birthday":"1990-01-01",
5 "school":"师大",
6 "car":"比亚迪",
7 "house":"宿舍",
8 },
9 {
10 "name":"李三",
11 "age":30,
12 "birthday":"1987-04-13",
13 "school":"清华",
14 "car":"大众速腾",
15 "house":"公寓",
16 },
17 {
18 "name":"张盼盼",
19 "age":17,
20 "birthday":"1995-07-02",
21 "school":"北大",
22 "car":"宝马7系",
23 "house":"别墅",
24 }]
思路很简单，就是读取到json文件然后解析最后显示出来。
Mainactiviyt ：
1 package com.example.app;
2
3 import androidx.annotation.RequiresApi;
4 import androidx.appcompat.app.AppCompatActivity;
5
6 import android.Manifest;
7 import android.annotation.SuppressLint;
8 import android.os.Build;
9 import android.os.Bundle;
10 import android.view.View;
11 import android.view.ViewGroup;
12 import android.view.LayoutInflater;
13
14 import android.widget.*;
15 import org.json.*;
16 import org.json.JSONException;
17 import org.json.JSONObject;
18 import java.io.BufferedReader;
19 import java.io.FileOutputStream;
20 import java.io.FileInputStream;
21 import java.io.IOException;
22 import java.io.InputStream;
23 import java.io.InputStreamReader;
24 import java.security.Permission;
25 import java.security.Permissions;
26 import java.io.UnsupportedEncodingException;
27
28
29 public class MainActivity extends AppCompatActivity {
30
31 private static String[] Json; //用来存储的数组
32 private ListView LS;
33 private Button B1;
34 private Button B2;
35 private int a = 0;
36
37 @Override
38 protected void onCreate(Bundle savedInstanceState) {
39 super.onCreate(savedInstanceState);
40 setContentView(R.layout.homework_8_2);
41
42 B1 = (Button) findViewById(R.id.button50);
43 B2 = (Button) findViewById(R.id.button51);
44 LS = (ListView) findViewById(R.id.LS); //实例化按钮B1,B2,和listview
45 B1.setOnClickListener(new View.OnClickListener() {//监听B1
46 @Override
47 public void onClick(View v) {
48 //Json = new String[100];
49 JsonDataToString1(); //读取json文件
50 }
51 });
52 B2.setOnClickListener(new View.OnClickListener() {//监听B2
53 @Override
54 public void onClick(View v) {
55 //Json = new String[100];
56 a = 0; //当B2被点击，变量a就会重置为0
57 JsonDataToString2(); //读取json文件
58 }
59 });
60 }
61 @SuppressLint("ResourceType")
62 private void JsonDataToString1(){
63
64 InputStreamReader inputStreamReader = null;
65 String jsonData = "";
66 try {
67 inputStreamReader = new InputStreamReader(getResources().openRawResource(R.raw.json_single),"UTF-8");//读取
68 BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
69 String line;
70 StringBuilder srt = new StringBuilder();
71 while((line = bufferedReader.readLine()) != null){
72 srt.append(line);
73 }
74 inputStreamReader.close();
75 bufferedReader.close();
76 jsonData = srt.toString(); //以上就是读取json文件，转化成string
77 }catch (UnsupportedOperationException e){
78 e.printStackTrace();
79 }catch (IOException e){
80 e.printStackTrace();
81 }
82
83 if (jsonData != ""){
84 getDataFromData1(jsonData); //进一步分析字符串，获取json内容
85 }else {
86 Toast.makeText(MainActivity.this,"error",Toast.LENGTH_SHORT).show();
87 }
88 }
89
90 private void getDataFromData1(String jsonData){
91 try{
92
93 JSONObject jsonObject = new JSONObject(jsonData);
94 String name = jsonObject.getString("name");
95 String age = jsonObject.getString("age");
96 String birthday = jsonObject.getString("birthday");
97 String school = jsonObject.getString("school");
98 String car = jsonObject.getString("car");
99 String house = jsonObject.getString("house"); //获取json内容
100 Json = new String[]{
101 "name:"+name,"age:"+age,"birthday:"+birthday,"school:"+school,"car:"+car,"house:"+house
102 };//将json内容存进数组中
103 ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,R.id.LS);//新建并配置ArrayAapeter
104 MyBaseAdapter mAdapter = new MyBaseAdapter();
105 LS.setAdapter(mAdapter);
106 }catch (JSONException e){
107 e.printStackTrace();
108 }
109 }
110
111 @SuppressLint("ResourceType")
112 private void JsonDataToString2(){
113
114 InputStreamReader inputStreamReader = null;
115 String jsonData = "";
116 try {
117 inputStreamReader = new InputStreamReader(getResources().openRawResource(R.raw.json_multiple),"UTF-8");//读取
118 BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
119 String line;
120 StringBuilder srt = new StringBuilder();
121 while((line = bufferedReader.readLine()) != null){
122 srt.append(line);
123 }
124 inputStreamReader.close();
125 bufferedReader.close();
126 jsonData = srt.toString();//以上就是读取json文件，转化成string
127 }catch (UnsupportedOperationException e){
128 e.printStackTrace();
129 }catch (IOException e){
130 e.printStackTrace();
131 }
132
133 if (jsonData != ""){
134 getDataFromData2(jsonData); //进一步分析字符串，获取json内容
135 }else {
136 Toast.makeText(MainActivity.this,"error",Toast.LENGTH_SHORT).show();
137 }
138 }
139
140 private void getDataFromData2(String jsonData){
141 try{
142 Json = new String[100]; //这里必须初始化Json数组，否则点击完解析一后Json数组的length只有6，会因空间不足而程序崩溃
143 JSONArray jsonArray = new JSONArray(jsonData);
144 //String[] bbk = new String[]{};
145 for (int i=0;i
146 JSONObject jsonObject = jsonArray.getJSONObject(i);
147 String name = jsonObject.getString("name");
148 String age = jsonObject.getString("age");
149 String birthday = jsonObject.getString("birthday");
150 String school = jsonObject.getString("school");
151 String car = jsonObject.getString("car");
152 String house = jsonObject.getString("house");//解析出json的内容
153 Json[a] = "name:"+name; //为了将数据循环存储进Json数组中，用了一个变量a来控制
154 Json[a+1] = "age:"+age;
155 Json[a+2] = "birthday:"+birthday;
156 Json[a+3] = "school:"+school;
157 Json[a+4] = "car:"+car;
158 Json[a+5] = "house:"+house; //因为发现数据有六项且key值都一样，就正好用一个变量a来表示数组的下标
159 a = a+6; //如果a不重置为0,那么a会不停的往上加，直到超出数组下标溢出，导致程序崩溃
160 }
161 ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,R.id.LS);//新建并配置ArrayAapeter
162 MyBaseAdapter mAdapter = new MyBaseAdapter();
163 LS.setAdapter(mAdapter);
164 }catch (JSONException e){
165 e.printStackTrace();
166 }
167 }
168
169 class MyBaseAdapter extends BaseAdapter{ //这里不解释
170
171 @Override
172 public int getCount() {
173 return Json.length;
174 }
175 @Override
176 public Object getItem(int position) {
177 return null;
178 }
179 @Override
180 public long getItemId(int position) {
181 return 0;
182 }
183 @Override
184 public View getView(int position, View convertView, ViewGroup parent) {
185 ViewHolder holder;
186 if(convertView == null){
187 convertView = LayoutInflater.from(getApplicationContext()).inflate(R.layout.homework_five_2,parent,false);
188 holder = new ViewHolder();
189 holder.mTextView = (TextView) convertView.findViewById(R.id.tv);
190 convertView.setTag(holder);
191 }else {
192 holder = (ViewHolder) convertView.getTag();
193 }
194 holder.mTextView.setText(Json[position]);
195 return convertView;
196 }
197 class ViewHolder {
198 TextView mTextView;
199 }
200 }
201
202 }
我们的布局文件用的listview,所以我们需要再写一个布局文件提供格式
1
2
3 xmlns:app="http://schemas.android.com/apk/res-auto"
4 android:layout_width="match_parent"
5 android:layout_height="match_parent">
6
7
8 android:id="@+id/tv"
9 android:layout_width="match_parent"
10 android:layout_height="match_parent"/>
11
12
结果如图
最后，赶时间写出来的，写的很烂，等过几天精简一下代码，等待更新哦!
来源：https://www.cnblogs.com/rebirther/p/12888087.html