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 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical"> 6 7 <Button 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 <Button 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 <ListView 19 android:layout_width="match_parent" 20 android:layout_height="wrap_content" 21 android:id="@+id/LS"/> 22 </LinearLayout>
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<String> adapter = new ArrayAdapter<String>(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<jsonArray.length();i++){ //会循环三次 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<String> adapter = new ArrayAdapter<String>(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 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent"> 6 7 <TextView 8 android:id="@+id/tv" 9 android:layout_width="match_parent" 10 android:layout_height="match_parent"/> 11 12 </LinearLayout>
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!
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