HTTP网络请求GSON解析网络不可用跳转到设置
//1主 mainactivity界面
package com.example.guoxinyu20181101;
import android.annotation.SuppressLint;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.UrlQuerySanitizer;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import com.google.gson.Gson;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Collections;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private ListView listView;
private Button button;
private ConnectionBase mBase;
private final int UPDATE_UI = 1;
@SuppressLint("HandlerLeak")
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case UPDATE_UI:
// List<ConnectionBean.Result> lists = (List<ConnectionBean.Result>) msg.obj;
List<List<String>> lists = (List<List<String>>) msg.obj;
mBase.setmlists(lists);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//获取资源id
listView = findViewById(R.id.lv_list);
button = findViewById(R.id.btn);
mBase = new ConnectionBase(MainActivity.this);
listView.setAdapter(mBase);
//点击加载数据
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//判断网络是否可用
if (!NetUtil.hasNetWork(MainActivity.this)) {
showNotNetWork();
return;
}
new Thread(new Runnable() {
@Override
public void run() {
requestConnection();
}
}).start();
}
});
//点击监听
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
List<String> data = mBase.getItem(position);
Toast.makeText(MainActivity.this, data.get(0) + ":" + data.get(1), Toast.LENGTH_SHORT).show();
}
});
}
//弹框提示网络的方法
private void showNotNetWork() {
new AlertDialog.Builder(MainActivity.this)
.setTitle("无网络")
.setMessage("当前网络不可用，是否去设置？")
.setPositiveButton("确认", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
Intent intent = new Intent("android.settings.WIRELESS_SETTINGS");
startActivity(intent);
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.show();
}
//加载数据的方法
private String urlStr = "https://suggest.taobao.com/sug?code=utf-8&q=%E6%89%8B%E6%9C%BA";
public void requestConnection() {
try {
//定义url地址
URL url = new URL(urlStr);
//打开连接
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//设置请求方式
urlConnection.setRequestMethod("GET");
//设置超时
urlConnection.setReadTimeout(5000);
urlConnection.setConnectTimeout(5000);
//获取请求码
int responseCode = urlConnection.getResponseCode();
if (responseCode == 200) {
String json = stream2String(urlConnection.getInputStream());
//得到gson
Gson gson = new Gson();
ConnectionBean connectionBean = gson.fromJson(json, ConnectionBean.class);
handler.sendMessage(handler.obtainMessage(UPDATE_UI, connectionBean.getResult()));
}
} catch (Exception e) {
e.printStackTrace();
}
}
//字节流转换为字符流
public String stream2String(InputStream is) throws IOException {
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
StringBuilder builder = new StringBuilder();
for (String tem = br.readLine(); tem != null; tem = br.readLine()) {
builder.append(tem);
}
return builder.toString();
}
}
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//适配器界面
package com.example.guoxinyu20181101;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
public class ConnectionBase extends BaseAdapter {
private List<List<String>> lists;
private Context mContext;
public ConnectionBase(Context mContext) {
this.mContext = mContext;
//初始化
lists = new ArrayList<>();
}
public void setmlists(List<List<String>> lists) {
this.lists = lists;
notifyDataSetChanged();
}
@Override
public int getCount() {
return lists.size();
}
@Override
public List<String> getItem(int position) {
return lists.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.listitem, parent, false);
holder = new ViewHolder();
holder.text = convertView.findViewById(R.id.text);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.text.setText(getItem(position).get(0));
return convertView;
}
class ViewHolder {
private TextView text;
}
}
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//判断是否有网络的类
package com.example.guoxinyu20181101;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
public class NetUtil {
//判断是否有网络
public static boolean hasNetWork(Context context){
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
return activeNetworkInfo!=null && activeNetworkInfo.isAvailable();
}
}
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//存放数据的BEAN类
package com.example.guoxinyu20181101;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
public class NetUtil {
//判断是否有网络
public static boolean hasNetWork(Context context){
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
return activeNetworkInfo!=null && activeNetworkInfo.isAvailable();
}
}
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//配置文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.guoxinyu20181101">
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
<!--跳转到网络设置的权限-->
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
</activity>
</application>
</manifest>
