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Android 用HttpUrlConnection

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悬赏园豆:10 [已关闭问题] 关闭于 2020-06-22 10:16

问题:通过HttpUrlConnection获取网站数据 ,
描述:参照书本的例程.xml和.java如下,并已在AndroidManifest.xml文件中添加了
<uses-permission android:name="android.permission.INTERNET"/> 但模拟运行程序时,点击button并无数据返回显示,想请教下应该如何解决?

.java文件

package com.example.onenet_block_get;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

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;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    TextView responseText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.testget);
        Button sendRequest = (Button) findViewById(R.id.send_request);
        responseText = (TextView) findViewById(R.id.reponse_text);
        sendRequest.setOnClickListener(this);
    }

    public void onClick(View v) {
        if (v.getId() == R.id.send_request) {
            sendRequestWithHttpURLConnection();
        }
    }

    private void sendRequestWithHttpURLConnection() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                BufferedReader reader = null;
                try {
                    URL url = new URL("http://www.baidu.com");
                    connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    InputStream in = connection.getInputStream();

                    reader =  new BufferedReader(new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while ((line = reader.readLine()) !=null ) {
                        response.append(line);
                    }
                    showResponse(response.toString());
                }catch (Exception e){
                    e.printStackTrace();
                }finally {
                    if(reader != null) {
                        try {
                            reader.close();
                        }catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if(connection != null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }

    private void showResponse(final String response) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                responseText.setText(response);
            }
        });
    }
}

.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/send_request"
        android:text="Send Request"/>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/reponse_text"/>
    </ScrollView>
</LinearLayout>
stuMartin的主页 stuMartin | 初学一级 | 园豆:198
提问于:2020-06-20 22:09
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所有回答(1)
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将原有代码

URL url = new URL("http://www.baidu.com");

修改成

URL url = new URL("https://www.baidu.com");
stuMartin | 园豆:198 (初学一级) | 2020-06-22 10:15
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