HttpURLConnection访问网络

来源：互联网发布：centos 配置smtp 编辑：程序博客网时间：2024/06/09 17:15

1、HttpURLConnection访问网络时实例化对象如下：
URL url = new URL("http://www.baidu.com");//获取地址 URLConnection connection = url.openConnection();
2、发送GET请求：默认发送的就是GET请求。
Android代码如下：
`

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;import java.net.URLEncoder;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Base64;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {    private EditText urlcontent;    private TextView textcontent;    private Button submit;    private String result;    private Handler handler;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        urlcontent = (EditText) this.findViewById(R.id.urlcontent);        textcontent = (TextView) this.findViewById(R.id.textcontent);        submit = (Button) this.findViewById(R.id.submit);        submit.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                if("".equals(urlcontent.getText().toString())){                    Toast.makeText(getApplicationContext(), "请输入网址", Toast.LENGTH_SHORT).show();                    return;                }                new Thread(new Runnable() {                    @Override                    public void run() {                        send();                        Message m = handler.obtainMessage();                        handler.sendMessage(m);                    }                }).start();            }        });        handler = new Handler(){            @Override            public void handleMessage(Message msg) {                if(result!=null){                    textcontent.setText(result);                    urlcontent.setText("");                }                super.handleMessage(msg);            }        };    }    //发送信息    public void send(){//      String urlEdit = urlcontent.getText().toString();        String target="";//      target = "http://192.168.1.100:8080/blog/index.jsp?aaaaacontent="//                  +base64(urlcontent.getText().toString().trim());    //要访问的URL地址        target = urlcontent.getText().toString();        try {            URL url = new URL(target);//获取地址            URLConnection connection = url.openConnection();            InputStreamReader in = new InputStreamReader(connection.getInputStream());//获取输入流            BufferedReader breader = new BufferedReader(in);            String inputLine = null;            while((inputLine = breader.readLine())!=null){                result+=inputLine+"\n";            }            in.close();        } catch (MalformedURLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    //对字符串进行Base64编码    public String base64(String content){        try {            content=Base64.encodeToString(content.getBytes("utf-8"), Base64.DEFAULT);   //对字符串进行Base64编码            content=URLEncoder.encode(content); //对字符串进行URL编码        } catch (UnsupportedEncodingException e) {            e.printStackTrace();    //输出异常信息        }        return content;    }}

activity_main代码如下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:gravity="center_horizontal"    >    <EditText        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="http://www.baidu.com"        android:id="@+id/urlcontent"        />    <Button         android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:id="@+id/submit"        android:text="提交"        />    <ScrollView         android:id="@+id/scrollview"        android:layout_weight="1"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        >        <TextView             android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:id="@+id/textcontent"            />    </ScrollView></LinearLayout>

`
3、发送POST请求：setRequestMethod(“POST”);需要判断是否响应成功，响应成功方可读取数据。
访问网站以http://www.baidu.com为例，所以可以读取到数据，写是无法写成功的。
以下代码有写的操作，步骤正确，只是无法写成功。可以自己搭建服务器代码。

通过以下方法设置相关内容`urlConn.setDoInput(true);//像连接中写入数据urlConn.setDoOutput(true);//从连接中读取数据urlConn.setUseCaches(false);//禁止缓存urlConn.setInstanceFollowRedirects(true);//自动执行HTTP重定向urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");//设置内容类型

Android代码如下：其他代码与GET一样，只更改了send()方法。
`
public void send(){
// String target = “http://192.168.1.100:8080/blog/index.jsp“;//要提交的目的地址
target = urlcontent.getText().toString();
URL url;
try {
url = new URL(target);
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();//创建一个Http连接
urlConn.setRequestMethod(“POST”);//使用POST请求方式
urlConn.setDoInput(true);//像连接中写入数据
urlConn.setDoOutput(true);//从连接中读取数据
urlConn.setUseCaches(false);//禁止缓存
urlConn.setInstanceFollowRedirects(true);//自动执行HTTP重定向
urlConn.setRequestProperty(“Content-Type”, “application/x-www-form-urlencoded”);//设置内容类型
DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());//获取输出流
String param = “name=”+URLEncoder.encode(“lili”, “utf-8”)+”&content=”+URLEncoder.encode(“jiayou”, “utf-8”);
out.writeBytes(param);//将要传递的数据写入数据输出流
out.flush();//输出缓存
out.close();

        // 判断是否响应成功        if(urlConn.getResponseCode() == HttpURLConnection.HTTP_OK){            InputStreamReader in = new InputStreamReader(urlConn.getInputStream());            BufferedReader buffer = new BufferedReader(in);            String inputLine = null;            while((inputLine = buffer.readLine()) != null){                result += inputLine+"\n";             }            in.close();        }        urlConn.disconnect();    } catch (MalformedURLException e) {        // TODO Auto-generated catch block        e.printStackTrace();    } catch (IOException e) {        // TODO Auto-generated catch block        e.printStackTrace();    }}

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