详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

2022-12-02 20:33:43

前言，Android的网络通信的方式有两种：使用Socket或者HTTP，今天这一篇我们详细讲解使用HTTP实现的网络通信，HTTP又包括两种方式编程方式：

（1）HttpUrlConnection；

（2）HttpClient；

好了，我们直接进行讲解，当然之前也会有一部分有关Android网络通信的其他知识，我们也应该了解。

一.获取网络状态的方法

（1）MainActivity.java中的关键代码

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//网络管理类，可以判断是否能上网，以及网络类型
            ConnectivityManager cm=(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo info=cm.getActiveNetworkInfo();
            if(info!=null){
                Toast.makeText(MainActivity.this, "连网正常"+info.getTypeName(), Toast.LENGTH_SHORT).show();
            }else{
                Toast.makeText(MainActivity.this, "未连网", Toast.LENGTH_SHORT).show();
            }

（2）注意：一定要在主配置文件中增加这个权限

它是application的兄弟标签：

1 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

（3）OK，我们看一下我们的设备的上网状态和类型吧：

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

二.使用URL访问网页源码

（1）MainActivity.java：

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package com.example.l0903_urldata;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
/**
 * 访问网页源码
 * @author asus
 *
 */
public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        try {
            //访问百度的html文件的源码
            InputStream is=new URL("http://www.baidu.com").openStream();
            //读取数据的包装流
            BufferedReader br=new BufferedReader(new InputStreamReader(is));
            //str用于读取一行数据
            String str=null;
            //StringBuffer用于存储所欲数据
            StringBuffer sb=new StringBuffer();
            while((str=br.readLine())!=null){
                sb.append(str);
            }
            System.out.println(sb.toString());
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

（2）注意：有关网络的操作都需要在主配置文件里添加下面这个权限：

1 <uses-permission android:name="android.permission.INTERNET"/>

三.WebView 控件的简单使用

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package com.example.l0903_webview;
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
/**
 * 就是一个浏览器控件
 * 其实没什么用
 * @author asus
 *
 */
public class MainActivity extends Activity {
    private WebView wv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        wv=(WebView) findViewById(R.id.webView1);
        //WebView控件的方法，loadUrl用于加载指定的网络地址
        wv.loadUrl("http://www.baidu.com");
    }
}

运行效果：

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

四.使用HttpUrlConnection的编写方式实现Android的网络通信

1.首先，自己先搭建一个服务器：

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

2.下面是客户端的事了：

(1)通过get方式：

MainActivity.java：

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package com.example.l0903_httpurlcnectionget;
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 android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.TextView;
/**
 * 通过Get方法获取服务器的数据
 * 直接在地址中用"?+键值+value"的方式来使用
 * 所以传递的参数直接显示出来，不安全
 * @author asus
 *
 */
public class MainActivity extends Activity {
    private HttpURLConnection conn;
    private URL url;
    private InputStream is;
    private TextView tv;
    private EditText et;
    private String name;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv=(TextView) findViewById(R.id.textView1);
        et=(EditText) findViewById(R.id.editText1);
        findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
                                                                                                                                              
            @Override
            public void onClick(View v) {
                name=et.getText().toString();
                //定义访问的服务器地址，10.0.2.2是Android的访问的本地服务器地址
                String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp?name="+name;
                try {
                    //封装访问服务器的地址
                    url=new URL(urlDate);
                    try {
                        //打开对服务器的连接
                        conn=(HttpURLConnection) url.openConnection();
                        //连接服务器
                        conn.connect();
                        /**读入服务器数据的过程**/
                        //得到输入流
                        is=conn.getInputStream();
                        //创建包装流
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        //定义String类型用于储存单行数据
                        String line=null;
                        //创建StringBuffer对象用于存储所有数据
                        StringBuffer sb=new StringBuffer();
                        while((line=br.readLine())!=null){
                            sb.append(line);
                        }
                        //用TextView显示接收的服务器数据
                        tv.setText(sb.toString());
                        System.out.println(sb.toString());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

权限（同上面第二个，所有与网络有关的操作都需要添加，下面的就不再赘述了）

运行效果：

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

（2）通过post方式（安全）

MainActivity.java

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package com.example.l0903_httpurlconectionpost;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.TextView;
/**
 * 通过Post方法传递参数
 * 安全
 * @author asus
 *
 */
public class MainActivity extends Activity {
    private HttpURLConnection conn;
    private URL url;
    private InputStream is;
    private OutputStream os;
    private EditText et;
    private TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et=(EditText) findViewById(R.id.editText1);
        tv=(TextView) findViewById(R.id.tv);
        findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
                                                                                   
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp";
                try {
                    url=new URL(urlDate);
                    try {
                        //打开服务器
                        conn=(HttpURLConnection) url.openConnection();
                        //设置输入输出流
                        conn.setDoOutput(true);
                        conn.setDoInput(true);
                        //设置请求的方法为Post
                        conn.setRequestMethod("POST");
                        //Post方式不能缓存数据，则需要手动设置使用缓存的值为false
                        conn.setUseCaches(false);
                        //连接数据库
                        conn.connect();
                        /**写入参数**/
                        os=conn.getOutputStream();
                        //封装写给服务器的数据（这里是要传递的参数）
                        DataOutputStream dos=new DataOutputStream(os);
                        //写方法：name是key值不能变，编码方式使用UTF-8可以用中文
                        dos.writeBytes("name="+URLEncoder.encode(et.getText().toString(), "UTF-8"));
                        //关闭外包装流
                        dos.close();
                        /**读服务器数据**/
                        is=conn.getInputStream();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=null;
                        StringBuffer sb=new StringBuffer();
                        while((line=br.readLine())!=null){
                            sb.append(line);
                        }
                        tv.setText(sb.toString());
                        System.out.println(sb.toString());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                }
            }
        });
                                                                           
    }
}

五.使用HttpClient的编写方式实现Android的网络通信

1.服务器同上；

2.使用get的方式：

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package com.example.l0903_http_get;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
    private HttpGet get;
    private HttpClient cliet;
    private HttpResponse response;
    private HttpEntity entity;
    private InputStream is;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        get=new HttpGet("http://10.0.2.2:8080/My_Service/webdate.jsp?name=ooooooo");
        cliet=new DefaultHttpClient();
        try {
            response=cliet.execute(get);
            entity=response.getEntity();
            is=entity.getContent();
            BufferedReader br=new BufferedReader(new InputStreamReader(is));
            String line=null;
            StringBuffer sb=new StringBuffer();
            while((line=br.readLine())!=null){
                sb.append(line);
            }
            System.out.println(sb.toString());
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
                                                
    }
}

3.使用post的方式：

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package com.example.l0903_http_post;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
    //创建请求对象
    private HttpPost post;
    //创建客户端对象
    private HttpClient cliet;
    //创建发送请求的对象
    private HttpResponse response;
    //
    private UrlEncodedFormEntity urlEntity;
    //创建接收返回数据的对象
    private HttpEntity entity;
    //创建流对象
    private InputStream is;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //包装请求的地址
        post=new HttpPost("http://10.0.2.2:8080/My_Service/webdate.jsp");
        //创建默认的客户端对象
        cliet=new DefaultHttpClient();
        //用list封装要向服务器端发送的参数
        List<BasicNameValuePair> pairs=new ArrayList<BasicNameValuePair>();
        pairs.add(new BasicNameValuePair("name", "llllllllll"));
        try {
            //用UrlEncodedFormEntity来封装List对象
            urlEntity=new UrlEncodedFormEntity(pairs);
            //设置使用的Entity
            post.setEntity(urlEntity);
            try {
                //客户端开始向指定的网址发送请求
                response=cliet.execute(post);
                //获得请求的Entity
                entity=response.getEntity();
                is=entity.getContent();
                //下面是读取数据的过程
                BufferedReader br=new BufferedReader(new InputStreamReader(is));
                String line=null;
                StringBuffer sb=new StringBuffer();
                while((line=br.readLine())!=null){
                    sb.append(line);
                }
                System.out.println(sb.toString());
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
                                             
                                             
    }
}

4.实现HttpClient通信与AsyncTask异步机制的结合：

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package com.example.l0903_http_asynctask_get;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;
/**
 *
 * @author asus
 *
 */
public class MainActivity extends Activity {
    private TextView tv;// 创建请求对象
    private HttpGet httpGet;
    // 创建客户端对象
    private HttpClient httpClient;
    // 发送请求的对象
    private HttpResponse httpResponse;
    // 接收返回数据
    private HttpEntity httpEntity;
    // 创建流
    private InputStream in;
    private ProgressDialog pd;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        AsyncTask<String, Void, String> asyncTask = new AsyncTask<String, Void, String>() {
            @Override
            protected String doInString...  params) {
                String urlstr = params[0];
                httpGet = new HttpGet(urlstr);
                httpClient = new DefaultHttpClient();
                try {
                    // 向服务器端发送请求
                    httpResponse = httpClient.execute(httpGet);
                    httpEntity = httpResponse.getEntity();
                    in = httpEntity.getContent();
                    BufferedReader br = new BufferedReader(
                            new InputStreamReader(in));
                    String line = null;
                    StringBuffer sb = new StringBuffer();
                    while ((line = br.readLine()) != null) {
                        sb.append(line);
                    }
                    System.out.println(sb.toString());
                    return sb.toString();
                } catch (ClientProtocolException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return null;
            }
            @Override
            protected void onPostExecute(String result) {
                if (result != null) {
                    tv.setText(result);
                    pd.dismiss();// 消除dialog
                }
                super.onPostExecute(result);
            }
        };
        pd = ProgressDialog.show(this, "请稍后。。。", "正在请求数据");
        asyncTask.execute("http://10.0.2.2:8080/My_Service/webdate.jsp?name=haha&age=hh");
    }
}

运行效果：

详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

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