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
1 2 3 4 5 6 7 8 | //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:
二.使用URL访问网页源码
(1)MainActivity.java:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | 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:
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:
2.下面是客户端的事了:
(1)通过get方式:
MainActivity.java:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 | 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:
(2)通过post方式(安全)
MainActivity.java
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 | 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 | 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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 | 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:
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