android http同步请求

1、界面

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:orientation="vertical"
     android:layout_height="match_parent"
     tools:context=".MainActivity" >

     <EditText
         android:id="@+id/et_username"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:hint="请输入用户名"
         android:text="张三"
          />

     <EditText
         android:id="@+id/et_password"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:hint="请输入密码"
         android:inputType="textPassword" />

     <Button
         android:onClick="myGetData"
         android:id="@+id/button1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="登陆" />

 </LinearLayout>

2、MainActivity代码，用来响应button代码

 package com.example.getdata;

 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;

 import com.example.getdata.service.LoginService;

 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
 import android.app.Activity;
 import android.view.Menu;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.Toast;

 public class MainActivity extends Activity {

     private EditText et_username;
     private EditText et_password;
     /*private Handler handler = new Handler(){

         @Override
         public void handleMessage(android.os.Message msg) {
             // TODO Auto-generated method stub

         }

     };*/
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         et_username = (EditText)findViewById(R.id.et_username);
         et_password = (EditText)findViewById(R.id.et_password);
     }

     public void myGetData(View view){
         final String username = et_username.getText().toString().trim();
         final String password = et_password.getText().toString().trim();
         System.out.println("username:" + username);
         System.out.println("password:" + password);
         new Thread(){
             public void run(){
                 //final String result = LoginService.loginByGet(username, password);
                 //final String result = LoginService.loginByPost(username, password);
                 //final String result = LoginService.loginByClientGet(username, password);
                 final String result = LoginService.loginByClientPost(username, password);
                 if(result != null){
                     runOnUiThread(new Runnable(){
                         @Override
                         public void run() {
                             // TODO Auto-generated method stub
                             Toast.makeText(MainActivity.this, result, 0).show();
                         }

                     });
                 }else{
                     runOnUiThread(new Runnable(){
                         @Override
                         public void run() {
                             // TODO Auto-generated method stub
                             Toast.makeText(MainActivity.this, "请求不成功!", 0).show();
                         }

                     });
                 }
             };
         }.start();
     }

 }

3、http请求同步代码

 package com.example.getdata.service;

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.List;

 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
 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.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.impl.client.DefaultHttpClient;
 import org.apache.http.message.BasicNameValuePair;

 import com.example.getdata.utils.StreamTools;
 /*
  * 注意事项：在发送请求时，如果有中文，注意把它转换为相应的编码
  */
 public class LoginService {

     public static String loginByGet(String username, String password){
         try {
             String path = "http://192.168.1.100/android/index.php?username=" + URLEncoder.encode(username, "utf-8") + "&password=" + password;
             URL url = new URL(path);
             HttpURLConnection conn = (HttpURLConnection)url.openConnection();
             conn.setRequestMethod("GET");
             conn.setReadTimeout(5000);
             //conn.setRequestProperty(field, newValue);
             int code = conn.getResponseCode();
             if(code == 200){
                 InputStream is = conn.getInputStream();
                 String result = StreamTools.readInputStream(is);
                 return result;
             }else{
                 return null;
             }
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
             return null;
         }

     }

     public static String loginByPost(String username, String password){
         String path = "http://192.168.1.101/android/index.php";
         try {
             URL url = new URL(path);
             HttpURLConnection conn = (HttpURLConnection)url.openConnection();
             conn.setRequestMethod("POST");
             conn.setReadTimeout(5000);
             conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
             String data = "username=" + URLEncoder.encode(username, "utf-8") + "&password=" + password;
             conn.setRequestProperty("Content-Length", data.length() + "");
             //允许向外面写数据
             conn.setDoOutput(true);
             //获取输出流
             OutputStream os = conn.getOutputStream();
             os.write(data.getBytes());
             int code = conn.getResponseCode();
             if(code == 200){
                 InputStream is = conn.getInputStream();
                 String result = StreamTools.readInputStream(is);
                 return result;
             }else{
                 System.out.println("----111");
                 return null;
             }
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
             System.out.println("----2222");
             return null;
         }

     }

     public static String loginByClientGet(String username, String password){
         try{
             //1、打开一个浏览器
             HttpClient client = new DefaultHttpClient();

             //输入地址ַ
             String path = "http://192.168.1.101/android/index.php?username=" + URLEncoder.encode(username, "utf-8") + "&password=" + password;
             HttpGet httpGet = new HttpGet(path);

             //敲回车
             HttpResponse response = client.execute(httpGet);

             //获取返回状态码
             int code = response.getStatusLine().getStatusCode();
             if(code == 200){
                 InputStream is = response.getEntity().getContent();
                 String result = StreamTools.readInputStream(is);
                 return result;
             }else{
                 System.out.println("----111");
                 return null;
             }
         }catch(Exception e){
             e.printStackTrace();
             System.out.println("----222");
             return null;
         }

     }

     public static String loginByClientPost(String username, String password){
         try {
             //�������
             HttpClient client = new DefaultHttpClient();

             //�����ַ
             String path = "http://192.168.1.101/android/index.php";
             HttpPost httpPost = new HttpPost(path);
             //ָ��Ҫ�ύ�����ʵ��
             List<NameValuePair> parameters = new ArrayList<NameValuePair>();
             parameters.add(new BasicNameValuePair("username",username));
             parameters.add(new BasicNameValuePair("password",password));

             httpPost.setEntity(new UrlEncodedFormEntity(parameters,"utf-8"));
             HttpResponse response = client.execute(httpPost);
             //��ȡ�������
             int code = response.getStatusLine().getStatusCode();
             if(code == 200){
                 InputStream is = response.getEntity().getContent();
                 String result = StreamTools.readInputStream(is);
                 return result;
             }else{
                 System.out.println("----111");
                 return null;
             }
         } catch (Exception e) {
             // TODO Auto-generated catch block
             System.out.println("----222");
             e.printStackTrace();
             return null;
         }
     }
 }

4、把输入流转换为字符串

package com.example.getdata.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class StreamTools {
    /*
     * 功能：把inputStream转化为字符串
     */
    public static String readInputStream(InputStream is){
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            int len=0;
            byte[] buffer = new byte[1024];
            while((len = is.read(buffer)) != -1){
                baos.write(buffer, 0, len);
            }
            baos.close();
            is.close();
            byte[] result = baos.toByteArray();
            return new String(result);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }

    }
}

5、清单文件

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

最后：一般来说，子线程是无法改变UI的，但是这里采用runOnUiThread方式是可以的，而不是采用发送消息的方式