httppost

import java.io.BufferedReader;
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;


public class TestHttpPost {

public static void main(String[] args) throws IOException {
//創建URL對象
URL url = new URL("http://127.0.0.1:8080/student/login.php");
//通過URL對象獲取一個HttpURLConnection對象
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");//設置請求方式爲POST
conn.setDoOutput(true);//設置允許輸出數據到服務器
//設置請求頭信息
conn.setRequestProperty("content-type", "application/x-www-form-urlencoded");
//獲取輸出流 通過輸出流將POST請求提交的數據發送到服務器端
String data = "username=admin&password=admin";
//獲取輸出流對象 通過輸出流將數據輸出到服務器端
OutputStream out = conn.getOutputStream();
out.write(data.getBytes());//數據寫出 輸出數據的操作 必須放置在讀取數據前
//獲取輸入流 通過該流可以獲取服務器端響應信息
InputStream in = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
//判斷響應狀態碼 
if(conn.getResponseCode() == 200){
System.out.println("服務器請求處理成功,返回的響應：");
String msg = null;
while((msg=reader.readLine())!=null){
System.out.println(msg);
}
}
//斷開連接
conn.disconnect();

}

}

##################################################

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

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

public class MainActivity extends Activity {
    private EditText et_username;
    private EditText et_password;

    private Button bt_show;

    String result="";

    /**post請求URL地址*/
    private static final String URL="";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();

        bt_show.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                //android4.0後的新的特性，網絡數據請求時不能放在主線程中。
                //9、使用線程執行訪問服務器，獲取返回信息後通知主線程更新UI或者提示信息。
                final Handler handler = new Handler() {
                    @Override
                    public void handleMessage(Message msg) {
                        if (msg.what == 1) {
                            //8、提示讀取結果
                            Toast.makeText(MainActivity.this, result, Toast.LENGTH_LONG).show();
                        }
                    }
                };
                // 啓動線程來執行任務
                new Thread() {
                    public void run() {
                        //請求網絡
                        loginByPost(et_username.getText().toString(), et_password.getText().toString());
                        Message m = new Message();
                        m.what = 1;
                        // 發送消息到Handler
                        handler.sendMessage(m);
                    }
                }.start();

            }
        });

    }

    private void init(){
        et_username=(EditText)findViewById(R.id.et_username);
        et_password=(EditText)findViewById(R.id.et_password);
        bt_show=(Button)findViewById(R.id.bt_login);
    }

    /**
     * 請求後臺，判斷登錄結果。
     * @param username
     * @param password
     */
    public void loginByPost(String username, String password) {
        try {
            //1、根據地址創建URL對象(網絡訪問的url)
            URL url = new URL(URL);
            //2、url.openConnection()打開網絡鏈接
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
            //3、設置請求的方式
            conn.setRequestMethod("POST");
            conn.setDoInput(true);//發送POST請求必須設置允許輸出
            conn.setDoOutput(true);//發送POST請求必須設置允許輸入
            //4、設置請求的頭
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("Charset", "utf-8");
            String data = "username=" + URLEncoder.encode(username, "UTF-8")
                    + "&password=" + URLEncoder.encode(password, "UTF-8");//傳遞的數據
            conn.setRequestProperty("Content-Length",String.valueOf(data.getBytes().length));
            //5、獲取輸出流
            OutputStream os = conn.getOutputStream();
            os.write(data.getBytes());
            os.flush();


            //6、獲取響應的輸入流對象
            InputStreamReader is = new InputStreamReader(conn.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(is);
            StringBuffer strBuffer = new StringBuffer();
            String line = null;
            //7、讀取服務器返回信息
            while ((line = bufferedReader.readLine()) != null) {
                strBuffer.append(line);
            }
            result = strBuffer.toString();

            //8、關閉InputStream、關閉http連接
            is.close();
            conn.disconnect();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}