<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <EditText

        android:id="@+id/et_name"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:hint="请输入用户名"

        android:inputType="text" />

    <EditText

        android:id="@+id/et_pwd"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:hint="请输入密码"

        android:inputType="textPassword" />

    <Button

        android:onClick="LoginByGet"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="GET方式登录"

        />

     <Button

        android:onClick="LoginByPost"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="POST方式登录"

        />

</LinearLayout>

package com.wuyudong.loginclient;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import android.os.Build;

import android.os.Bundle;

import android.os.StrictMode;

import android.annotation.SuppressLint;

import android.annotation.TargetApi;

import android.app.Activity;

import android.text.TextUtils;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends Activity {

    private EditText et_name;

    private EditText et_pwd;

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        et_name = (EditText) findViewById(R.id.et_name);

        et_pwd = (EditText) findViewById(R.id.et_pwd);

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()

                .permitAll().build();

        StrictMode.setThreadPolicy(policy);

    }

    public void LoginByGet(View view) {

        String name = et_name.getText().toString().trim();

        String pwd = et_pwd.getText().toString().trim();

        if (TextUtils.isEmpty(name) || TextUtils.isEmpty(pwd)) {

            Toast.makeText(this, "用户名密码不能为空", 0).show();

        } else {

            // 模拟http请求，提交数据到服务器

            String path = "http://169.254.168.71:8080/web/LoginServlet?username="

                    + name + "&password=" + pwd;

            try {

                URL url = new URL(path);

                // 2.建立一个http连接

                HttpURLConnection conn = (HttpURLConnection) url

                        .openConnection();

                // 3.设置一些请求方式

                conn.setRequestMethod("GET");// 注意GET单词字幕一定要大写

                conn.setRequestProperty(

                        "User-Agent",

                        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36");

                int code = conn.getResponseCode(); // 服务器的响应码 200 OK //404 页面找不到

                                                    // // 503服务器内部错误

                if (code == 200) {

                    InputStream is = conn.getInputStream();

                    // 把is的内容转换为字符串

                    ByteArrayOutputStream bos = new ByteArrayOutputStream();

                    byte[] buffer = new byte[1024];

                    int len = -1;

                    while ((len = is.read(buffer)) != -1) {

                        bos.write(buffer, 0, len);

                    }

                    String result = new String(bos.toByteArray());

                    is.close();

                    Toast.makeText(this, result, 0).show();

                } else {

                    Toast.makeText(this, "请求失败，失败原因: " + code, 0).show();

                }

            } catch (Exception e) {

                e.printStackTrace();

                Toast.makeText(this, "请求失败，请检查logcat日志控制台", 0).show();

            }

        }

    }

    /**

     * 采用post的方式提交数据到服务器

     *

     * @param view

     */

    public void LoginByPost(View view) {

        String name = et_name.getText().toString().trim();

        String pwd = et_pwd.getText().toString().trim();

        if (TextUtils.isEmpty(name) || TextUtils.isEmpty(pwd)) {

            Toast.makeText(this, "用户名密码不能为空", 0).show();

        } else {

            try {

                String path = "http://169.254.168.71:8080/web/LoginServlet?username="

                        + name + "&password=" + pwd;

                // 1.定义请求url

                URL url = new URL(path);

                // 2.建立一个http的连接

                HttpURLConnection conn = (HttpURLConnection) url

                        .openConnection();

                // 3.设置一些请求的参数

                conn.setRequestMethod("POST");

                conn.setRequestProperty(

                        "User-Agent",

                        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36");

                conn.setRequestProperty("Content-Type",

                        "application/x-www-form-urlencoded");

                String data = "username=" + name + "&password=" + pwd;

                conn.setRequestProperty("Content-Length", data.length() + "");

                conn.setConnectTimeout(5000);//设置连接超时时间

                conn.setReadTimeout(5000); //设置读取的超时时间

                // 4.一定要记得设置 把数据以流的方式写给服务器

                conn.setDoOutput(true); // 设置要向服务器写数据

                conn.getOutputStream().write(data.getBytes());

                int code = conn.getResponseCode(); // 服务器的响应码 200 OK //404 页面找不到

                // // 503服务器内部错误

                if (code == 200) {

                    InputStream is = conn.getInputStream();

                    // 把is的内容转换为字符串

                    ByteArrayOutputStream bos = new ByteArrayOutputStream();

                    byte[] buffer = new byte[1024];

                    int len = -1;

                    while ((len = is.read(buffer)) != -1) {

                        bos.write(buffer, 0, len);

                    }

                    String result = new String(bos.toByteArray());

                    is.close();

                    Toast.makeText(this, result, 0).show();

                } else {

                    Toast.makeText(this, "请求失败，失败原因: " + code, 0).show();

                }

            } catch (Exception e) {

                e.printStackTrace();

                Toast.makeText(this, "请求失败，请检查logcat日志控制台", 0).show();

            }

        }

    }

}