首先搭建模拟web 服务器，新建动态web项目，servlet代码如下：
package com.wuyudong.web; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.catalina.User; /** * Servlet implementation class LoginServlet */ @WebServlet("/LoginServlet") public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse * response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username"); String password = request.getParameter("password"); System.out.println("用户名：" + username); System.out.println("用户名：" + password); if ("wuyudong".equals(username) && "123".equals(password)) { response.getOutputStream().write("login success".getBytes()); } else { response.getOutputStream().write("login failed".getBytes()); } } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse * response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } }
再新建一个jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>登录页面</title> </head> <body> <form action="LoginServlet" method="get"> 用户名：<input name="username" type="text"><br> 密码：<input name="password" type="password"><br> <input type="submit"> </form> </body> </html>
新建android项目，页面布局：
<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="login" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="登录" /> </LinearLayout>
代码如下：
package com.wuyudong.loginclient; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; import android.os.Bundle; import android.app.Activity; import android.text.Editable; import android.text.TextUtils; import android.view.Menu; 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; @Override 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); } public void login(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(); } } } }
添加权限：android.permission.INTERNET
运行项目后点击按钮后提示错误：
06-18 21:08:16.237: W/System.err(7417): android.os.NetworkOnMainThreadException
android强行让4.0以后的版本不去检查主线程访问网络。
解决办法，可以在onCreate里面加上下面这段代码:
StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
搞定