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Android网络编程之传递数据给服务器(一)

栏目:综合技术时间:2014-10-08 08:00:00

Android网络编程之传递数据给服务器(一)

 

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因为Android程序需要和服务器进行通信,所以需要服务器端提供的支持。

一、通过GET方式传递数据给服务器

通过GET方式上传数据主要适用于数据大小不超过2KB,且对安全性要求不高的情况下。

1.创建服务器端:

服务器端项目结构:

通过GET方式传递数据给服务器――服务器端项目结构

第一步:创建控制器Servlet 

package com.jph.sgm.servlet; 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; /** * Servlet implementation class ServletForGETMethod */ @WebServlet("/ServletForGETMethod") public class ServletForGETMethod extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public ServletForGETMethod() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //获取请求的参数(使用utf-8进行解码,然后用进行ISO8859-1编码) // String name=new String(request.getParameter("name").getBytes("ISO8859-1"),"utf-8"); String name=request.getParameter("name"); String pwd=request.getParameter("pwd"); System.out.println("name:"+name+" pwd:"+pwd); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } }

第二步:测试Servlet

发布项目并在浏览器中输入:http://localhost:8080/ServerForGETMethod/ServletForGETMethod?name=aa&pwd=124

可以再控制台看到如下图的输出:


通过GET方式传递数据给服务器――服务器端测试结果

至此服务器端项目已经完成。下面开始创建Android端项目。

2.创建Android端:

Android端项目结构:

通过GET方式传递数据给服务器――Android端项目结构


第一步:创建Android端项目的业务逻辑层

核心代码:SendDateToServer.java:

package com.jph.sdg.service; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; import java.util.HashMap; import java.util.Map; import android.os.Handler; /** * 通过GET方式向服务器发送数据 * @author jph * Date:2014.09.27 */ public class SendDateToServer { private static String url="http://10.219.61.117:8080/ServerForGETMethod/ServletForGETMethod"; public static final int SEND_SUCCESS=0x123; public static final int SEND_FAIL=0x124; private Handler handler; public SendDateToServer(Handler handler) { // TODO Auto-generated constructor stub this.handler=handler; } /** * 通过Get方式向服务器发送数据 * @param name 用户名 * @param pwd 密码 */ public void SendDataToServer(String name,String pwd) { // TODO Auto-generated method stub final Map<String, String>map=new HashMap<String, String>(); map.put("name", name); map.put("pwd", pwd); new Thread(new Runnable() { @Override public void run() { // TODO Auto-generated method stub try { if (sendGetRequest(map,url,"utf-8")) { handler.sendEmptyMessage(SEND_SUCCESS);//通知主线程数据发送成功 }else { //将数据发送给服务器失败 } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }).start(); } /** * 发送GET请求 * @param map 请求参数 * @param url 请求路径 * @return * @throws Exception */ private boolean sendGetRequest(Map<String, String> param, String url,String encoding) throws Exception { // TODO Auto-generated method stub //http://localhost:8080/ServerForGETMethod/ServletForGETMethod?name=aa&pwd=124 StringBuffer sb=new StringBuffer(url); if (!url.equals("")&!param.isEmpty()) { sb.append("?"); for (Map.Entry<String, String>entry:param.entrySet()) { sb.append(entry.getKey()+"="); sb.append(URLEncoder.encode(entry.getValue(), encoding)); sb.append("&"); } sb.deleteCharAt(sb.length()-1);//删除字符串最后 一个字符“&” } HttpURLConnection conn=(HttpURLConnection) new URL(sb.toString()).openConnection(); conn.setConnectTimeout(5000); conn.setRequestMethod("GET");//设置请求方式为GET if (conn.getResponseCode()==200) { return true; } return false; } }

第三步:创建Activity

 

package com.jph.sdg.activity; import com.jph.sdg.R; import com.jph.sdg.service.SendDateToServer; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.app.Activity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; /** * 通过GET方式向服务器发送数据,通过GET方式上传数据主要适用于数 * 据大小不超过2KB,且对安全性要求不高的情况下。 * @author jph * Date:2014.09.27 */ public class MainActivity extends Activity { private EditText edtName,edtPwd; private Button btnSend; Handler handler=new Handler(){ public void handleMessage(Message msg) { switch (msg.what) { case SendDateToServer.SEND_SUCCESS: Toast.makeText(MainActivity.this, "登陆成功", Toast.LENGTH_SHORT).show(); break; case SendDateToServer.SEND_FAIL: Toast.makeText(MainActivity.this, "登陆失败", Toast.LENGTH_SHORT).show(); break; default: break; } }; }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); edtName=(EditText)findViewById(R.id.edtName); edtPwd=(EditText)findViewById(R.id.edtPwd); btnSend=(Button)findViewById(R.id.btnSend); btnSend.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String name=edtName.getText().toString(); String pwd=edtPwd.getText().toString(); if (edtName.equals("")||edtPwd.equals("")) { Toast.makeText(MainActivity.this, "用户名或密码不能为空", Toast.LENGTH_LONG).show(); }else { new SendDateToServer(handler).SendDataToServer(name, pwd); } } }); } }

至此Android端项目已经完成了。下面就让我们看一下APP运行效果吧:

Android运行效果图:


通过GET方式传递数据给服务器――Android端运行效果图2


二、关于通过GET方式传递数据给服务器时,中文乱码的解决方案

当客户端向服务器发送中文时服务器端会出现乱码现象,如下图:


关于通过GET方式传递数据给服务器时,中文乱码的解决方案


    出现乱码的原因主要是,Android客户端我们采用的是UTF-8编码,而Tomcat默认采用的是ISO8858-1编码,所以会出现中文乱码的现象。

解决方案有两种:

第一种解决方案:

是使用UTF-8解码请求参数得到汉字,然后再通过ISO8859-1进行编码。此时服务器端的Servlet是:

package com.jph.sgm.servlet; 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; /** * Servlet implementation class ServletForGETMethod */ @WebServlet("/ServletForGETMethod") public class ServletForGETMethod extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public ServletForGETMethod() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //获取请求的参数(使用utf-8进行解码,然后用进行ISO8859-1编码) String name=new String(request.getParameter("name").getBytes("ISO8859-1"),"utf-8"); // String name=request.getParameter("name"); String pwd=request.getParameter("pwd"); System.out.println("name:"+name+" pwd:"+pwd); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } }

  

运行结果如下图:


UTF-8解码请求参数得到汉字,然后再通过ISO8859-1进行编码


第二种解决方案:

         下面我们采用过滤器的方式来解决乱码的问题:

第一步:建立一个Filter过滤器。

EncodingFilter.java

package com.jph.sgm.filter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; /** * Servlet Filter implementation class EncodingFilter */ @WebFilter("/*") public class EncodingFilter implements Filter { /** * Default constructor. */ public EncodingFilter() { // TODO Auto-generated constructor stub } /** * @see Filter#destroy() */ public void destroy() { // TODO Auto-generated method stub } /** * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain) */ public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub HttpServletRequest req=(HttpServletRequest) request; if ("GET".equals(req.getMethod())) { HttpServletRequestEncodingWrapper wrapper=new HttpServletRequestEncodingWrapper(req); chain.doFilter(wrapper, response); }else { req.setCharacterEncoding("utf-8"); chain.doFilter(request, response); } } /** * @see Filter#init(FilterConfig) */ public void init(FilterConfig fConfig) throws ServletException { // TODO Auto-generated method stub } }

 

上面的过滤器因为设置了过滤路径为*/所以会过滤所有的Servlet

在上面的过滤器中用到了一个包装器,HttpServletRequestEncodingWrapper.java

package com.jph.sgm.filter; import java.io.UnsupportedEncodingException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; public class HttpServletRequestEncodingWrapper extends HttpServletRequestWrapper { private HttpServletRequest request; public HttpServletRequestEncodingWrapper(HttpServletRequest request) { // TODO Auto-generated constructor stub super(request); this.request=request; } @Override public String getParameter(String name) { // TODO Auto-generated method stub String value=request.getParameter(name); if (value!=null) { try {//用utf-8进行解码,然后用ISO8859-1进行编码 return new String(value.getBytes("ISO8859-1"),"utf-8"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return super.getParameter(name); } }


重新运行项目可以看到服务器会将客户端发来的数据用UTF-8进行解码,用ISO8859-1进行编码。运行效果图如下:

采用过滤器的方式来解决乱码的问题


 Android网络编程之传递数据给服务器(二)――通过POST的方式将数据传递给服务器

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