用Tomcat和Eclipse开发Servlet程序

【1】、 安装eclipse
1)、 在官网上直接下载Eclipse IDE for Java EE Developers，解压即可；
【2】、 eclipse安装tomcat插件：
1)、 在http://www.eclipsetotale.com/tomcatPlugin.html上下载tomcatPluginV33.zip
2)、 解压到eclipse目录下的plugins目录中
3)、 重新启动eclipse
4)、 如果你在Window  ->  Prefences中找不到Server选择的话，说明你的eclipse版本下错了，要下载Eclipse IDE for Java EE Developers
5)、 在Server一栏中选择Runtime Environment，在右边选择Add，选择好安装路径后download。下载完成后点击finished，看到选择版本的tomcatServer已经建立
6)、 在Window  ->  Prefences  ->  Tomcat配置tomcat。Tomcat home 选择刚才下载的目录
7)、 点击start tomcat按钮，可以发现大量打印信息，在浏览器中输入http://localhost:8080，出现tomcat的网页，证明已经安装好了。
【3】、 新建Servlet测试程序
1)、 选择菜单File->New->Project... ，在新建项目向导中选择 Web->Dynamic Web Project,project name为MyFirstDynamicWebProject，一路next，最后选择生成web.xml；
2)、 new 一个class，package com.johnny.test，name为helloworld，super class 为HttpServlet；

3)、 code：

package com.johnny.test;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class HelloWorld extends HttpServlet implements javax.servlet.Servlet{
	   /* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#HttpServlet()
		 */
		public HelloWorld() {
			super();
		}   	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, 
		     HttpServletResponse response)
		 */
		protected void doGet(HttpServletRequest request, HttpServletResponse response) 
		    throws ServletException, IOException {
			response.getWriter().write("Hello, world 1112!");
		}  	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, 
		     HttpServletResponse response)
		 */
		protected void doPost(HttpServletRequest request, HttpServletResponse response) 
		    throws ServletException, IOException {
			// TODO Auto-generated method stub
		} 
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <servlet>
  	<servlet-name>HelloWorld</servlet-name>
  	<servlet-class>com.johnny.test.HelloWorld</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>HelloWorld</servlet-name>
  	<url-pattern>/helloworld</url-pattern>
  </servlet-mapping>
  
</web-app>

4)、 右键点击HelloWorld.java，选择rus as ：run on server，在浏览器上会显示：Hello, world 1112!

5)、 或者右键点击工程，export MyFirstDynamicWebProject.war，然后放到ubuntu的tomcat的webapps目录下面，在浏览器上输入网址：http://localhost:8080/MyFirstDynamicWebProject/helloworld，也会出现Hello, world 1112!

【4】、ubuntu安装tomcat：
1、从http://tomcat.apache.org/download-70.cgi 下载core apache-tomcat-7.0.41.tar.gz
2、确保jdk的路径已经配置好
3、解压运行 sudo ./startup.sh
4、测试：在浏览器中输入http://localhost:8080，出现tomcat网页，则安装成功；
【5】、

public class HelloWorld extends HttpServlet implements javax.servlet.Servlet{
	   /* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#HttpServlet()
		 */
		public HelloWorld() {
			super();
		}   	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, 
		     HttpServletResponse response)
		 */
		protected void doGet(HttpServletRequest request, HttpServletResponse response) 
		    throws ServletException, IOException {
			///*
			StringBuffer xmlInfo = new StringBuffer();    
			InputStream in = request.getInputStream();
			BufferedInputStream buf = new BufferedInputStream(in);
			byte buffer[] = new byte[1024];
			int iRead;
			while ((iRead = buf.read(buffer)) != -1)
				xmlInfo.append(new String(buffer, 0, iRead));
			buf.close();
			String result = "";

			String recievxml = xmlInfo.toString();// XMLUtile.filterStringXml(xmlInfo.toString());
				
			System.out.println(recievxml);
	
			String para = request.getParameter("user");
			System.out.println("usr = "+para);
			//*/
			System.out.println("hello world");
			
			response.getWriter().write("Hello, world !");
		}  	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, 
		     HttpServletResponse response)
		 */
		protected void doPost(HttpServletRequest request, HttpServletResponse response) 
		    throws ServletException, IOException {
			// TODO Auto-generated method stub
			System.out.println("hello world doPost");
			doGet(request,response);
			response.getWriter().write("Hello, world !");
		} 
		/*
		public String getMethod(String xmlInfo) throws DocumentException {
			String method = "";
			try {
				SAXReader reader = new SAXReader();
				Document doc = reader.read(new ByteArrayInputStream(xmlInfo
						.getBytes()));
				Element rootElement = doc.getRootElement();
				method = rootElement.attributeValue("method");
			} catch (Exception e) {
				e.printStackTrace();
			}
			return method;

		}
		*/
}

index.html

<html>
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
		<title>dongle settings</title>
		<script type="text/javascript" src="./Global/jquery.min.js"></script>
		<script type="text/javascript" src="./Global/jquery.json.min.js"></script>

		<script language="javascript">

			$(window).load(function(){
				$.post("http:localhost:8080/MyFirstDynamicWebProject/helloworld", $.toJSON({method : "test_load",para:"test"}), function(data) {
					var result = $.parseJSON(data);
					console.log("test post sucess!");
					console.log(result);

				});
			});
			
			function test_onclick(){
				$.post("http:localhost:8080/MyFirstDynamicWebProject/helloworld", $.toJSON({method : "test_button",para:"test button"}), function(data) {
					var result = $.parseJSON(data);
					console.log("test post sucess!");
					console.log(result);

				});				
			}
		
			
		</script>
	</head>
	<body>
		<p>servlet test</p>
		<p>This is a test html</p>
		<hr>
		<br>
		<input type="button" value="测试" onclick="test_onclick()" id="test_button"/>
		</form>
		
	</body>
</html>