java手动配置servlet文档详解

115 阅读 0 评论 76 点赞

我是靠谱客的博主机智金毛，这篇文章主要介绍java手动配置servlet文档详解，现在分享给大家，希望可以做个参考。

首先在tomcat服务器目录下的webapps目录下作为项目目录，我建立的是servlet,然后在这个目录下建立一个WEB-INF目录，能直接通过浏览器访问的资源都要放在WEB-INF目录外面，而WEB-INF目录是无法通过浏览器进行访问的。
然后在WEB-INF目录中建立classes和lib目录，lib目录是放相关类库的，classes目录就是servlet运行的目录，我们编写好的java源文件可以放到WEB-INF下，也可以自己定义一个存放源文件的目录，但是千万不要放在可以被访问到的地方。
然后我们复制web.xml文件（xml文件在下面），放在WEB-INF目录下，这样我们的目录就部署完毕了，然后我们编写简单的servlet源文件，代码如下：

复制代码

package zcc;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class servlet extends HttpServlet {

/**
		 * The doGet method of the servlet. <br>
		 *
		 * This method is called when a form has its tag value method equals to get.
		 * 
		 * @param request the request send by the client to the server
		 * @param response the response send by the server to the client
		 * @throws ServletException if an error occurred
		 * @throws IOException if an error occurred
		 */
	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
		out.println("<HTML>");
		out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
		out.println("  <BODY>");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the GET method");
		out.println("  </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

/**
		 * The doPost method of the servlet. <br>
		 *
		 * This method is called when a form has its tag value method equals to post.
		 * 
		 * @param request the request send by the client to the server
		 * @param response the response send by the server to the client
		 * @throws ServletException if an error occurred
		 * @throws IOException if an error occurred
		 */
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
		out.println("<HTML>");
		out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
		out.println("  <BODY>");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the POST method");
		out.println("  </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
package zcc;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class servlet extends HttpServlet {

	/**
		 * The doGet method of the servlet. <br>
		 *
		 * This method is called when a form has its tag value method equals to get.
		 * 
		 * @param request the request send by the client to the server
		 * @param response the response send by the server to the client
		 * @throws ServletException if an error occurred
		 * @throws IOException if an error occurred
		 */
	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
		out.println("<HTML>");
		out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
		out.println("  <BODY>");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the GET method");
		out.println("  </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

	/**
		 * The doPost method of the servlet. <br>
		 *
		 * This method is called when a form has its tag value method equals to post.
		 * 
		 * @param request the request send by the client to the server
		 * @param response the response send by the server to the client
		 * @throws ServletException if an error occurred
		 * @throws IOException if an error occurred
		 */
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
		out.println("<HTML>");
		out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
		out.println("  <BODY>");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the POST method");
		out.println("  </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

}

注意：这个java源文件是不能直接用javac编译的，原因是因为我们没有添加servlet的jar包，有两种方法来配置编译环境
第一个方法是让之前配置过JDK去加载jar包进行编译，我们复制tomcat服务器目录下lib目录中的servlet-api.jar文件，复制到之前配置好的%JAVA_HOME%jrelibext下，如下图：
在这里插入图片描述

　第二种方法是，还可以在之前配置好的环境变量CLASSPATH最后追加servlet-api.jar的路径，比如我的是：;%CATALINA_HOME%libservlet-api.jar，然后确定即可生效，这两种方法都可以，但是推荐第一种，因为jar包复制过去，以后服务器目录改变了也不影响

然后我们就可以直接编译java源文件了，我使用的编码是UTF-8(全世界通用的字符编码)，所以用：javac -encoding utf-8 HelloServlet.java进行编译
那么编译成功，同目录下会出现一个HelloServlet.class的字节码文件，然后我们复制该文件到classes/zcc/下，就是路径要和package声明包的保持一致，然后配置web.xml文件，当然在Servlet3.0之后还可以用注解进行url配置，xml文件内容如下：

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
  <servlet>
    <servlet-name>servlet</servlet-name>
    <display-name>This is the display name of my J2EE component</display-name>
    <description>This is the description of my J2EE component</description>
    <servlet-class>zcc.servlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>servlet</servlet-name>
    <url-pattern>/servlet/servlet</url-pattern>
  </servlet-mapping>

</web-app>