Java Servlet HelloWorld

亦凉 2022-06-07 13:54 128阅读 0赞

创建一个基于Maven 的 Servlet HelloWorld程序。

# 程序代码 #

## pom.xml ##

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>com.jeiker.demo</groupId>
      <artifactId>servlet-hello</artifactId>
      <packaging>war</packaging>
      <version>1.0-SNAPSHOT</version>
    
      <name>servlet-hello Maven Webapp</name>
      <url>http://maven.apache.org</url>
    
      <dependencies>
    
        <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>javax.servlet-api</artifactId>
          <version>3.0.1</version>
          <scope>provided</scope>
        </dependency>
    
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
    
      </dependencies>
    
      <build>
        <finalName>servlet-hello</finalName>
    
        <plugins>
    
          <plugin>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-maven-plugin</artifactId>
            <version>9.2.11.v20150529</version>
            <configuration>
              <reload>automatic</reload>
              <scanIntervalSeconds>1</scanIntervalSeconds>
              <webApp>
                <contextPath>/</contextPath>
              </webApp>
            </configuration>
          </plugin>
    
        </plugins>
    
      </build>
    </project>

## HelloServlet.java ##

继承 HttpServlet，重写 doGet 和 doPost 方法。

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;
    
    /** * @author : xiao * @date : 17/10/23 下午4:28 * @description : */
    public class HelloServlet extends HttpServlet {
    
        @Override
        public void doGet(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {
    
            response.setContentType("text/html");
            PrintWriter out = response.getWriter();
            out.println("<!DOCTYPE html>");
            out.println("<html lang=\"en\">");
            out.println("<head>");
            out.println(" <meta charset=\"UTF-8\">");
            out.println(" <title>HelloServlet</title>");
            out.println("</head>");
            out.println("<body>");
            out.println(" <h4>hello world! </h4>");
            out.println(" <p>This is class " + this.getClass() + " , using the GET method!</p>");
            out.println("</body>");
            out.println("</html>");
            out.flush();
            out.close();
        }
    
        @Override
        public void doPost(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {
    
            response.setContentType("text/html");
            PrintWriter out = response.getWriter();
            out.println("<!DOCTYPE html>");
            out.println("<html lang=\"en\">");
            out.println("<head>");
            out.println(" <meta charset=\"UTF-8\">");
            out.println(" <title>HelloServlet</title>");
            out.println("</head>");
            out.println("<body>");
            out.println(" <h4>hello world! </h4>");
            out.println(" <p>This is class " + this.getClass() + " , using the POST method!</p>");
            out.println("</body>");
            out.println("</html>");
            out.flush();
            out.close();
        }
    }

## web.xml ##

<web-app>
      <display-name>Archetype Created Web Application</display-name>
    
      <servlet>
        <servlet-name>Hello</servlet-name>
        <servlet-class>com.jeiker.demo.HelloServlet</servlet-class>
      </servlet>
    
      <servlet-mapping>
        <servlet-name>Hello</servlet-name>
        <url-pattern>/servlet/hello</url-pattern>
      </servlet-mapping>
    
    </web-app>

# 测试 #

启动项目

mvn jetty:run

*  GET: [http://localhost:8080/servlet/hello][http_localhost_8080_servlet_hello]
 *  POST: [http://localhost:8080/servlet/hello][http_localhost_8080_servlet_hello]

![这里写图片描述][SouthEast]

![这里写图片描述][SouthEast 1]

[http_localhost_8080_servlet_hello]: http://localhost:8080/servlet/hello
[SouthEast]: /images/20220607/d3493ca1362a446c8f6a7e9a418b6eba.png
[SouthEast 1]: /images/20220607/f6d5e9941d0d4b12b3c1ccdb51a68539.png