The Servlet of actual combat

Generally in the actual project development, is the use of inheritance HttpServlet class method to achieve the Servlet program.

Implementation steps:

  1. Create a Web project to import Servlet dependencies
  2. Write a class to implement the HttpServlet class
  3. Override the doGet or doPost methods based on business needs
  4. Configure the Servlet access address in web.xml.

1. Create a Web project and import Servlet dependencies

How do I add Web components to a project?

Project right click ->Add Framework Support…

–> Select the Web application

The Servlet rely on

< the dependency > < groupId > javax.mail. Servlet < / groupId > < artifactId > javax.mail. The servlet API - < / artifactId > < version > 3.1.0 < / version > </dependency> <! -- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api --> <dependency> < < the groupId > javax.mail. Servlet. JSP/groupId > < artifactId > javax.mail. Servlet. JSP - API < / artifactId > < version > 2.3.3 < / version > </dependency>Copy the code

Write a class that inherits HttpServlet

3. Override the doGet or doPost method as required

public class MyServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { //1. String method = req.getParameter("method"); If (method.equals("add")) {req.getSession().setAttribute(" MSG "," executed the add method "); } if (method.equals("delete")) {req.getSession().setAttribute(" MSG "," execute delete method "); Req. GetRequestDispatcher ("/ web-INF/JSP /test.jsp").forward(req,resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doGet(req,resp); }}Copy the code

4. Configure the Servlet access address in web. XML

<? The XML version = "1.0" encoding = "utf-8"? > <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" Version = "4.0" > < servlet > < servlet - name > hello < / servlet - name > <! --> <servlet-class> com.bewind.myservlet </servlet-class> </servlet-class> </ servlet-mapping> <servlet-name>hello</servlet-name> <url-pattern>/hello</url-pattern> </servlet-mapping> <! -- Welcome page --> <! --<welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list>--> </web-app>Copy the code

Configuring the Server

See the Tomcat of actual combat

Normal execution

The above code no request so visit http://localhost:8080/ServletCombat_war_exploded/hello

complains