实现servlet的三种方式

实现Servlet接口

实现Serclet接口并重写五个方法：

• void init(ServletConfig config)
• void destroy()
• void service(ServletRequest request, ServletResponse response)
• String getServletInfo()
• ServletConfig getServletConfig()

示例代码：

package com.hitmt.servlet;

import java.io.IOException;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;

/**
 * 
Description: 通过实现Servlet接口，从而实现Servlet的演示
 * @author HiTMT
 * @date 2019年10月12日上午12:30:36  
 */
@WebServlet("/MyServlet")
public class MyServlet implements Servlet {

	@Override
	public void destroy() {
		System.out.println("MyServlet被销毁了");
	}

	@Override
	public ServletConfig getServletConfig() {
		return null;
	}

	@Override
	public String getServletInfo() {
		return null;
	}

	@Override
	public void init(ServletConfig config) throws ServletException {
		System.out.println("配置信息："+config);
	}

	@Override
	public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
		response.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().write("Hello World");
	}
	
}

继承GenericServlet类

继承GenericServlet类并重写一个方法：

• void service(ServletRequest request, ServletResponse response)

示例代码：

package com.hitmt.servlet;

import java.io.IOException;

import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;

/**
 * 
Description: 通过继承GenericServlet实现Servlet的演示
 * @author HiTMT
 * @date 2019年10月12日上午12:30:24  
 */
@WebServlet("/MyGenericServlet")
public class MyGenericServlet extends GenericServlet {
	
	@Override
	public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
		response.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().write("Hello World");
	}

}

继承HttpServlet类

继承GenericServlet类并可重写两个方法：

• void doGet(HttpServletRequest req, HttpServletResponse resp)
• void doPost(HttpServletRequest req, HttpServletResponse resp)

示例代码：

package com.hitmt.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;

/**
 * 
Description: 通过继承HttpServlet实现Servlet的演示
 * @author HiTMT
 * @date 2019年10月12日上午12:29:45  
 */
@WebServlet("/MyHttpServlet")
public class MyHttpServlet extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		resp.setCharacterEncoding("utf-8");
		resp.setContentType("text/html;charset=utf-8");
		resp.getWriter().write("Hello World");
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doGet(req, resp);
	}

}