Servlet的初次体验

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Servlet存在于javax.servlet.http.HttpServlet包中

Servlet的关键实现类

image-20220415002429581

一般我们使用继承HttpServlet

注册Servlet

servlet需要在web.xml完成相应的注册

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<!--注册servlet-->
<servlet>
    <servlet-name>hello</servlet-name>
    <servlet-class>io.anran0.servler.HelloServler</servlet-class>
</servlet>

<!--servlet的请求路径-->
<servlet-mapping>
    <servlet-name>hello</servlet-name>
    <url-pattern>/hello</url-pattern>
</servlet-mapping>

image-20220415002728543

java-demo

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package io.anran0.servler;


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

public class HelloServler extends HttpServlet {


    //Request请求头
    //Response响应头
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
        System.out.println("HelloServler.doGet4");
        
//        ServletOutputStream outputStream = resp.getOutputStream();
        
        resp.setContentType("text/html");
        resp.setCharacterEncoding("utf-8");
        
        PrintWriter writer = resp.getWriter();
        String s = "你好hello,hervlet" + new Random().nextInt();
        writer.print(s);
    }

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

}