Java Web基础之Servlet入门

package com.imooc.servlet;

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 FirstServlet extends HttpServlet {

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// 接受请求发来的参数
		String name = request.getParameter("name");
		String html = "<h1 style='color:red'>hi," + name + "!</h1><hr/>";
		PrintWriter out = response.getWriter();
		out.println(html);// 将html发送回浏览器
	}

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FirstServlet</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 声明servlet -->
  <servlet>
  	<!-- servlet的别名 -->
  	<servlet-name>first</servlet-name>
  	<servlet-class>com.imooc.servlet.FirstServlet</servlet-class>
  </servlet>
  <!-- 将servlet与url绑定 -->
  <servlet-mapping>
  	<servlet-name>first</servlet-name>
  	<url-pattern>/hi</url-pattern>
  </servlet-mapping>
</web-app>
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<form action="/FirstServlet/sample">
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public void doGet(HttpServletRequest request, HttpServletResponse response){//处理get请求
处理post请求就是doPost
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import javax.servlet.annotation.WebServlet;

@WebServlet("/anno")
public class Annotation extends HttpServlet{

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		resp.getWriter().println("11");
	}
}
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0的执行级别最高

package com.imooc.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

public class create extends HttpServlet{

	@Override
	public void init() throws ServletException {
		System.out.println("哈哈哈哈哈");
	}
}


<servlet>
  	<servlet-name>create</servlet-name>
  	<servlet-class>com.imooc.servlet.create</servlet-class>
  	<load-on-startup>0</load-on-startup>
</servlet>
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第二种办法，不需要配置xml

@WebServlet(urlPatterns="/cr",loadOnStartup=0)
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