1、servlet间的请求转发
?<dependencies> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>javax.servlet-api</artifactId> ?????<version>3.1.0</version> ?????<scope>provided</scope> ???</dependency> ?</dependencies> ?<build> ???<finalName>servlet-demo</finalName> ???<plugins> ?????<plugin> ???????<groupId>org.mortbay.jetty</groupId> ???????<artifactId>jetty-maven-plugin</artifactId> ???????<version>8.1.16.v20140903</version> ???????<configuration> ?????????<scanIntervalSeconds>10</scanIntervalSeconds> ?????????<connectors> ???????????<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector"> ?????????????<port>7777</port> ???????????</connector> ?????????</connectors> ?????????<webAppConfig> ???????????<contextPath>/</contextPath> ?????????</webAppConfig> ???????</configuration> ?????</plugin> ???</plugins> ?</build>
package com.test;import javax.servlet.RequestDispatcher;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebServlet("/myServlet")public class MyServlet extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????RequestDispatcher requestDispatcher = request.getRequestDispatcher("myServlet2"); ???????requestDispatcher.forward(request, response); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}package com.demo;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebServlet("/myServlet2")public class MyServlert2 extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????response.getWriter().write("I am Servlet2"); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}myServlet和myServlet2在不同的包，但请求转发时不需要使用—— ../ 之类的相对路径，会自动寻找到适合的Servlet
2、servlet转发到jsp
?<dependencies> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>javax.servlet-api</artifactId> ?????<version>3.1.0</version> ?????<scope>provided</scope> ???</dependency> ?</dependencies> ?<build> ???<finalName>servlet-demo</finalName> ???<plugins> ?????<plugin> ???????<groupId>org.mortbay.jetty</groupId> ???????<artifactId>jetty-maven-plugin</artifactId> ???????<version>8.1.16.v20140903</version> ???????<configuration> ?????????<scanIntervalSeconds>10</scanIntervalSeconds> ?????????<connectors> ???????????<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector"> ?????????????<port>7777</port> ???????????</connector> ?????????</connectors> ?????????<webAppConfig> ???????????<contextPath>/</contextPath> ?????????</webAppConfig> ???????</configuration> ?????</plugin> ???</plugins> ?</build>
package com.test;import javax.servlet.RequestDispatcher;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebServlet("/myServlet")public class MyServlet extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????RequestDispatcher requestDispatcher = request.getRequestDispatcher("/WEB-INF/my.jsp"); ???????requestDispatcher.forward(request, response); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}<html><body><h2>Hello World! I am Mike</h2></body></html>
3、jsp里使用java代码转发到servlet
?<dependencies> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>javax.servlet-api</artifactId> ?????<version>3.1.0</version> ?????<scope>provided</scope> ???</dependency> ???<dependency> ?????<groupId>javax.servlet.jsp</groupId> ?????<artifactId>javax.servlet.jsp-api</artifactId> ?????<version>2.2.1</version> ?????<scope>provided</scope> ???</dependency> ?</dependencies> ?<build> ???<finalName>servlet-demo</finalName> ???<plugins> ?????<plugin> ???????<groupId>org.mortbay.jetty</groupId> ???????<artifactId>jetty-maven-plugin</artifactId> ???????<version>8.1.16.v20140903</version> ???????<configuration> ?????????<scanIntervalSeconds>10</scanIntervalSeconds> ?????????<connectors> ???????????<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector"> ?????????????<port>7777</port> ???????????</connector> ?????????</connectors> ?????????<webAppConfig> ???????????<contextPath>/</contextPath> ?????????</webAppConfig> ???????</configuration> ?????</plugin> ???</plugins> ?</build>
<%-- 下面的内容相当于写在service方法里 --%><% ???RequestDispatcher requestDispatcher = request.getRequestDispatcher("myServlet"); ???requestDispatcher.include(request, response);%>package com.test;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;@WebServlet("/myServlet")public class MyServlet extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????response.setContentType("text/html; charset=utf-8"); ???????PrintWriter out = response.getWriter(); ???????out.println("<p>How are you</p>"); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}4、jsp标准标签请求转发
?<dependencies> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>javax.servlet-api</artifactId> ?????<version>3.1.0</version> ?????<scope>provided</scope> ???</dependency> ???<dependency> ?????<groupId>javax.servlet.jsp</groupId> ?????<artifactId>javax.servlet.jsp-api</artifactId> ?????<version>2.2.1</version> ?????<scope>provided</scope> ???</dependency> ?</dependencies> ?<build> ???<finalName>servlet-demo</finalName> ???<plugins> ?????<plugin> ???????<groupId>org.mortbay.jetty</groupId> ???????<artifactId>jetty-maven-plugin</artifactId> ???????<version>8.1.16.v20140903</version> ???????<configuration> ?????????<scanIntervalSeconds>10</scanIntervalSeconds> ?????????<connectors> ???????????<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector"> ?????????????<port>7777</port> ???????????</connector> ?????????</connectors> ?????????<webAppConfig> ???????????<contextPath>/</contextPath> ?????????</webAppConfig> ???????</configuration> ?????</plugin> ???</plugins> ?</build>
<%! ???private String name = "Mike Chang";%><%-- 下面的内容相当于写在service方法里 --%><p>I am <%= name %></p><jsp:include page="myServlet"/>
package com.test;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;@WebServlet("/myServlet")public class MyServlet extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????response.setContentType("text/html; charset=utf-8"); ???????PrintWriter out = response.getWriter(); ???????out.println("<p>How are you</p>"); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}I am Mike ChangHow are you
5、jsp核心标签库请求转发
?<dependencies> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>javax.servlet-api</artifactId> ?????<version>3.1.0</version> ?????<scope>provided</scope> ???</dependency> ???<dependency> ?????<groupId>javax.servlet.jsp</groupId> ?????<artifactId>javax.servlet.jsp-api</artifactId> ?????<version>2.2.1</version> ?????<scope>provided</scope> ???</dependency> ???<dependency> ?????<groupId>javax.servlet</groupId> ?????<artifactId>jstl</artifactId> ?????<version>1.2</version> ???</dependency> ?</dependencies> ?<build> ???<finalName>servlet-demo</finalName> ???<plugins> ?????<plugin> ???????<groupId>org.mortbay.jetty</groupId> ???????<artifactId>jetty-maven-plugin</artifactId> ???????<version>8.1.16.v20140903</version> ???????<configuration> ?????????<scanIntervalSeconds>10</scanIntervalSeconds> ?????????<connectors> ???????????<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector"> ?????????????<port>7777</port> ???????????</connector> ?????????</connectors> ?????????<webAppConfig> ???????????<contextPath>/</contextPath> ?????????</webAppConfig> ???????</configuration> ?????</plugin> ???</plugins> ?</build>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%! ???private String name = "Mike";%><%-- 下面的内容相当于写在service方法里 --%><p>I am <%= name %></p><c:import url="myServlet"/>
package com.test;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;@WebServlet("/myServlet")public class MyServlet extends HttpServlet { ???public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????response.setContentType("text/html; charset=utf-8"); ???????PrintWriter out = response.getWriter(); ???????out.println("<p>How are you</p>"); ???} ???public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????doGet(request, response); ???}}servlet及jsp之间的请求转发
原文地址：https://www.cnblogs.com/Mike_Chang/p/10324904.html