tomcat

@WebServlet

• @WebServlet 是servlet 3.0的写法
• 新建maven项目，结构如下

• pom文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.adagio</groupId><artifactId>tomcat-demo</artifactId><version>0.0.1-SNAPSHOT</version><packaging>war</packaging><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>Javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency><dependency><groupId>org.apache.tomcat.maven</groupId><artifactId>tomcat7-maven-plugin</artifactId><version>2.1</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>2.3.2</version><configuration><source>1.8</source><target>1.8</target></configuration></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-war-plugin</artifactId><version>3.2.0</version><configuration><failOnMissingWebXml>false</failOnMissingWebXml></configuration></plugin></plugins></build>
</project>

• Java Code

package com.adagio;import java.io.IOException;import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@WebServlet(urlPatterns = "/demo")
public class DemoServlet extends HttpServlet {private static final long serialVersionUID = 1L;public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;charset=UTF-8");String message = request.getParameter("message");response.getWriter().print(message);response.getWriter().println("<br/>");}}

• 打包：mvn -Dmaven.test.skip -U clean package
• 启动：war包放到tomcat/webapps目录下，启动tomcat
• 访问：http://localhost:8080/tomcat-demo-0.0.1-SNAPSHOT/demo?message=hello

使用maven插件，构建嵌入式容器

• POM文件中添加

<plugin><groupId>org.apache.tomcat.maven</groupId><artifactId>tomcat7-maven-plugin</artifactId><version>2.1</version><executions><execution><id>tomcat-run</id><goals><goal>exec-war-only</goal></goals><phase>package</phase><configuration><!-- ServletContext path --><path>/</path></configuration></execution></executions></plugin>

• 打包：mvn -Dmaven.test.skip -U clean package
• 启动：java -jar targettomcat-demo-0.0.1-SNAPSHOT-war-exec.jar
• 访问：http://localhost:8080/demo?message=hello
• 解压jar包，找到 META-INF/MANIFEST.MF

Manifest-Version: 1.0
Main-Class: org.apache.tomcat.maven.runner.Tomcat7RunnerCli

• 可以得出jar 的启动类：org.apache.tomcat.maven.runner.Tomcat7RunnerCli

模拟server.xml，构建嵌入式容器

源码

import java.io.File;import org.apache.catalina.Context;
import org.apache.catalina.Host;
import org.apache.catalina.Service;
import org.apache.catalina.Wrapper;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.startup.Tomcat;/*** 访问 ： http://localhost:9527/index.jsp* http://localhost:9527/demo?message=hello**/
public class EmbeddedTomcatServer {public static void main(String[] args) throws Exception {//确定classes 目录绝对路径String calssesPath = System.getProperty("user.dir") + File.separator + "target" + File.separator + "classes";System.out.println(calssesPath);//创建Tomcat实例Tomcat tomcat = new Tomcat();tomcat.setPort(9527);//设置HostHost host = tomcat.getHost();host.setName("localhost");host.setAppBase("webapps");//设置 Context//server.xml - <Context docBase="" path="/" /></Host>String webapp = System.getProperty("user.dir") + File.separator+ "src" + File.separator + "main" + File.separator + "webapp";String contextPath = "/";//设置 webapp 绝对路径到 Context，作为它的docBaseContext context = tomcat.addWebapp(contextPath, webapp);if(context instanceof StandardContext) {StandardContext standardContext = new StandardContext();// 设置默认的web.xml文件到ContextstandardContext.setDefaultContextXml(calssesPath + File.separator + "conf/web.xml");//设置 Classpath 到Context// 添加DemoServlet到tomcat 容器Wrapper wrapper = tomcat.addServlet(contextPath, "DemoServlet", new DemoServlet());wrapper.addMapping("/demo");}//http://localhost:9526/demo?message=%E5%B0%8F%E9%A9%AC//设置ServiceService service = tomcat.getService();Connector connector = new Connector();//这里设置了一个port，等于两个端口都可以使用，但是上面那个端口访问中文乱码connector.setPort(9526);connector.setURIEncoding("UTF-8");connector.setProtocol("HTTP/1.1");service.addConnector(connector);//启动 tomcat 服务器tomcat.start();        // 强制 Tomcat Server 等待，避免main线程执行结束关闭tomcat.getServer().await();}
}

文件

• 直接从tomcat/conf copy web.xml到项目中
• 在resources下建 conf目录，把copy的web.xml放进去
• 在webapp下新建 index.jsp
• 具体如图

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