Tomcat 学习笔记

1 Tomcat的使用

下载安装

1 下载地址: https://tomcat.apache.org/download-90.cgi
2 下载内容

3 下载后解压到/Library目录下
4 修改目录权限

sudo chmod 755 *.sh
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启动

1 cd到tomcat安装目录下启动tomcat

cd /Library/apache-tomcat-9.0.68/bin
sudo sh ./startup.sh
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2 启动后，在浏览器中输入localhost:8080即可访问到tomcat

关闭

sudo sh ./shutdown.sh
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配置

可以在conf/server.xml中修改端口号

<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
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部署

将html文件拷贝到webapps目录下，然后访问http://localhost:8080/test.html，将会访问到部署到webapps中的内容

2 Idea创建tomcat工程

1 选择moven工程

点选创建骨架，选择webapp，最后选next

2 输入工程名

3 配置pom.xml

选择next，finish，最后pom.xml中的冗余配置，最终配置如下

<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>4.0.0modelVersion>

  <groupId>org.examplegroupId>
  <artifactId>Tomcat-TestartifactId>
  <version>1.0-SNAPSHOTversion>
  <packaging>warpackaging>

project>
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4 补全目录结构

5 安装Maven Helper插件

6 启动tomcat

启动成功后即可访问本地资源

http://localhost:8080/tomcat-demo
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3 Servlet

3.1 Servlet的使用

1 引入Servlet依赖

<dependencies>
    <dependency>
        <groupId>javax.servletgroupId>
        <artifactId>javax.servlet-apiartifactId>
        <version>3.1.0version>
        <scope>providedscope>
    dependency>
dependencies>
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2 添加实现Servelet接口的子类

@WebServlet("/demo1")
public class ServletDemo implements Servlet {
    public void init(ServletConfig servletConfig) throws ServletException {

    }

    public ServletConfig getServletConfig() {
        return null;
    }

    public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
        System.out.println("德玛西亚必胜!");
    }

    public String getServletInfo() {
        return null;
    }

    public void destroy() {

    }
}
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3 启动tomcat，然后访问资源

http://localhost:8080/tomcat-demo/demo1
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可以看到控制台输出了在service()方法中打印的日志

3.2 生命周期

1 在init()，service(), destroy()方法中添加日志

@WebServlet("/demo1")
public class ServletDemo implements Servlet {
    public void init(ServletConfig servletConfig) throws ServletException {
        System.out.println("init()");
    }

    public ServletConfig getServletConfig() {
        return null;
    }

    public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
        System.out.println("service()");
    }

    public String getServletInfo() {
        return null;
    }

    public void destroy() {
        System.out.println("destroy()");
    }
}
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2 在ternimal中运行命令

mvn tomcat7:run
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遇到如下报错

[ERROR] No plugin found for prefix 'tomcat7' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/yl/.m2/repository), central (https://repo.maven.apache.org/maven2)] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/NoPluginFoundForPrefixException
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这是因为当前的Terminal目录没有切换到真正的工程目录下
切换到工程目录下后，访问资源地址

http://localhost:8080/demo1
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此时，控制台输出日志

init()
service()
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按control + c退出后,输出日志

destroy()
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3.3 doGet/doPost

1 doGet请求

@WebServlet("/demo2")
public class Servlet2Demo extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("doGet");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("doPost");
    }
}
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此时访问

http://localhost:8080/tomcat-demo/demo2
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将会输出日志doGet

2 doPost请求
创建html文件

DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Titletitle>
head>
<body>
    <form action="/tomcat-demo/demo2" method="post">
        <input name="username"/>
        <input type="submit"/>
    form>
body>
html>
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访问html资源

http://localhost:8080/tomcat-demo/test.html
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将会看到doPost()日志

3.4 urlPattern配置

1 配置多个urlPattern

@WebServlet(urlPatterns = {"/demo3", "/demo4"})
public class Servlet7 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }
}
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此时访问
http://localhost:8080/tomcat-demo/demo3
http://localhost:8080/tomcat-demo/demo4
都能匹配到

2 精确匹配

@WebServlet(urlPatterns = "/api/select")
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对应的url

http://localhost:8080/tomcat-demo/api/select
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3 目录匹配

@WebServlet(urlPatterns = "/api/*")
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对应的url,api后可以填任意值

http://localhost:8080/tomcat-demo/api/any
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4 任意匹配

@WebServlet(urlPatterns = "/*")
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访问的url可以填任意内容

http://localhost:8080/tomcat-demo/test
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3.5 xml配置

servlet

public class Servlet3Demo extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Servlet3Demo#doGet()");
    }
}
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web.xml配置

DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Applicationdisplay-name>
  <servlet>
    <servlet-name>demo3servlet-name>
    <servlet-class>com.test.tomcat.Servlet3Demoservlet-class>
  servlet>

  <servlet-mapping>
    <servlet-name>demo3servlet-name>
    <url-pattern>/demo3url-pattern>
  servlet-mapping>
web-app>

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访问此接口的url

http://localhost:8080/tomcat-demo/demo3
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