Embed Tomcat Java(内嵌tomcat启动简述)

简单记录一下内部tomcat启动

maven pom.xml

	<dependencies>

		<!-- embed tomcat dependency -->

		<dependency>

			<groupId>org.apache.tomcat.embed</groupId>

			<artifactId>tomcat-embed-core</artifactId>

			<version>8.5.28</version>

		</dependency>

		<dependency>

			<groupId>org.apache.tomcat</groupId>

			<artifactId>tomcat-jasper</artifactId>

			<version>8.5.28</version>

		</dependency>

		<!-- spring dependency -->

		<dependency>

			<groupId>org.springframework</groupId>

			<artifactId>spring-web</artifactId>

			<version>5.0.4.RELEASE</version>

			<scope>compile</scope>

		</dependency>

		<dependency>

			<groupId>org.springframework</groupId>

			<artifactId>spring-webmvc</artifactId>

			<version>5.0.4.RELEASE</version>

			<scope>compile</scope>

		</dependency>

	</dependencies>

	<build>

		<plugins>

			<!-- 添加编译插件 -->

			<plugin>

				<groupId>org.apache.maven.plugins</groupId>

				<artifactId>maven-compiler-plugin</artifactId>

				<version>3.5.1</version>

				<configuration>

					<source>1.8</source>

					<target>1.8</target>

					<encoding>UTF-8</encoding>

				</configuration>

			</plugin>

		</plugins>

	</build>

tomcat启动类

/**

 *

 * @author Programming is an art from.

 * @Description: TODO

 */

public class TomcatStart {

    public static int TOMCAT_PORT = 8080;

    public static String TOMCAT_HOSTNAME = "127.0.0.1";

    public static String WEBAPP_PATH = "src/main";

    public static String WEBINF_CLASSES = "/WEB-INF/classes";

    public static String CLASS_PATH = "target/classes";

    public static String INTERNAL_PATH = "/";

    public static void main(String[] args) throws ServletException, LifecycleException {

        TomcatStart.run();

    }

    public static void run() throws ServletException, LifecycleException {

        Tomcat tomcat = new Tomcat();

        tomcat.setPort(TomcatStart.TOMCAT_PORT);

        tomcat.setHostname(TomcatStart.TOMCAT_HOSTNAME);

        tomcat.setBaseDir("."); // tomcat 信息保存在项目下

        /*

         * https://www.cnblogs.com/ChenD/p/10061008.html

         */

        StandardContext myCtx = (StandardContext) tomcat

            .addWebapp("/access", System.getProperty("user.dir") + File.separator + TomcatStart.WEBAPP_PATH);

        /*

         * true时：相关classes | jar 修改时，会重新加载资源，不过资源消耗很大

         * autoDeploy 与这个很相似，tomcat自带的热部署不是特别可靠，效率也不高。生产环境不建议开启。

         * 相关文档：

         * http://www.blogjava.net/wangxinsh55/archive/2011/05/31/351449.html

         */

        myCtx.setReloadable(false);

        // 上下文监听器

        myCtx.addLifecycleListener(new AprLifecycleListener());

        /*String webAppMount = System.getProperty("user.dir") + File.separator + TomcatStart.CLASS_PATH;

        WebResourceRoot root = new StandardRoot(myCtx);

        root.addPreResources(

            new DirResourceSet(root, TomcatStart.WEBINF_CLASSES, webAppMount, TomcatStart.INTERNAL_PATH));*/

        // 注册servlet

        tomcat.addServlet("/access", "demoServlet", new DemoServlet());

        // servlet mapping

        myCtx.addServletMappingDecoded("/demo.do", "demoServlet");

        tomcat.start();

        tomcat.getServer().await();

    }

}

警告: A context path must either be an empty string or start with a '/' and do not end with a '/'. The path [/] does not meet these criteria and has been changed to []

Exception in thread "main" java.lang.NullPointerException

	at org.apache.catalina.startup.Tomcat.addServlet(Tomcat.java:341)

	at org.apache.catalina.startup.Tomcat.addServlet(Tomcat.java:325)

	at cn.learn.config.TomcatStart.run(TomcatStart.java:63)

	at cn.learn.config.TomcatStart.main(TomcatStart.java:33)

servlet class

/**

 *

 * @author Programming is an art from.

 * @Description: TODO

 */

public class DemoServlet extends HttpServlet{

    /**

     *

     */

    private static final long serialVersionUID = 1L;

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        doPost(req, resp);

    }

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        resp.getWriter().print("access success!!!");

    }

}