如何嵌入Tomcat6？

Question

我目前正在Tomcat6上运行我的webapps，我想评估一下在嵌入式模式下运行Tomcat。

除了api documentation中的内容之外，还有没有好的教程或其他资源

Answer 1

代码不言而喻。请参阅pom.xml代码片段和运行tomcat的类。

    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>catalina</artifactId>
        <version>6.0.18</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>coyote</artifactId>
        <version>6.0.18</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>jasper</artifactId>
        <version>6.0.18</version>
        <scope>test</scope>
    </dependency>


public class RunWebApplicationTomcat {

    private String path = null;
    private Embedded container = null;
    private Log logger = LogFactory.getLog(getClass());

    /**
     * The directory to create the Tomcat server configuration under.
     */
    private String catalinaHome = "tomcat";

    /**
     * The port to run the Tomcat server on.
     */
    private int port = 8089;

    /**
     * The classes directory for the web application being run.
     */
    private String classesDir = "target/classes";

    /**
     * The web resources directory for the web application being run.
     */
    private String webappDir = "mywebapp";

    /**
     * Creates a single-webapp configuration to be run in Tomcat on port 8089. If module name does
     * not conform to the 'contextname-webapp' convention, use the two-args constructor.
     * 
     * @param contextName without leading slash, for example, "mywebapp"
     * @throws IOException
     */
    public RunWebApplicationTomcat(String contextName) {
        Assert.isTrue(!contextName.startsWith("/"));
        path = "/" + contextName;
    }

    /**
     * Starts the embedded Tomcat server.
     * 
     * @throws LifecycleException
     * @throws MalformedURLException if the server could not be configured
     * @throws LifecycleException if the server could not be started
     * @throws MalformedURLException
     */
    public void run(int port) throws LifecycleException, MalformedURLException {
        this.port = port;
        // create server
        container = new Embedded();
        container.setCatalinaHome(catalinaHome);
        container.setRealm(new MemoryRealm());

        // create webapp loader
        WebappLoader loader = new WebappLoader(this.getClass().getClassLoader());

        if (classesDir != null) {
            loader.addRepository(new File(classesDir).toURI().toURL().toString());
        }

        // create context
        // TODO: Context rootContext = container.createContext(path, webappDir);
        Context rootContext = container.createContext(path, webappDir);
        rootContext.setLoader(loader);
        rootContext.setReloadable(true);

        // create host
        // String appBase = new File(catalinaHome, "webapps").getAbsolutePath();
        Host localHost = container.createHost("localHost", new File("target").getAbsolutePath());
        localHost.addChild(rootContext);

        // create engine
        Engine engine = container.createEngine();
        engine.setName("localEngine");
        engine.addChild(localHost);
        engine.setDefaultHost(localHost.getName());
        container.addEngine(engine);

        // create http connector
        Connector httpConnector = container.createConnector((InetAddress) null, port, false);
        container.addConnector(httpConnector);

        container.setAwait(true);

        // start server
        container.start();

        // add shutdown hook to stop server
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                stopContainer();
            }
        });
    }
    /**
     * Stops the embedded Tomcat server.
     */
    public void stopContainer() {
        try {
            if (container != null) {
                container.stop();
            }
        } catch (LifecycleException exception) {
            logger.warn("Cannot Stop Tomcat" + exception.getMessage());
        }
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public static void main(String[] args) throws Exception {
        RunWebApplicationTomcat inst = new RunWebApplicationTomcat("mywebapp");
        inst.run(8089);
    }

    public int getPort() {
        return port;
    }

}

Answer 2

虽然这篇文章有些陈旧，但我是在回答我自己的答案，因为它可以节省别人的时间。

package com.creativefella;

import org.apache.catalina.Engine;
import org.apache.catalina.Host;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.startup.Embedded;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class TomcatServer {
    private Embedded server;
    private int port;
    private boolean isRunning;

    private static final Logger LOG = LoggerFactory.getLogger(TomcatServer.class);
    private static final boolean isInfo = LOG.isInfoEnabled();


/**
 * Create a new Tomcat embedded server instance. Setup looks like:
 * <pre><Server>
 *    <Service>
 *        <Connector />
 *        <Engine&gt
 *            <Host>
 *                <Context />
 *            </Host>
 *        </Engine>
 *    </Service>
 *</Server></pre>
 * <Server> & <Service> will be created automcatically. We need to hook the remaining to an {@link Embedded} instnace
 * @param contextPath Context path for the application
 * @param port Port number to be used for the embedded Tomcat server
 * @param appBase Path to the Application files (for Maven based web apps, in general: <code>/src/main/</code>)
 * @param shutdownHook If true, registers a server' shutdown hook with JVM. This is useful to shutdown the server
 *                      in erroneous cases.
 * @throws Exception
 */
    public TomcatServer(String contextPath, int port, String appBase, boolean shutdownHook) {
        if(contextPath == null || appBase == null || appBase.length() == 0) {
            throw new IllegalArgumentException("Context path or appbase should not be null");
        }
        if(!contextPath.startsWith("/")) {
            contextPath = "/" + contextPath;
        }

        this.port = port;

        server  = new Embedded();
        server.setName("TomcatEmbeddedServer");

        Host localHost = server.createHost("localhost", appBase);
        localHost.setAutoDeploy(false);

        StandardContext rootContext = (StandardContext) server.createContext(contextPath, "webapp");
        rootContext.setDefaultWebXml("web.xml");
        localHost.addChild(rootContext);

        Engine engine = server.createEngine();
        engine.setDefaultHost(localHost.getName());
        engine.setName("TomcatEngine");
        engine.addChild(localHost);

        server.addEngine(engine);

        Connector connector = server.createConnector(localHost.getName(), port, false);
        server.addConnector(connector);

        // register shutdown hook
        if(shutdownHook) {
            Runtime.getRuntime().addShutdownHook(new Thread() {
                public void run() {
                    if(isRunning) {
                        if(isInfo) LOG.info("Stopping the Tomcat server, through shutdown hook");
                        try {
                            if (server != null) {
                                server.stop();
                            }
                        } catch (LifecycleException e) {
                            LOG.error("Error while stopping the Tomcat server, through shutdown hook", e);
                        }
                    }
                }
            });
        }

    }

    /**
     * Start the tomcat embedded server
     */
    public void start() throws LifecycleException {
        if(isRunning) {
            LOG.warn("Tomcat server is already running @ port={}; ignoring the start", port);
            return;
        }

        if(isInfo) LOG.info("Starting the Tomcat server @ port={}", port);

        server.setAwait(true);
        server.start();
        isRunning = true;
    }

    /**
     * Stop the tomcat embedded server
     */
    public void stop() throws LifecycleException {
        if(!isRunning) {
            LOG.warn("Tomcat server is not running @ port={}", port);
            return;
        }

        if(isInfo) LOG.info("Stopping the Tomcat server");

        server.stop();
        isRunning = false;
    }

    public boolean isRunning() {
        return isRunning;
    }

}

我也遇到了404错误，并挣扎了一段时间。通过查看日志'INFO: No default web.xml'，我怀疑这是一个警告(如果这是一个警告，那么很容易被发现)。诀窍是使用Tomcat (conf/web.xml).提供的web.xml ( rootContext.setDefaultWebXml("web.xml") )原因是，它包括DefaultServlet，它提供静态文件，如HTML，JS。使用web.xml或在代码中手动注册servlet。

使用

// start the server at http://localhost:8080/myapp
TomcatServer server = new TomcatServer("myapp", 8080, "/src/main/", true);
server.start();
// .....
server.stop();

不要忘记将默认的 web.xml 放在此程序的同一目录中，或者指向正确的位置。

应该注意的是，关闭钩子的灵感来自于Antonio's answer。

Answer 3

使用Tomcat而不是Jetty的原因有很多：

Tomcat已经很熟悉Tomcat正在开发的installation

• The应用程序需要轻松移植到Tomcat开发人员文档实际上比Tomcat社区中回答的(amazing!)

• Getting问题还参差不齐，就像2007年一样。在Jetty6.1.*之后请参阅Embedding Jetty

• Important:，每个web应用程序都会打开到自己的JVM中，所以如果您试图在独立访问和web应用程序之间进行编程访问，那么您唯一的希望就是通过web API。

• 是一个开源项目，知识产权归阿帕奇基金会所有，

是开源项目，但归一家小型私人公司所有(Mortbay Consulting)

第五点在我的工作中一直很重要。例如，我可以通过Tomcat直接访问JSPWiki实例，但在使用Jetty时完全无法访问。我在2007年问过这个问题的解决方案，但还没有得到答复。所以我最终放弃了，开始使用Tomcat6。我研究了Glassfish和Grizzly，但到目前为止，Tomcat是(令人惊讶的)最稳定和文档最完善的web容器(这并不是很有说服力)。