嵌入式Tomcat

下面为嵌入使用Tomcat的示例代码：

import java.net.URL;

import org.apache.catalina.Context;
import org.apache.catalina.core.AprLifecycleListener;
import org.apache.catalina.core.StandardServer;
import org.apache.catalina.deploy.FilterDef;
import org.apache.catalina.deploy.FilterMap;
import org.apache.catalina.startup.Tomcat;
import org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter;

import com.beust.jcommander.JCommander;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.servlet.GuiceFilter;

public class WebServer {

  private final FrontendSettings webServerSettings;
  private final GuiceListener guiceListener;
  private final Tomcat tomcat;

  @Inject
  public WebServer(
      FrontendSettings webServerSettings,
      GuiceListener guiceListener) {
    this.webServerSettings = webServerSettings;
    this.guiceListener = guiceListener;
    this.tomcat = new Tomcat();
  }

  private FilterDef createFilterDef(String filterName, String filterClass) {
    FilterDef filterDef = new FilterDef();
    filterDef.setFilterName(filterName);
    filterDef.setFilterClass(filterClass);
    return filterDef;
  }
  
  private FilterMap createFilterMap(String filterName, String urlPattern) {
    FilterMap filterMap = new FilterMap();
    filterMap.setFilterName(filterName);
    filterMap.addURLPattern(urlPattern);
    return filterMap;
  }
  
  public void run() throws Exception {
    String appBase = ".";
    tomcat.setPort(webServerSettings.getPort());

    tomcat.setBaseDir("webapp");
    tomcat.getHost().setAppBase(appBase);

    String contextPath = "/";

    // Add AprLifecycleListener to give native speed boost
    // sudo apt-get install libtcnative-1
    StandardServer server = (StandardServer)tomcat.getServer();
    AprLifecycleListener listener = new AprLifecycleListener();
    server.addLifecycleListener(listener);

    Context context = tomcat.addWebapp(contextPath, appBase);
    context.addFilterDef(createFilterDef("guice", GuiceFilter.class.getName()));
    FilterDef struts2FilterDef = createFilterDef("struts2",
        StrutsPrepareAndExecuteFilter.class.getName());
    struts2FilterDef.addInitParameter("struts.devMode",
        Boolean.toString(webServerSettings.isDevModeEnabled()));
    context.addFilterDef(struts2FilterDef);
    context.addFilterMap(createFilterMap("guice", "/*"));
    context.addFilterMap(createFilterMap("struts2", "/*"));
    
    tomcat.start();
    tomcat.getServer().await();
  }

  public static void main(String[] args) throws Exception {
    FrontendSettings webServerSettings = new FrontendSettings();
    new JCommander(webServerSettings, args);
    
    Guice.createInjector(new FrontendModule(webServerSettings));
    
    Injector injector = Guice.createInjector();
    
    WebServer server = injector.getInstance(WebServer.class);
    server.run();
  }

}