how tomcat works 5 servlet容器 下

标签：tomcat   读书笔记   servlet   源码   

Context应用程序

package org.apache.catalina;
public interface Mapper {
public Container getContainer();
public void setContainer(Container container);
public String getProtocol();
public void setProtocol(String protocol);
public Container map(Request request, boolean update);
}

public class SimpleContext implements Context, Pipeline {

  public SimpleContext() {
    pipeline.setBasic(new SimpleContextValve());
  }

  protected HashMap<String, Container> children = new HashMap<String, Container>();
  protected Loader loader = null;
  protected SimplePipeline pipeline = new SimplePipeline(this);
  protected HashMap<String, String> servletMappings = new HashMap<String, String>();
  protected Mapper mapper = null;
  protected HashMap<String, Mapper> mappers = new HashMap<String, Mapper>();
  private Container parent = null;
  ......
}

public final class Bootstrap2 {
    
@SuppressWarnings("deprecation")
public static void main(String[] args) {
    HttpConnector connector = new HttpConnector();
    
    Wrapper wrapper1 = new SimpleWrapper();
    wrapper1.setName("Primitive");
    wrapper1.setServletClass("PrimitiveServlet");
    Wrapper wrapper2 = new SimpleWrapper();
    wrapper2.setName("Modern");
    wrapper2.setServletClass("ModernServlet");

    Context context = new SimpleContext();
    context.addChild(wrapper1);
    context.addChild(wrapper2);

    Valve valve1 = new HeaderLoggerValve();
    Valve valve2 = new ClientIPLoggerValve();

    ((Pipeline) context).addValve(valve1);
    ((Pipeline) context).addValve(valve2);

    Mapper mapper = new SimpleContextMapper();
    mapper.setProtocol("http");
    context.addMapper(mapper);
    
    Loader loader = new SimpleLoader();
    context.setLoader(loader);
    // context.addServletMapping(pattern, name);
    context.addServletMapping("/Primitive", "Primitive");
    context.addServletMapping("/Modern", "Modern");
    connector.setContainer(context);
    try {
      connector.initialize();
      connector.start();

      // make the application wait until we press a key.
      System.in.read();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}

我们先看看时序图

public void invoke(Request request, Response response, ValveContext valveContext)
    throws IOException, ServletException {
 
   .....

    Context context = (Context) getContainer();
    // Select the Wrapper to be used for this Request
    Wrapper wrapper = null;
    try {
      wrapper = (Wrapper) context.map(request, true);            
    }
    catch (IllegalArgumentException e) {
      badRequest(requestURI, (HttpServletResponse) response.getResponse());
      return;
    }
    if (wrapper == null) {
      notFound(requestURI, (HttpServletResponse) response.getResponse());
      return;
    }
    // Ask this Wrapper to process this Request
    response.setContext(context);
    wrapper.invoke(request, response);
  }

  public Container map(Request request, boolean update) {
    //this method is taken from the map method in org.apache.cataline.core.ContainerBase
    //the findMapper method always returns the default mapper, if any, regardless the
    //request's protocol
    Mapper mapper = findMapper(request.getRequest().getProtocol());
    if (mapper == null)
      return (null);

    // Use this Mapper to perform this mapping
    return (mapper.map(request, update));
  }

  public Mapper findMapper(String protocol) {
    // the default mapper will always be returned, if any,
    // regardless the value of protocol
    if (mapper != null)
      return (mapper);
    else
      synchronized (mappers) {
        return ((Mapper) mappers.get(protocol));
      }
  }

how tomcat works 5 servlet容器 下

标签：tomcat   读书笔记   servlet   源码   

原文地址：http://blog.csdn.net/dlf123321/article/details/40211945