Importing upstream Jetty jetty-9.2.1.v20140609

[gigi.git] / lib / jetty / org / eclipse / jetty / servlet / BaseHolder.java

diff --git a/lib/jetty/org/eclipse/jetty/servlet/BaseHolder.java b/lib/jetty/org/eclipse/jetty/servlet/BaseHolder.java
new file mode 100644 (file)
index 0000000..a32e1a6
--- /dev/null
+++ b/lib/jetty/org/eclipse/jetty/servlet/BaseHolder.java
@@ -0,0 +1,209 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.servlet;
+
+import java.io.IOException;
+
+import javax.servlet.ServletContext;
+import javax.servlet.UnavailableException;
+
+import org.eclipse.jetty.server.handler.ContextHandler;
+import org.eclipse.jetty.util.Loader;
+import org.eclipse.jetty.util.annotation.ManagedAttribute;
+import org.eclipse.jetty.util.component.AbstractLifeCycle;
+import org.eclipse.jetty.util.component.ContainerLifeCycle;
+import org.eclipse.jetty.util.component.Dumpable;
+import org.eclipse.jetty.util.log.Log;
+import org.eclipse.jetty.util.log.Logger;
+
+/**
+ * AbstractHolder
+ * 
+ * Base class for all servlet-related classes that may be lazily instantiated  (eg servlet, filter, 
+ * listener), and/or require metadata to be held regarding their origin 
+ * (web.xml, annotation, programmatic api etc).
+ * 
+ */
+public abstract class BaseHolder<T> extends AbstractLifeCycle implements Dumpable
+{
+    private static final Logger LOG = Log.getLogger(BaseHolder.class);
+    
+    
+    public enum Source { EMBEDDED, JAVAX_API, DESCRIPTOR, ANNOTATION };
+    
+    final protected Source _source;
+    protected transient Class<? extends T> _class;
+    protected String _className;
+    protected boolean _extInstance;
+    protected ServletHandler _servletHandler;
+    
+    /* ---------------------------------------------------------------- */
+    protected BaseHolder(Source source)
+    {
+        _source=source;
+    }
+
+    /* ------------------------------------------------------------ */
+    public Source getSource()
+    {
+        return _source;
+    }
+    
+    /* ------------------------------------------------------------ */
+    /**
+     * Do any setup necessary after starting
+     * @throws Exception
+     */
+    public void initialize()
+    throws Exception
+    {
+        if (!isStarted())
+            throw new IllegalStateException("Not started: "+this);
+    }
+
+    /* ------------------------------------------------------------ */
+    @SuppressWarnings("unchecked")
+    @Override
+    public void doStart()
+        throws Exception
+    {
+        //if no class already loaded and no classname, make permanently unavailable
+        if (_class==null && (_className==null || _className.equals("")))
+            throw new UnavailableException("No class in holder");
+        
+        //try to load class
+        if (_class==null)
+        {
+            try
+            {
+                _class=Loader.loadClass(Holder.class, _className);
+                if(LOG.isDebugEnabled())
+                    LOG.debug("Holding {} from {}",_class,_class.getClassLoader());
+            }
+            catch (Exception e)
+            {
+                LOG.warn(e);
+                throw new UnavailableException(e.getMessage());
+            }
+        }
+    }
+    
+    
+    /* ------------------------------------------------------------ */
+    @Override
+    public void doStop()
+        throws Exception
+    {
+        if (!_extInstance)
+            _class=null;
+    }
+
+
+    /* ------------------------------------------------------------ */
+    @ManagedAttribute(value="Class Name", readonly=true)
+    public String getClassName()
+    {
+        return _className;
+    }
+
+    /* ------------------------------------------------------------ */
+    public Class<? extends T> getHeldClass()
+    {
+        return _class;
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @return Returns the servletHandler.
+     */
+    public ServletHandler getServletHandler()
+    {
+        return _servletHandler;
+    }
+    
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @param servletHandler The {@link ServletHandler} that will handle requests dispatched to this servlet.
+     */
+    public void setServletHandler(ServletHandler servletHandler)
+    {
+        _servletHandler = servletHandler;
+    }
+    
+    /* ------------------------------------------------------------ */
+    /**
+     * @param className The className to set.
+     */
+    public void setClassName(String className)
+    {
+        _className = className;
+        _class=null;
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @param held The class to hold
+     */
+    public void setHeldClass(Class<? extends T> held)
+    {
+        _class=held;
+        if (held!=null)
+        {
+            _className=held.getName();
+        }
+    }
+    
+
+    /* ------------------------------------------------------------ */
+    protected void illegalStateIfContextStarted()
+    {
+        if (_servletHandler!=null)
+        {
+            ServletContext context=_servletHandler.getServletContext();
+            if ((context instanceof ContextHandler.Context) && ((ContextHandler.Context)context).getContextHandler().isStarted())
+                throw new IllegalStateException("Started");
+        }
+    }
+    
+    /* ------------------------------------------------------------ */
+    /**
+     * @return True if this holder was created for a specific instance.
+     */
+    public boolean isInstance()
+    {
+        return _extInstance;
+    }
+    
+    
+    /* ------------------------------------------------------------ */
+    @Override
+    public void dump(Appendable out, String indent) throws IOException
+    {
+        out.append(toString())
+        .append(" - ").append(AbstractLifeCycle.getState(this)).append("\n");
+    }
+
+    /* ------------------------------------------------------------ */
+    @Override
+    public String dump()
+    {
+        return ContainerLifeCycle.dump(this);
+    }
+}