Tomcat example source code file (DeltaRequest.java)

This example Tomcat source code file (DeltaRequest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

action_set, attributeinfo, attributeinfo, deltarequest, exception, io, ioexception, linkedlist, linkedlist, object, object, objectoutputstream, security, string, string, unable, util

The Tomcat DeltaRequest.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package org.apache.catalina.ha.session;

/**
 * This class is used to track the series of actions that happens when
 * a request is executed. These actions will then translate into invokations of methods 
 * on the actual session.
 * This class is NOT thread safe. One DeltaRequest per session
 * @author <a href="mailto:fhanik@apache.org">Filip Hanik
 * @version 1.0
 */

import java.io.Externalizable;
import java.security.Principal;
import java.util.LinkedList;

import org.apache.catalina.realm.GenericPrincipal;
import org.apache.catalina.util.StringManager;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;


public class DeltaRequest implements Externalizable {

    public static org.apache.juli.logging.Log log =
        org.apache.juli.logging.LogFactory.getLog( DeltaRequest.class );

    /**
     * The string manager for this package.
     */
    protected static StringManager sm = StringManager
            .getManager(Constants.Package);

    public static final int TYPE_ATTRIBUTE = 0;
    public static final int TYPE_PRINCIPAL = 1;
    public static final int TYPE_ISNEW = 2;
    public static final int TYPE_MAXINTERVAL = 3;

    public static final int ACTION_SET = 0;
    public static final int ACTION_REMOVE = 1;

    public static final String NAME_PRINCIPAL = "__SET__PRINCIPAL__";
    public static final String NAME_MAXINTERVAL = "__SET__MAXINTERVAL__";
    public static final String NAME_ISNEW = "__SET__ISNEW__";

    private String sessionId;
    private LinkedList actions = new LinkedList();
    private LinkedList actionPool = new LinkedList();
    
    private boolean recordAllActions = false;

    public DeltaRequest() {
        
    }
    
    public DeltaRequest(String sessionId, boolean recordAllActions) {
        this.recordAllActions=recordAllActions;
        if(sessionId != null)
            setSessionId(sessionId);
    }


    public void setAttribute(String name, Object value) {
        int action = (value==null)?ACTION_REMOVE:ACTION_SET;
        addAction(TYPE_ATTRIBUTE,action,name,value);
    }

    public void removeAttribute(String name) {
        int action = ACTION_REMOVE;
        addAction(TYPE_ATTRIBUTE,action,name,null);
    }

    public void setMaxInactiveInterval(int interval) {
        int action = ACTION_SET;
        addAction(TYPE_MAXINTERVAL,action,NAME_MAXINTERVAL,new Integer(interval));
    }
    
    /**
     * convert principal at SerializablePrincipal for backup nodes.
     * Only support principals from type {@link GenericPrincipal GenericPrincipal}
     * @param p Session principal
     * @see GenericPrincipal
     */
    public void setPrincipal(Principal p) {
        int action = (p==null)?ACTION_REMOVE:ACTION_SET;
        SerializablePrincipal sp = null;
        if ( p != null ) {
            if(p instanceof GenericPrincipal) {
                sp = SerializablePrincipal.createPrincipal((GenericPrincipal)p);
                if(log.isDebugEnabled())
                    log.debug(sm.getString("deltaRequest.showPrincipal", p.getName() , getSessionId()));
            } else
                log.error(sm.getString("deltaRequest.wrongPrincipalClass",p.getClass().getName()));
        }
        addAction(TYPE_PRINCIPAL,action,NAME_PRINCIPAL,sp);
    }

    public void setNew(boolean n) {
        int action = ACTION_SET;
        addAction(TYPE_ISNEW,action,NAME_ISNEW,new Boolean(n));
    }

    protected synchronized void addAction(int type,
                             int action,
                             String name,
                             Object value) {
        AttributeInfo info = null;
        if ( this.actionPool.size() > 0 ) {
            try {
                info = (AttributeInfo) actionPool.removeFirst();
            }catch ( Exception x ) {
                log.error("Unable to remove element:",x);
                info = new AttributeInfo(type, action, name, value);
            }
            info.init(type,action,name,value);
        } else {
            info = new AttributeInfo(type, action, name, value);
        }
        //if we have already done something to this attribute, make sure
        //we don't send multiple actions across the wire
        if ( !recordAllActions) {
            try {
                actions.remove(info);
            } catch (java.util.NoSuchElementException x) {
                //do nothing, we wanted to remove it anyway
            }
        }
        //add the action
        actions.addLast(info);
    }
    
    public void execute(DeltaSession session) {
        execute(session,true);
    }

    public synchronized void execute(DeltaSession session, boolean notifyListeners) {
        if ( !this.sessionId.equals( session.getId() ) )
            throw new java.lang.IllegalArgumentException("Session id mismatch, not executing the delta request");
        session.access();
        for ( int i=0; i<actions.size(); i++ ) {
            AttributeInfo info = (AttributeInfo)actions.get(i);
            switch ( info.getType() ) {
                case TYPE_ATTRIBUTE: {
                    if ( info.getAction() == ACTION_SET ) {
                        if ( log.isTraceEnabled() ) log.trace("Session.setAttribute('"+info.getName()+"', '"+info.getValue()+"')");
                        session.setAttribute(info.getName(), info.getValue(),notifyListeners,false);
                    }  else {
                        if ( log.isTraceEnabled() ) log.trace("Session.removeAttribute('"+info.getName()+"')");
                        session.removeAttribute(info.getName(),notifyListeners,false);
                    }
                        
                    break;
                }//case
                case TYPE_ISNEW: {
                if ( log.isTraceEnabled() ) log.trace("Session.setNew('"+info.getValue()+"')");
                    session.setNew(((Boolean)info.getValue()).booleanValue(),false);
                    break;
                }//case
                case TYPE_MAXINTERVAL: {
                    if ( log.isTraceEnabled() ) log.trace("Session.setMaxInactiveInterval('"+info.getValue()+"')");
                    session.setMaxInactiveInterval(((Integer)info.getValue()).intValue(),false);
                    break;
                }//case
                case TYPE_PRINCIPAL: {
                    Principal p = null;
                    if ( info.getAction() == ACTION_SET ) {
                        SerializablePrincipal sp = (SerializablePrincipal)info.getValue();
                        p = (Principal)sp.getPrincipal(session.getManager().getContainer().getRealm());
                    }
                    session.setPrincipal(p,false);
                    break;
                }//case
                default : throw new java.lang.IllegalArgumentException("Invalid attribute info type="+info);
            }//switch
        }//for
        session.endAccess();
        reset();
    }

    public synchronized void reset() {
        while ( actions.size() > 0 ) {
            try {
                AttributeInfo info = (AttributeInfo) actions.removeFirst();
                info.recycle();
                actionPool.addLast(info);
            }catch  ( Exception x ) {
                log.error("Unable to remove element",x);
            }
        }
        actions.clear();
    }
    
    public String getSessionId() {
        return sessionId;
    }
    public void setSessionId(String sessionId) {
        this.sessionId = sessionId;
        if ( sessionId == null ) {
            new Exception("Session Id is null for setSessionId").fillInStackTrace().printStackTrace();
        }
    }
    public int getSize() {
        return actions.size();
    }
    
    public synchronized void clear() {
        actions.clear();
        actionPool.clear();
    }
    
    public synchronized void readExternal(java.io.ObjectInput in) throws IOException,ClassNotFoundException {
        //sessionId - String
        //recordAll - boolean
        //size - int
        //AttributeInfo - in an array
        reset();
        sessionId = in.readUTF();
        recordAllActions = in.readBoolean();
        int cnt = in.readInt();
        if (actions == null)
            actions = new LinkedList();
        else
            actions.clear();
        for (int i = 0; i < cnt; i++) {
            AttributeInfo info = null;
            if (this.actionPool.size() > 0) {
                try {
                    info = (AttributeInfo) actionPool.removeFirst();
                } catch ( Exception x )  {
                    log.error("Unable to remove element",x);
                    info = new AttributeInfo(-1,-1,null,null);
                }
            }
            else {
                info = new AttributeInfo(-1,-1,null,null);
            }
            info.readExternal(in);
            actions.addLast(info);
        }//for
    }
        


    public synchronized void writeExternal(java.io.ObjectOutput out ) throws java.io.IOException {
        //sessionId - String
        //recordAll - boolean
        //size - int
        //AttributeInfo - in an array
        out.writeUTF(getSessionId());
        out.writeBoolean(recordAllActions);
        out.writeInt(getSize());
        for ( int i=0; i<getSize(); i++ ) {
            AttributeInfo info = (AttributeInfo)actions.get(i);
            info.writeExternal(out);
        }
    }
    
    /**
     * serialize DeltaRequest
     * @see DeltaRequest#writeExternal(java.io.ObjectOutput)
     * 
     * @param deltaRequest
     * @return serialized delta request
     * @throws IOException
     */
    protected byte[] serialize() throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        writeExternal(oos);
        oos.flush();
        oos.close();
        return bos.toByteArray();
    }
    
    private static class AttributeInfo implements java.io.Externalizable {
        private String name = null;
        private Object value = null;
        private int action;
        private int type;

        public AttributeInfo() {}

        public AttributeInfo(int type,
                             int action,
                             String name,
                             Object value) {
            super();
            init(type,action,name,value);
        }

        public void init(int type,
                         int action,
                         String name,
                         Object value) {
            this.name = name;
            this.value = value;
            this.action = action;
            this.type = type;
        }

        public int getType() {
            return type;
        }

        public int getAction() {
            return action;
        }

        public Object getValue() {
            return value;
        }
        public int hashCode() {
            return name.hashCode();
        }

        public String getName() {
            return name;
        }
        
        public void recycle() {
            name = null;
            value = null;
            type=-1;
            action=-1;
        }

        public boolean equals(Object o) {
            if ( ! (o instanceof AttributeInfo ) ) return false;
            AttributeInfo other =  (AttributeInfo)o;
            return other.getName().equals(this.getName());
        }
        
        public synchronized void readExternal(java.io.ObjectInput in ) throws IOException,ClassNotFoundException {
            //type - int
            //action - int
            //name - String
            //hasvalue - boolean
            //value - object
            type = in.readInt();
            action = in.readInt();
            name = in.readUTF();
            boolean hasValue = in.readBoolean();
            if ( hasValue ) value = in.readObject();
        }

        public synchronized void writeExternal(java.io.ObjectOutput out) throws IOException {
            //type - int
            //action - int
            //name - String
            //hasvalue - boolean
            //value - object
            out.writeInt(getType());
            out.writeInt(getAction());
            out.writeUTF(getName());
            out.writeBoolean(getValue()!=null);
            if (getValue()!=null) out.writeObject(getValue());
        }
        
        public String toString() {
            StringBuffer buf = new StringBuffer("AttributeInfo[type=");
            buf.append(getType()).append(", action=").append(getAction());
            buf.append(", name=").append(getName()).append(", value=").append(getValue());
            buf.append(", addr=").append(super.toString()).append("]");
            return buf.toString();
        }

    }

}