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Tomcat example source code file (

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

Java - Tomcat tags/keywords

hashtable, hashtable, max_notes=16, object, object, runnable, string, string, thread, threadwithattributes, threadwithattributes, util

The Tomcat 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
 *  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.tomcat.util.threads;

import java.util.Hashtable;

/** Special thread that allows storing of attributes and notes.
 *  A guard is used to prevent untrusted code from accessing the
 *  attributes.
 *  This avoids hash lookups and provide something very similar
 * with ThreadLocal ( but compatible with JDK1.1 and faster on
 * JDK < 1.4 ).
 * The main use is to store 'state' for monitoring ( like "processing
 * request 'GET /' ").
public class ThreadWithAttributes extends Thread {
    private Object control;
    public static int MAX_NOTES=16;
    private Object notes[]=new Object[MAX_NOTES];
    private Hashtable attributes=new Hashtable();
    private String currentStage;
    private Object param;
    private Object thData[];

    public ThreadWithAttributes(Object control, Runnable r) {
    public final Object[] getThreadData(Object control ) {
        return thData;
    public final void setThreadData(Object control, Object thData[] ) {

    /** Notes - for attributes that need fast access ( array )
     * The application is responsible for id management
    public final void setNote( Object control, int id, Object value ) {
        if( this.control != control ) return;

    /** Information about the curent performed operation
    public final String getCurrentStage(Object control) {
        if( this.control != control ) return null;
        return currentStage;

    /** Information about the current request ( or the main object
     * we are processing )
    public final Object getParam(Object control) {
        if( this.control != control ) return null;
        return param;

    public final void setCurrentStage(Object control, String currentStage) {
        if( this.control != control ) return;
        this.currentStage = currentStage;

    public final void setParam( Object control, Object param ) {
        if( this.control != control ) return;

    public final Object getNote(Object control, int id ) {
        if( this.control != control ) return null;
        return notes[id];

    /** Generic attributes. You'll need a hashtable lookup -
     * you can use notes for array access.
    public final Hashtable getAttributes(Object control) {
        return attributes;

Other Tomcat examples (source code examples)

Here is a short list of links related to this Tomcat source code file:

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