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Commons DBCP example source code file (AbandonedTrace.java)

This example Commons DBCP source code file (AbandonedTrace.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 - Commons DBCP tags/keywords

abandonedconfig, abandonedconfig, abandonedobjectexception, abandonedobjectexception, abandonedtrace, abandonedtrace, arraylist, date, exception, hh:mm:ss, list, simpledateformat, string, string, text, util

The Commons DBCP AbandonedTrace.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.commons.dbcp;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

/**
 * Tracks db connection usage for recovering and reporting
 * abandoned db connections.
 *
 * The JDBC Connection, Statement, and ResultSet classes
 * extend this class.
 * 
 * @author Glenn L. Nielsen
 * @version $Revision: 899987 $ $Date: 2010-01-16 11:51:16 -0500 (Sat, 16 Jan 2010) $
 */
public class AbandonedTrace {

    /** DBCP AbandonedConfig */
    private final AbandonedConfig config;
    /** A stack trace of the code that created me (if in debug mode) */
    private volatile Exception createdBy;
    /** A list of objects created by children of this object */
    private final List traceList = new ArrayList();
    /** Last time this connection was used */
    private volatile long lastUsed = 0;

    /**
     * Create a new AbandonedTrace without config and
     * without doing abandoned tracing.
     */
    public AbandonedTrace() {
        this.config = null;
        init(null);
    }

    /**
     * Construct a new AbandonedTrace with no parent object.
     *
     * @param config AbandonedConfig
     */
    public AbandonedTrace(AbandonedConfig config) {
        this.config = config;
        init(null);
    }

    /**
     * Construct a new AbandonedTrace with a parent object.
     *
     * @param parent AbandonedTrace parent object
     */
    public AbandonedTrace(AbandonedTrace parent) {
        this.config = parent.getConfig();
        init(parent);
    }

    /**
     * Initialize abandoned tracing for this object.
     *
     * @param parent AbandonedTrace parent object
     */
    private void init(AbandonedTrace parent) {
        if (parent != null) {                  
            parent.addTrace(this);
        }

        if (config == null) {
            return;
        }
        if (config.getLogAbandoned()) {
            createdBy = new AbandonedObjectException();
        }
    }

    /**
     * Get the abandoned config for this object.
     *
     * @return AbandonedConfig for this object
     */
    protected AbandonedConfig getConfig() {
        return config;
    }

    /**
     * Get the last time this object was used in ms.
     *
     * @return long time in ms
     */
    protected long getLastUsed() {
        return lastUsed;
    }

    /**
     * Set the time this object was last used to the
     * current time in ms.
     */
    protected void setLastUsed() {
        lastUsed = System.currentTimeMillis();
    }

    /**
     * Set the time in ms this object was last used.
     *
     * @param time time in ms
     */
    protected void setLastUsed(long time) {
        lastUsed = time;
    }

    /**
     * If logAbandoned=true generate a stack trace
     * for this object then add this object to the parent
     * object trace list.
     */
    protected void setStackTrace() {
        if (config == null) {                 
            return;                           
        }                    
        if (config.getLogAbandoned()) {
            createdBy = new AbandonedObjectException();
        }
    }

    /**
     * Add an object to the list of objects being
     * traced.
     *
     * @param trace AbandonedTrace object to add
     */
    protected void addTrace(AbandonedTrace trace) {
        synchronized (this.traceList) {
            this.traceList.add(trace);
        }
        setLastUsed();
    }

    /**
     * Clear the list of objects being traced by this
     * object.
     */
    protected void clearTrace() {
        synchronized(this.traceList) {
            this.traceList.clear();
        }
    }

    /**
     * Get a list of objects being traced by this object.
     *
     * @return List of objects
     */
    protected List getTrace() {
        synchronized (this.traceList) {
            return new ArrayList(traceList);
        }
    }

    /**
     * Prints a stack trace of the code that
     * created this object.
     */
    public void printStackTrace() {
        if (createdBy != null && config != null) {
            createdBy.printStackTrace(config.getLogWriter());
        }
        synchronized(this.traceList) {
            Iterator it = this.traceList.iterator();
            while (it.hasNext()) {
                AbandonedTrace at = (AbandonedTrace)it.next();
                at.printStackTrace();
            }
        }
    }

    /**
     * Remove a child object this object is tracing.
     *
     * @param trace AbandonedTrace object to remove
     */
    protected void removeTrace(AbandonedTrace trace) {
        synchronized(this.traceList) {
            this.traceList.remove(trace);
        }
    }

    static class AbandonedObjectException extends Exception {

        private static final long serialVersionUID = 7398692158058772916L;

        /** Date format */
        //@GuardedBy("this")
        private static final SimpleDateFormat format = new SimpleDateFormat
            ("'DBCP object created' yyyy-MM-dd HH:mm:ss " +
             "'by the following code was never closed:'");

        private final long _createdTime;

        public AbandonedObjectException() {
            _createdTime = System.currentTimeMillis();
        }

        // Override getMessage to avoid creating objects and formatting
        // dates unless the log message will actually be used.
        public String getMessage() {
            String msg;
            synchronized(format) {
                msg = format.format(new Date(_createdTime));
            }
            return msg;
        }
    }
}

Other Commons DBCP examples (source code examples)

Here is a short list of links related to this Commons DBCP AbandonedTrace.java source code file:

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