/*
 * @(#)ClassLoadingMXBean.java	1.11 04/04/20
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.lang.management;

/**
 * The management interface for the class loading system of 
 * the Java virtual machine. 
 *
 * <p> A Java virtual machine has a single instance of the implementation
 * class of this interface.  This instance implementing this interface is 
 * an <a href="ManagementFactory.html#MXBean">MXBean</a>
 * that can be obtained by calling
 * the {@link ManagementFactory#getClassLoadingMXBean} method or
 * from the {@link ManagementFactory#getPlatformMBeanServer
 * platform <tt>MBeanServer</tt>} method.
 *
 * <p>The <tt>ObjectName</tt> for uniquely identifying the MXBean for 
 * the class loading system within an <tt>MBeanServer</tt> is:
 * <blockquote>
 * {@link ManagementFactory#CLASS_LOADING_MXBEAN_NAME 
 *        <tt>java.lang:type=ClassLoading</tt>}
 * </blockquote>
 *
 * @see <a href="../../../javax/management/package-summary.html">
 *      JMX Specification.</a>
 * @see <a href="package-summary.html#examples">
 *      Ways to Access MXBeans</a>
 *
 * @author  Mandy Chung
 * @version 1.11, 04/20/04
 * @since   1.5 
 */
public interface ClassLoadingMXBean {
    
    /** 
     * Returns the total number of classes that have been loaded since
     * the Java virtual machine has started execution.
     *
     * @return the total number of classes loaded.
     *
     */
    public long getTotalLoadedClassCount();
    
    /** 
     * Returns the number of classes that are currently loaded in the 
     * Java virtual machine.
     *
     * @return the number of currently loaded classes.
     */
    public int getLoadedClassCount();
    
    /** 
     * Returns the total number of classes unloaded since the Java virtual machine
     * has started execution.
     *
     * @return the total number of unloaded classes.
     */
    public long getUnloadedClassCount();

    /**
     * Tests if the verbose output for the class loading system is enabled.
     *
     * @return <tt>true</tt> if the verbose output for the class loading
     * system is enabled; <tt>false</tt> otherwise.
     */
    public boolean isVerbose();

    /**
     * Enables or disables the verbose output for the class loading 
     * system.  The verbose output information and the output stream
     * to which the verbose information is emitted are implementation
     * dependent.  Typically, a Java virtual machine implementation 
     * prints a message each time a class file is loaded. 
     *
     * <p>This method can be called by multiple threads concurrently.
     * Each invocation of this method enables or disables the verbose
     * output globally.
     *
     * @param value <tt>true</tt> to enable the verbose output;
     *              <tt>false</tt> to disable.
     *
     * @exception  java.lang.SecurityException if a security manager 
     *             exists and the caller does not have 
     *             ManagementPermission("control").
     */
    public void setVerbose(boolean value);

}