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package com.sun.management;

import java.lang.management.PlatformManagedObject;


Diagnostic management interface for the HotSpot Virtual Machine.

The diagnostic MBean is registered to the platform MBeanServer
as are other platform MBeans.

The ObjectName for uniquely identifying the diagnostic MXBean within an MBeanServer is: 
 com.sun.management:type=HotSpotDiagnostic 
 .* It can be obtained by calling the PlatformManagedObject.getObjectName method. All methods throw a NullPointerException if any input argument is null unless it's stated otherwise. 
See Also:
/**
 * Diagnostic management interface for the HotSpot Virtual Machine.
 *
 * <p>The diagnostic MBean is registered to the platform MBeanServer
 * as are other platform MBeans.
 *
 * <p>The {@code ObjectName} for uniquely identifying the diagnostic
 * MXBean within an MBeanServer is:
 * <blockquote>
 *    {@code com.sun.management:type=HotSpotDiagnostic}
 * </blockquote>
.*
 * It can be obtained by calling the
 * {@link PlatformManagedObject#getObjectName} method.
 *
 * All methods throw a {@code NullPointerException} if any input argument is
 * {@code null} unless it's stated otherwise.
 *
 * @see java.lang.management.ManagementFactory#getPlatformMXBeans(Class)
 */
public interface HotSpotDiagnosticMXBean extends PlatformManagedObject {
    
Dumps the heap to the outputFile file in the same format as the hprof heap dump. 
 If this method is called remotely from another process, the heap dump output is written to a file named outputFile on the machine where the target VM is running. If outputFile is a relative path, it is relative to the working directory where the target VM was started. 
Params:
  • outputFile – the system-dependent filename
  • live – if true dump only live objects
        i.e. objects that are reachable from others
Throws:
/**
     * Dumps the heap to the {@code outputFile} file in the same
     * format as the hprof heap dump.
     * <p>
     * If this method is called remotely from another process,
     * the heap dump output is written to a file named {@code outputFile}
     * on the machine where the target VM is running.  If outputFile is
     * a relative path, it is relative to the working directory where
     * the target VM was started.
     *
     * @param  outputFile the system-dependent filename
     * @param  live if {@code true} dump only <i>live</i> objects
     *         i.e. objects that are reachable from others
     * @throws IOException if the {@code outputFile} already exists,
     *                     cannot be created, opened, or written to.
     * @throws UnsupportedOperationException if this operation is not supported.
     * @throws IllegalArgumentException if {@code outputFile} does not end with ".hprof" suffix.
     * @throws NullPointerException if {@code outputFile} is {@code null}.
     * @throws SecurityException
     *         If a security manager exists and its {@link
     *         java.lang.SecurityManager#checkWrite(java.lang.String)}
     *         method denies write access to the named file
     *         or the caller does not have ManagmentPermission("control").
     */
    public void dumpHeap(String outputFile, boolean live) throws java.io.IOException;

    
Returns a list of VMOption objects for all diagnostic options. A diagnostic option is a writeable VM option that can be set dynamically mainly for troubleshooting and diagnosis. 
Returns:a list of VMOption objects for all diagnostic options.
/**
     * Returns a list of {@code VMOption} objects for all diagnostic options.
     * A diagnostic option is a {@link VMOption#isWriteable writeable}
     * VM option that can be set dynamically mainly for troubleshooting
     * and diagnosis.
     *
     * @return a list of {@code VMOption} objects for all diagnostic options.
     */
    public java.util.List<VMOption> getDiagnosticOptions();

    
Returns a VMOption object for a VM option of the given name. 
Throws:
Returns:a VMOption object for a VM option of the given name.
/**
     * Returns a {@code VMOption} object for a VM option of the given
     * name.
     *
     * @return a {@code VMOption} object for a VM option of the given name.
     * @throws NullPointerException if name is {@code null}.
     * @throws IllegalArgumentException if a VM option of the given name
     *                                     does not exist.
     */
    public VMOption getVMOption(String name);

    
Sets a VM option of the given name to the specified value. The new value will be reflected in a new VMOption object returned by the getVMOption method or the getDiagnosticOptions method. This method does not change the value of this VMOption object. 
Params:
  • name – Name of a VM option
  • value – New value of the VM option to be set
Throws:
/**
     * Sets a VM option of the given name to the specified value.
     * The new value will be reflected in a new {@code VMOption}
     * object returned by the {@link #getVMOption} method or
     * the {@link #getDiagnosticOptions} method.  This method does
     * not change the value of this {@code VMOption} object.
     *
     * @param name Name of a VM option
     * @param value New value of the VM option to be set
     *
     * @throws IllegalArgumentException if the VM option of the given name
     *                                     does not exist.
     * @throws IllegalArgumentException if the new value is invalid.
     * @throws IllegalArgumentException if the VM option is not writable.
     * @throws NullPointerException if name or value is {@code null}.
     *
     * @throws  java.lang.SecurityException
     *     if a security manager exists and the caller does not have
     *     ManagementPermission("control").
     */
    public void setVMOption(String name, String value);
}