Module jdk.management
Package com.sun.management

Class GcInfo

  • All Implemented Interfaces:
    CompositeData, CompositeDataView
    public class GcInfo
extends Object
implements CompositeData, CompositeDataView
    Garbage collection information. It contains the following information for one garbage collection as well as GC-specific attributes:
    • Start time
    • End time
    • Duration
    • Memory usage before the collection starts
    • Memory usage after the collection ends

    GcInfo is a CompositeData The GC-specific attributes can be obtained via the CompositeData interface. This is a historical relic, and other classes should not copy this pattern. Use CompositeDataView instead.

    MXBean Mapping

    GcInfo is mapped to a CompositeData with attributes as specified in the from method.
    Since:
    1.5

    • Method Detail

      • getId

        public long getId()
        Returns the identifier of this garbage collection which is the number of collections that this collector has done.
        Returns:
        the identifier of this garbage collection which is the number of collections that this collector has done.

      • getStartTime

        public long getStartTime()
        Returns the start time of this GC in milliseconds since the Java virtual machine was started.
        Returns:
        the start time of this GC.

      • getEndTime

        public long getEndTime()
        Returns the end time of this GC in milliseconds since the Java virtual machine was started.
        Returns:
        the end time of this GC.

      • getDuration

        public long getDuration()
        Returns the elapsed time of this GC in milliseconds.
        Returns:
        the elapsed time of this GC in milliseconds.

      • getMemoryUsageBeforeGc

        public Map<String,MemoryUsage> getMemoryUsageBeforeGc()
        Returns the memory usage of all memory pools at the beginning of this GC. This method returns a Map of the name of a memory pool to the memory usage of the corresponding memory pool before GC starts.
        Returns:
        a Map of memory pool names to the memory usage of a memory pool before GC starts.

      • getMemoryUsageAfterGc

        public Map<String,MemoryUsage> getMemoryUsageAfterGc()
        Returns the memory usage of all memory pools at the end of this GC. This method returns a Map of the name of a memory pool to the memory usage of the corresponding memory pool when GC finishes.
        Returns:
        a Map of memory pool names to the memory usage of a memory pool when GC finishes.

      • from

        public static GcInfo from​(CompositeData cd)
        Returns a GcInfo object represented by the given CompositeData. The given CompositeData must contain all the following attributes:
        description
        Attribute Name Type
        index java.lang.Long
        startTime java.lang.Long
        endTime java.lang.Long
        memoryUsageBeforeGc javax.management.openmbean.TabularData
        memoryUsageAfterGc javax.management.openmbean.TabularData
        Returns:
        a GcInfo object represented by cd if cd is not null; null otherwise.
        Throws:
        IllegalArgumentException - if cd does not represent a GcInfo object with the attributes described above.

      • toCompositeData

        public CompositeData toCompositeData​(CompositeType ct)
        Return the CompositeData representation of this GcInfo, including any GC-specific attributes. The returned value will have at least all the attributes described in the from method, plus optionally other attributes.
        Specified by:
        toCompositeData in interface CompositeDataView
        Parameters:
        ct - the CompositeType that the caller expects. This parameter is ignored and can be null.
        Returns:
        the CompositeData representation.