LockInfo (Java SE 12 & JDK 12 )
Keywords: java.lang.management.LockInfo class

Module java.management
Package java.lang.management

## Class LockInfo

- java.lang.Object
- - java.lang.management.LockInfo

- Direct Known Subclasses:
    `MonitorInfo`

      public class LockInfo
      extends Object

  Information about a lock. A lock can be a built-in object monitor, an ownable synchronizer, or the `Condition` object associated with synchronizers.

  An ownable synchronizer is a synchronizer that may be exclusively owned by a thread and uses `AbstractOwnableSynchronizer` (or its subclass) to implement its synchronization property. `ReentrantLock` and the write-lock (but not the read-lock) of `ReentrantReadWriteLock` are two examples of ownable synchronizers provided by the platform.

  ### MXBean Mapping

  `LockInfo` is mapped to a `CompositeData` as specified in the `from` method.
  Since:
    1.6
  See Also:
    `AbstractOwnableSynchronizer`, `Condition`

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `LockInfo​(String className, int identityHashCode)` | Constructs a `LockInfo` object.

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `static LockInfo` | `from​(CompositeData cd)` | Returns a `LockInfo` object represented by the given `CompositeData`.
    `String` | `getClassName()` | Returns the fully qualified name of the class of the lock object.
    `int` | `getIdentityHashCode()` | Returns the identity hash code of the lock object returned from the `System.identityHashCode(java.lang.Object)` method.
    `String` | `toString()` | Returns a string representation of a lock.

    - ### Methods declared in class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### LockInfo

          public LockInfo​(String className,
                          int identityHashCode)

      Constructs a `LockInfo` object.
      Parameters:
        `className` - the fully qualified name of the class of the lock object.
        `identityHashCode` - the `identity hash code` of the lock object.

  - ### Method Detail

    - #### getClassName

          public String getClassName()

      Returns the fully qualified name of the class of the lock object.
      Returns:
        the fully qualified name of the class of the lock object.

    - #### getIdentityHashCode

          public int getIdentityHashCode()

      Returns the identity hash code of the lock object returned from the `System.identityHashCode(java.lang.Object)` method.
      Returns:
        the identity hash code of the lock object.

    - #### from

          public static LockInfo from​(CompositeData cd)

      Returns a `LockInfo` object represented by the given `CompositeData`. The given `CompositeData` must contain the following attributes:

      The attributes and the types the given CompositeData contains
      Attribute Name | Type
      --- | ---
      className | `java.lang.String`
      identityHashCode | `java.lang.Integer`

      Parameters:
        `cd` - `CompositeData` representing a `LockInfo`
      Returns:
        a `LockInfo` object represented by `cd` if `cd` is not `null`; `null` otherwise.
      Throws:
        `IllegalArgumentException` - if `cd` does not represent a `LockInfo` with the attributes described above.
      Since:
        1.8

    - #### toString

          public String toString()

      Returns a string representation of a lock. The returned string representation consists of the name of the class of the lock object, the at-sign character `@', and the unsigned hexadecimal representation of the identity hash code of the object. This method returns a string equals to the value of:

      >      lock.getClass().getName() + '@' + Integer.toHexString(System.identityHashCode(lock))

      where `lock` is the lock object.
      Overrides:
        `toString` in class `Object`
      Returns:
        the string representation of a lock.