Package org.hibernate

Enum LockMode

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<LockMode>
    public enum LockMode
extends java.lang.Enum<LockMode>
    Instances represent a lock mode for a row of a relational database table. It is not intended that users spend much time worrying about locking since Hibernate usually obtains exactly the right lock level automatically. Some "advanced" users may wish to explicitly specify lock levels.
    See Also:
    Session.lock(Object, LockMode)

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description
      FORCE
      Deprecated.
      instead use PESSIMISTIC_FORCE_INCREMENT
      NONE
      No lock required.
      OPTIMISTIC
      Optimistically assume that transaction will not experience contention for entities.
      OPTIMISTIC_FORCE_INCREMENT
      Optimistically assume that transaction will not experience contention for entities.
      PESSIMISTIC_FORCE_INCREMENT
      Transaction will immediately increment the entity version.
      PESSIMISTIC_READ
      Implemented as PESSIMISTIC_WRITE.
      PESSIMISTIC_WRITE
      Transaction will obtain a database lock immediately.
      READ
      A shared lock.
      UPGRADE
      Deprecated.
      instead use PESSIMISTIC_WRITE
      UPGRADE_NOWAIT
      Attempt to obtain an upgrade lock, using an Oracle-style select for update nowait.
      UPGRADE_SKIPLOCKED
      Attempt to obtain an upgrade lock, using an Oracle-style select for update skip locked.
      WRITE
      A WRITE lock is obtained when an object is updated or inserted.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static LockMode fromExternalForm​(java.lang.String externalForm)  
      boolean greaterThan​(LockMode mode)
      Check if this lock mode is more restrictive than the given lock mode.
      boolean lessThan​(LockMode mode)
      Check if this lock mode is less restrictive than the given lock mode.
      java.lang.String toExternalForm()  
      static LockMode valueOf​(java.lang.String name)
      Returns the enum constant of this type with the specified name.
      static LockMode[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.

      • Methods inherited from class java.lang.Enum

        clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

    • Enum Constant Detail

      • NONE

        public static final LockMode NONE
        No lock required. If an object is requested with this lock mode, a READ lock will be obtained if it is necessary to actually read the state from the database, rather than pull it from a cache.

        This is the "default" lock mode.

      • READ

        public static final LockMode READ
        A shared lock. Objects in this lock mode were read from the database in the current transaction, rather than being pulled from a cache.

      • UPGRADE

        @Deprecated
public static final LockMode UPGRADE
        Deprecated.
        instead use PESSIMISTIC_WRITE
        An upgrade lock. Objects loaded in this lock mode are materialized using an SQL select ... for update.

      • UPGRADE_NOWAIT

        public static final LockMode UPGRADE_NOWAIT
        Attempt to obtain an upgrade lock, using an Oracle-style select for update nowait. The semantics of this lock mode, once obtained, are the same as UPGRADE.

      • UPGRADE_SKIPLOCKED

        public static final LockMode UPGRADE_SKIPLOCKED
        Attempt to obtain an upgrade lock, using an Oracle-style select for update skip locked. The semantics of this lock mode, once obtained, are the same as UPGRADE.

      • WRITE

        public static final LockMode WRITE
        A WRITE lock is obtained when an object is updated or inserted. This lock mode is for internal use only and is not a valid mode for load() or lock() (both of which throw exceptions if WRITE is specified).

      • FORCE

        @Deprecated
public static final LockMode FORCE
        Deprecated.
        instead use PESSIMISTIC_FORCE_INCREMENT
        Similar to UPGRADE except that, for versioned entities, it results in a forced version increment.

      • OPTIMISTIC

        public static final LockMode OPTIMISTIC
        Optimistically assume that transaction will not experience contention for entities. The entity version will be verified near the transaction end.

      • OPTIMISTIC_FORCE_INCREMENT

        public static final LockMode OPTIMISTIC_FORCE_INCREMENT
        Optimistically assume that transaction will not experience contention for entities. The entity version will be verified and incremented near the transaction end.

      • PESSIMISTIC_READ

        public static final LockMode PESSIMISTIC_READ
        Implemented as PESSIMISTIC_WRITE. TODO: introduce separate support for PESSIMISTIC_READ

      • PESSIMISTIC_WRITE

        public static final LockMode PESSIMISTIC_WRITE
        Transaction will obtain a database lock immediately. TODO: add PESSIMISTIC_WRITE_NOWAIT

      • PESSIMISTIC_FORCE_INCREMENT

        public static final LockMode PESSIMISTIC_FORCE_INCREMENT
        Transaction will immediately increment the entity version.

    • Method Detail

      • values

        public static LockMode[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (LockMode c : LockMode.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static LockMode valueOf​(java.lang.String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
        java.lang.NullPointerException - if the argument is null

      • greaterThan

        public boolean greaterThan​(LockMode mode)
        Check if this lock mode is more restrictive than the given lock mode.
        Parameters:
        mode - LockMode to check
        Returns:
        true if this lock mode is more restrictive than given lock mode

      • lessThan

        public boolean lessThan​(LockMode mode)
        Check if this lock mode is less restrictive than the given lock mode.
        Parameters:
        mode - LockMode to check
        Returns:
        true if this lock mode is less restrictive than given lock mode

      • toExternalForm

        public java.lang.String toExternalForm()

      • fromExternalForm

        public static LockMode fromExternalForm​(java.lang.String externalForm)