Package org.eclipse.persistence.dynamic

Class DynamicClassWriter

  • All Implemented Interfaces:
    EclipseLinkClassWriter
    public class DynamicClassWriter
extends java.lang.Object
implements EclipseLinkClassWriter
    Write the byte codes of a dynamic entity class. The class writer will create the byte codes for a dynamic class that subclasses any provided class replicating its constructors and writeReplace method (if one exists).

    The intent is to provide a common writer for dynamic JPA entities but also allow for subclasses of this to be used in more complex writing situations such as SDO and DBWS.

    Instances of this class and any subclasses are maintained within the DynamicClassLoader.getClassWriters() and DynamicClassLoader.defaultWriter for the life of the class loader so it is important that no unnecessary state be maintained that may effect memory usage.

    Author:
    dclarke, mnorman
    Since:
    EclipseLink 1.2

    • Constructor Summary

      Constructors 
      Constructor Description
      DynamicClassWriter()  
      DynamicClassWriter​(java.lang.Class<?> parentClass)  
      DynamicClassWriter​(java.lang.String parentClassName)
      Create using a loader and class name so that the parent class can be lazily loaded when the writer is used to generate a dynamic class.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void addFields​(org.eclipse.persistence.internal.libraries.asm.ClassWriter cw, java.lang.String parentClassType)
      Allow subclasses to add additional state to the dynamic entity.
      protected void addMethods​(org.eclipse.persistence.internal.libraries.asm.ClassWriter cw, java.lang.String parentClassType)
      Allow subclasses to add additional methods to the dynamic entity.
      protected DynamicClassWriter createCopy​(java.lang.Class<?> parentClass)
      Create a copy of this DynamicClassWriter but with a different parent class.
      protected byte[] createEnum​(DynamicClassLoader.EnumInfo enumInfo)  
      protected java.lang.String[] getInterfaces()
      Interfaces the dynamic entity class implements.
      java.lang.Class<?> getParentClass()  
      java.lang.String getParentClassName()  
      boolean isCompatible​(EclipseLinkClassWriter writer)
      Verify that the provided writer is compatible with the current writer.
      java.lang.String toString()  
      protected boolean verify​(java.lang.Class<?> dynamicClass, java.lang.ClassLoader loader)
      Verify that the provided class meets the requirements of the writer.
      byte[] writeClass​(DynamicClassLoader loader, java.lang.String className)  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • DYNAMIC_PROPERTIES_MANAGER_CLASSNAME_SLASHES

        protected static final java.lang.String DYNAMIC_PROPERTIES_MANAGER_CLASSNAME_SLASHES

      • parentClass

        protected java.lang.Class<?> parentClass

      • parentClassName

        protected java.lang.String parentClassName
        Name of parent class. This is used only when the parent class is not known at the time the dynamic class writer is registered. This is generally only required when loading from an XML mapping file where the order of class access is not known.

      • ICONST

        public static int[] ICONST

    • Constructor Detail

      • DynamicClassWriter

        public DynamicClassWriter()

      • DynamicClassWriter

        public DynamicClassWriter​(java.lang.Class<?> parentClass)

      • DynamicClassWriter

        public DynamicClassWriter​(java.lang.String parentClassName)
        Create using a loader and class name so that the parent class can be lazily loaded when the writer is used to generate a dynamic class.

        The loader must not be null and the parentClassName must not be null and not an empty String. The parentClassName will be converted to a class using the provided loader lazily.

        See Also:
        getParentClass(), DynamicException.illegalDynamicClassWriter(DynamicClassLoader, String)

    • Method Detail

      • addFields

        protected void addFields​(org.eclipse.persistence.internal.libraries.asm.ClassWriter cw,
                         java.lang.String parentClassType)
        Allow subclasses to add additional state to the dynamic entity.
        Parameters:
        cw -
        parentClassType -

      • addMethods

        protected void addMethods​(org.eclipse.persistence.internal.libraries.asm.ClassWriter cw,
                          java.lang.String parentClassType)
        Allow subclasses to add additional methods to the dynamic entity.
        Parameters:
        cw -
        parentClassType -

      • verify

        protected boolean verify​(java.lang.Class<?> dynamicClass,
                         java.lang.ClassLoader loader)
                  throws java.lang.ClassNotFoundException
        Verify that the provided class meets the requirements of the writer. In the case of DynamicClassWriter this will ensure that the class is a subclass of the parentClass
        Parameters:
        dynamicClass -
        Throws:
        java.lang.ClassNotFoundException

      • getInterfaces

        protected java.lang.String[] getInterfaces()
        Interfaces the dynamic entity class implements. By default this is none but in the case of SDO a concrete interface must be implemented. Subclasses should override this as required.
        Returns:
        Interfaces implemented by Dynamic class. May be null

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object