org.eclipse.persistence.internal.jpa.weaving

Class MethodWeaver

java.lang.Object

MethodVisitor

org.eclipse.persistence.internal.jpa.weaving.MethodWeaver

public class MethodWeaver
extends MethodVisitor

Processes all the methods of a class to weave in persistence code such as, lazy value holder, change tracking and fetch groups. For FIELD access, changes references to GETFIELD and PUTFIELD to call weaved get/set methods. For Property access, modifies the getters and setters.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	methodDescriptor
protected java.lang.String	methodName
protected boolean	methodStarted Determines if we are at the first line of a method.
protected ClassWeaver	tcw

Constructor Summary

Constructors

Constructor and Description
MethodWeaver(ClassWeaver tcw, java.lang.String methodName, java.lang.String methodDescriptor, MethodVisitor mv)

Method Summary

Modifier and Type	Method and Description
void	visitAttribute(Attribute attr)
void	visitFieldInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc)
void	visitIincInsn(int var, int increment)
void	visitInsn(int opcode)
void	visitIntInsn(int opcode, int operand)
void	visitJumpInsn(int opcode, Label label)
void	visitLabel(Label label)
void	visitLdcInsn(java.lang.Object cst)
void	visitLineNumber(int line, Label start)
void	visitLocalVariable(java.lang.String name, java.lang.String desc, java.lang.String signature, Label start, Label end, int index)
void	visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels)
void	visitMaxs(int maxStack, int maxLocals)
void	visitMethodInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc, boolean intf)
void	visitMultiANewArrayInsn(java.lang.String desc, int dims)
void	visitTableSwitchInsn(int min, int max, Label dflt, Label... labels)
void	visitTryCatchBlock(Label start, Label end, Label handler, java.lang.String type)
void	visitTypeInsn(int opcode, java.lang.String desc)
void	visitVarInsn(int opcode, int var)
void	weaveAttributesIfRequired(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc) Change GETFIELD and PUTFIELD for fields that use attribute access to make use of new convenience methods.
void	weaveBeginningOfMethodIfRequired() Makes modifications to the beginning of a method.
void	weaveEndOfMethodIfRequired() Modifies methods just before the return.

Methods inherited from class java.lang.Object

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

Field Detail

tcw

protected ClassWeaver tcw

methodName

protected java.lang.String methodName

methodDescriptor

protected java.lang.String methodDescriptor

methodStarted

protected boolean methodStarted

Determines if we are at the first line of a method.

Constructor Detail

MethodWeaver

public MethodWeaver(ClassWeaver tcw,
                    java.lang.String methodName,
                    java.lang.String methodDescriptor,
                    MethodVisitor mv)

Method Detail

visitInsn

public void visitInsn(int opcode)

visitIntInsn

public void visitIntInsn(int opcode,
                         int operand)

visitVarInsn

public void visitVarInsn(int opcode,
                         int var)

visitTypeInsn

public void visitTypeInsn(int opcode,
                          java.lang.String desc)

visitFieldInsn

public void visitFieldInsn(int opcode,
                           java.lang.String owner,
                           java.lang.String name,
                           java.lang.String desc)

visitMethodInsn

public void visitMethodInsn(int opcode,
                            java.lang.String owner,
                            java.lang.String name,
                            java.lang.String desc,
                            boolean intf)

visitJumpInsn

public void visitJumpInsn(int opcode,
                          Label label)

visitLabel

public void visitLabel(Label label)

visitLdcInsn

public void visitLdcInsn(java.lang.Object cst)

visitIincInsn

public void visitIincInsn(int var,
                          int increment)

visitTableSwitchInsn

public void visitTableSwitchInsn(int min,
                                 int max,
                                 Label dflt,
                                 Label... labels)

visitLookupSwitchInsn

public void visitLookupSwitchInsn(Label dflt,
                                  int[] keys,
                                  Label[] labels)

visitMultiANewArrayInsn

public void visitMultiANewArrayInsn(java.lang.String desc,
                                    int dims)

visitTryCatchBlock

public void visitTryCatchBlock(Label start,
                               Label end,
                               Label handler,
                               java.lang.String type)

visitMaxs

public void visitMaxs(int maxStack,
                      int maxLocals)

visitLocalVariable

public void visitLocalVariable(java.lang.String name,
                               java.lang.String desc,
                               java.lang.String signature,
                               Label start,
                               Label end,
                               int index)

visitLineNumber

public void visitLineNumber(int line,
                            Label start)

visitAttribute

public void visitAttribute(Attribute attr)

weaveAttributesIfRequired

public void weaveAttributesIfRequired(int opcode,
                                      java.lang.String owner,
                                      java.lang.String name,
                                      java.lang.String desc)

Change GETFIELD and PUTFIELD for fields that use attribute access to make use of new convenience methods. A GETFIELD for an attribute named 'variableName' will be replaced by a call to: _persistence_get_variableName() A PUTFIELD for an attribute named 'variableName' will be replaced by a call to: _persistence_set_variableName(variableName)

weaveBeginningOfMethodIfRequired

public void weaveBeginningOfMethodIfRequired()

Makes modifications to the beginning of a method. 1. Modifies getter method for attributes using property access In a getter method for 'attributeName', the following lines are added at the beginning of the method _persistence_checkFetched("attributeName"); _persistence_initialize_attributeName_vh(); if (!_persistence_attributeName_vh.isInstantiated()) { PropertyChangeListener temp_persistence_listener = _persistence_listener; _persistence_listener = null; setAttributeName((AttributeType)_persistence_attributeName_vh.getValue()); _persistence_listener = temp_persistence_listener; } 2. Modifies setter methods to store old value of attribute If weaving for fetch groups: // if weaving for change tracking: if(_persistence_listener != null) // for Objects AttributeType oldAttribute = getAttribute() // for primitives AttributeWrapperType oldAttribute = new AttributeWrapperType(getAttribute()); e.g. Double oldAttribute = new Double(getAttribute()); else _persistence_checkFetchedForSet("attributeName"); _persistence_propertyChange("attributeName", oldAttribute, argument); otherwise (not weaving for fetch groups): // for Objects AttributeType oldAttribute = getAttribute() // for primitives AttributeWrapperType oldAttribute = new AttributeWrapperType(getAttribute()); e.g. Double oldAttribute = new Double(getAttribute()); _persistence_propertyChange("attributeName", oldAttribute, argument); // if not weaving for change tracking, but for fetch groups only: _persistence_checkFetchedForSet("attributeName"); 3. Modifies getter Method for attributes using virtual access add: _persistence_checkFetched(name); 4. Modifies setter Method for attributes using virtual access add code of the following form: Object obj = null; if(_persistence_listener != null){ obj = get(name); } else { _persistence_checkFetchedForSet(name); } _persistence_propertyChange(name, obj, value); _persistence_checkFetchedForSet(name) call will be excluded if weaving of fetch groups is not enabled _persistence_propertyChange(name, obj, value); will be excluded if weaving of change tracking is not enabled

weaveEndOfMethodIfRequired

public void weaveEndOfMethodIfRequired()

Modifies methods just before the return. In a setter method for a LAZY mapping, for 'attributeName', the following lines are added at the end of the method. _persistence_initialize_attributeName_vh(); _persistence_attributeName_vh.setValue(argument); _persistence_attributeName_vh.setIsCoordinatedWithProperty(true); In a setter method for a non-LAZY mapping, the followings lines are added if change tracking is activated: _persistence_propertyChange("attributeName", oldAttribute, argument); Note: This code will wrap primitives by adding a call to the primitive constructor.