public class ExprEditor
extends java.lang.Object
The users can define a subclass of this class to customize how to modify a method body. The overall architecture is similar to the strategy pattern.
If instrument()
is called in
CtMethod
, the method body is scanned from the beginning
to the end.
Whenever an expression, such as a method call and a new
expression (object creation),
is found, edit()
is called in ExprEdit
.
edit()
can inspect and modify the given expression.
The modification is reflected on the original method body. If
edit()
does nothing, the original method body is not
changed.
The following code is an example:
CtMethod cm = ...; cm.instrument(new ExprEditor() { public void edit(MethodCall m) throws CannotCompileException { if (m.getClassName().equals("Point")) { System.out.println(m.getMethodName() + " line: " + m.getLineNumber()); } });
This code inspects all method calls appearing in the method represented
by cm
and it prints the names and the line numbers of the
methods declared in class Point
. This code does not modify
the body of the method represented by cm
. If the method
body must be modified, call replace()
in MethodCall
.
Modifier and Type | Class and Description |
---|---|
(package private) static class |
ExprEditor.LoopContext |
(package private) static class |
ExprEditor.NewOp |
Constructor and Description |
---|
ExprEditor()
Default constructor.
|
Modifier and Type | Method and Description |
---|---|
boolean |
doit(CtClass clazz,
MethodInfo minfo)
Undocumented method.
|
(package private) boolean |
doit(CtClass clazz,
MethodInfo minfo,
ExprEditor.LoopContext context,
CodeIterator iterator,
int endPos)
Visits each bytecode in the given range.
|
void |
edit(Cast c)
Edits an expression for explicit type casting (overridable).
|
void |
edit(ConstructorCall c)
Edits a constructor call (overridable).
|
void |
edit(FieldAccess f)
Edits a field-access expression (overridable).
|
void |
edit(Handler h)
Edits a catch clause (overridable).
|
void |
edit(Instanceof i)
Edits an instanceof expression (overridable).
|
void |
edit(MethodCall m)
Edits a method call (overridable).
|
void |
edit(NewArray a)
Edits an expression for array creation (overridable).
|
void |
edit(NewExpr e)
Edits a new expression (overridable).
|
(package private) boolean |
loopBody(CodeIterator iterator,
CtClass clazz,
MethodInfo minfo,
ExprEditor.LoopContext context) |
public boolean doit(CtClass clazz, MethodInfo minfo) throws CannotCompileException
CannotCompileException
boolean doit(CtClass clazz, MethodInfo minfo, ExprEditor.LoopContext context, CodeIterator iterator, int endPos) throws CannotCompileException
CannotCompileException
final boolean loopBody(CodeIterator iterator, CtClass clazz, MethodInfo minfo, ExprEditor.LoopContext context) throws CannotCompileException
CannotCompileException
public void edit(NewExpr e) throws CannotCompileException
e
- the new expression creating an object.CannotCompileException
public void edit(NewArray a) throws CannotCompileException
a
- the new expression for creating an array.CannotCompileException
public void edit(MethodCall m) throws CannotCompileException
CannotCompileException
public void edit(ConstructorCall c) throws CannotCompileException
super()
or this()
included in a constructor body.
The default implementation performs nothing.CannotCompileException
edit(NewExpr)
public void edit(FieldAccess f) throws CannotCompileException
CannotCompileException
public void edit(Instanceof i) throws CannotCompileException
CannotCompileException
public void edit(Cast c) throws CannotCompileException
CannotCompileException
public void edit(Handler h) throws CannotCompileException
CannotCompileException