Class ExprEditor
- java.lang.Object
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- javassist.expr.ExprEditor
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public class ExprEditor extends Object
A translator of method bodies.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 inCtMethod, the method body is scanned from the beginning to the end. Whenever an expression, such as a method call and anewexpression (object creation), is found,edit()is called inExprEdit.edit()can inspect and modify the given expression. The modification is reflected on the original method body. Ifedit()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
cmand it prints the names and the line numbers of the methods declared in classPoint. This code does not modify the body of the method represented bycm. If the method body must be modified, callreplace()inMethodCall.
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Constructor Summary
Constructors Constructor Description ExprEditor()Default constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description booleandoit(CtClass clazz, MethodInfo minfo)Undocumented method.voidedit(Cast c)Edits an expression for explicit type casting (overridable).voidedit(ConstructorCall c)Edits a constructor call (overridable).voidedit(FieldAccess f)Edits a field-access expression (overridable).voidedit(Handler h)Edits a catch clause (overridable).voidedit(Instanceof i)Edits an instanceof expression (overridable).voidedit(MethodCall m)Edits a method call (overridable).voidedit(NewArray a)Edits an expression for array creation (overridable).voidedit(NewExpr e)Edits anewexpression (overridable).
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Method Detail
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doit
public boolean doit(CtClass clazz, MethodInfo minfo) throws CannotCompileException
Undocumented method. Do not use; internal-use only.- Throws:
CannotCompileException
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edit
public void edit(NewExpr e) throws CannotCompileException
Edits anewexpression (overridable). The default implementation performs nothing.- Parameters:
e- thenewexpression creating an object.- Throws:
CannotCompileException
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edit
public void edit(NewArray a) throws CannotCompileException
Edits an expression for array creation (overridable). The default implementation performs nothing.- Parameters:
a- thenewexpression for creating an array.- Throws:
CannotCompileException
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edit
public void edit(MethodCall m) throws CannotCompileException
Edits a method call (overridable). The default implementation performs nothing.- Throws:
CannotCompileException
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edit
public void edit(ConstructorCall c) throws CannotCompileException
Edits a constructor call (overridable). The constructor call is eithersuper()orthis()included in a constructor body. The default implementation performs nothing.- Throws:
CannotCompileException- See Also:
edit(NewExpr)
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edit
public void edit(FieldAccess f) throws CannotCompileException
Edits a field-access expression (overridable). Field access means both read and write. The default implementation performs nothing.- Throws:
CannotCompileException
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edit
public void edit(Instanceof i) throws CannotCompileException
Edits an instanceof expression (overridable). The default implementation performs nothing.- Throws:
CannotCompileException
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edit
public void edit(Cast c) throws CannotCompileException
Edits an expression for explicit type casting (overridable). The default implementation performs nothing.- Throws:
CannotCompileException
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edit
public void edit(Handler h) throws CannotCompileException
Edits a catch clause (overridable). The default implementation performs nothing.- Throws:
CannotCompileException
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