Package org.objectweb.asm.util
Class TraceClassVisitor
- java.lang.Object
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- org.objectweb.asm.ClassVisitor
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- org.objectweb.asm.util.TraceClassVisitor
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public final class TraceClassVisitor extends ClassVisitor
AClassVisitor
that prints the classes it visits with aPrinter
. This class visitor can be used in the middle of a class visitor chain to trace the class that is visited at a given point in this chain. This may be useful for debugging purposes.When used with a
Textifier
, the trace printed when visiting theHello
class is the following:// class version 49.0 (49) // access flags 0x21 public class Hello { // compiled from: Hello.java // access flags 0x1 public <init> ()V ALOAD 0 INVOKESPECIAL java/lang/Object <init> ()V RETURN MAXSTACK = 1 MAXLOCALS = 1 // access flags 0x9 public static main ([Ljava/lang/String;)V GETSTATIC java/lang/System out Ljava/io/PrintStream; LDC "hello" INVOKEVIRTUAL java/io/PrintStream println (Ljava/lang/String;)V RETURN MAXSTACK = 2 MAXLOCALS = 1 }
where
Hello
is defined by:public class Hello { public static void main(String[] args) { System.out.println("hello"); } }
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Field Summary
Fields Modifier and Type Field Description Printer
p
The printer to convert the visited class into text.-
Fields inherited from class org.objectweb.asm.ClassVisitor
api, cv
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Constructor Summary
Constructors Constructor Description TraceClassVisitor(PrintWriter printWriter)
Constructs a newTraceClassVisitor
.TraceClassVisitor(ClassVisitor classVisitor, PrintWriter printWriter)
Constructs a newTraceClassVisitor
.TraceClassVisitor(ClassVisitor classVisitor, Printer printer, PrintWriter printWriter)
Constructs a newTraceClassVisitor
.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
visit(int version, int access, String name, String signature, String superName, String[] interfaces)
Visits the header of the class.AnnotationVisitor
visitAnnotation(String descriptor, boolean visible)
Visits an annotation of the class.void
visitAttribute(Attribute attribute)
Visits a non standard attribute of the class.void
visitEnd()
Visits the end of the class.FieldVisitor
visitField(int access, String name, String descriptor, String signature, Object value)
Visits a field of the class.void
visitInnerClass(String name, String outerName, String innerName, int access)
Visits information about an inner class.MethodVisitor
visitMethod(int access, String name, String descriptor, String signature, String[] exceptions)
Visits a method of the class.ModuleVisitor
visitModule(String name, int flags, String version)
Visit the module corresponding to the class.void
visitNestHost(String nestHost)
Visits the nest host class of the class.void
visitNestMember(String nestMember)
Visits a member of the nest.void
visitOuterClass(String owner, String name, String descriptor)
Visits the enclosing class of the class.void
visitSource(String file, String debug)
Visits the source of the class.AnnotationVisitor
visitTypeAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible)
Visits an annotation on a type in the class signature.
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Field Detail
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p
public final Printer p
The printer to convert the visited class into text.
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Constructor Detail
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TraceClassVisitor
public TraceClassVisitor(PrintWriter printWriter)
Constructs a newTraceClassVisitor
.- Parameters:
printWriter
- the print writer to be used to print the class. May be null.
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TraceClassVisitor
public TraceClassVisitor(ClassVisitor classVisitor, PrintWriter printWriter)
Constructs a newTraceClassVisitor
.- Parameters:
classVisitor
- the class visitor to which to delegate calls. May be null.printWriter
- the print writer to be used to print the class. May be null.
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TraceClassVisitor
public TraceClassVisitor(ClassVisitor classVisitor, Printer printer, PrintWriter printWriter)
Constructs a newTraceClassVisitor
.- Parameters:
classVisitor
- the class visitor to which to delegate calls. May be null.printer
- the printer to convert the visited class into text.printWriter
- the print writer to be used to print the class. May be null.
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Method Detail
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visit
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces)
Description copied from class:ClassVisitor
Visits the header of the class.- Overrides:
visit
in classClassVisitor
- Parameters:
version
- the class version. The minor version is stored in the 16 most significant bits, and the major version in the 16 least significant bits.access
- the class's access flags (seeOpcodes
). This parameter also indicates if the class is deprecated.name
- the internal name of the class (seeType.getInternalName()
).signature
- the signature of this class. May be null if the class is not a generic one, and does not extend or implement generic classes or interfaces.superName
- the internal of name of the super class (seeType.getInternalName()
). For interfaces, the super class isObject
. May be null, but only for theObject
class.interfaces
- the internal names of the class's interfaces (seeType.getInternalName()
). May be null.
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visitSource
public void visitSource(String file, String debug)
Description copied from class:ClassVisitor
Visits the source of the class.- Overrides:
visitSource
in classClassVisitor
- Parameters:
file
- the name of the source file from which the class was compiled. May be null.debug
- additional debug information to compute the correspondence between source and compiled elements of the class. May be null.
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visitModule
public ModuleVisitor visitModule(String name, int flags, String version)
Description copied from class:ClassVisitor
Visit the module corresponding to the class.- Overrides:
visitModule
in classClassVisitor
- Parameters:
name
- the fully qualified name (using dots) of the module.flags
- the module access flags, amongACC_OPEN
,ACC_SYNTHETIC
andACC_MANDATED
.version
- the module version, or null.- Returns:
- a visitor to visit the module values, or null if this visitor is not interested in visiting this module.
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visitNestHost
public void visitNestHost(String nestHost)
Description copied from class:ClassVisitor
Visits the nest host class of the class. A nest is a set of classes of the same package that share access to their private members. One of these classes, called the host, lists the other members of the nest, which in turn should link to the host of their nest. This method must be called only once and only if the visited class is a non-host member of a nest. A class is implicitly its own nest, so it's invalid to call this method with the visited class name as argument.- Overrides:
visitNestHost
in classClassVisitor
- Parameters:
nestHost
- the internal name of the host class of the nest.
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visitOuterClass
public void visitOuterClass(String owner, String name, String descriptor)
Description copied from class:ClassVisitor
Visits the enclosing class of the class. This method must be called only if the class has an enclosing class.- Overrides:
visitOuterClass
in classClassVisitor
- Parameters:
owner
- internal name of the enclosing class of the class.name
- the name of the method that contains the class, or null if the class is not enclosed in a method of its enclosing class.descriptor
- the descriptor of the method that contains the class, or null if the class is not enclosed in a method of its enclosing class.
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visitAnnotation
public AnnotationVisitor visitAnnotation(String descriptor, boolean visible)
Description copied from class:ClassVisitor
Visits an annotation of the class.- Overrides:
visitAnnotation
in classClassVisitor
- Parameters:
descriptor
- the class descriptor of the annotation class.visible
- true if the annotation is visible at runtime.- Returns:
- a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
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visitTypeAnnotation
public AnnotationVisitor visitTypeAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible)
Description copied from class:ClassVisitor
Visits an annotation on a type in the class signature.- Overrides:
visitTypeAnnotation
in classClassVisitor
- Parameters:
typeRef
- a reference to the annotated type. The sort of this type reference must beTypeReference.CLASS_TYPE_PARAMETER
,TypeReference.CLASS_TYPE_PARAMETER_BOUND
orTypeReference.CLASS_EXTENDS
. SeeTypeReference
.typePath
- the path to the annotated type argument, wildcard bound, array element type, or static inner type within 'typeRef'. May be null if the annotation targets 'typeRef' as a whole.descriptor
- the class descriptor of the annotation class.visible
- true if the annotation is visible at runtime.- Returns:
- a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
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visitAttribute
public void visitAttribute(Attribute attribute)
Description copied from class:ClassVisitor
Visits a non standard attribute of the class.- Overrides:
visitAttribute
in classClassVisitor
- Parameters:
attribute
- an attribute.
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visitNestMember
public void visitNestMember(String nestMember)
Description copied from class:ClassVisitor
Visits a member of the nest. A nest is a set of classes of the same package that share access to their private members. One of these classes, called the host, lists the other members of the nest, which in turn should link to the host of their nest. This method must be called only if the visited class is the host of a nest. A nest host is implicitly a member of its own nest, so it's invalid to call this method with the visited class name as argument.- Overrides:
visitNestMember
in classClassVisitor
- Parameters:
nestMember
- the internal name of a nest member.
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visitInnerClass
public void visitInnerClass(String name, String outerName, String innerName, int access)
Description copied from class:ClassVisitor
Visits information about an inner class. This inner class is not necessarily a member of the class being visited.- Overrides:
visitInnerClass
in classClassVisitor
- Parameters:
name
- the internal name of an inner class (seeType.getInternalName()
).outerName
- the internal name of the class to which the inner class belongs (seeType.getInternalName()
). May be null for not member classes.innerName
- the (simple) name of the inner class inside its enclosing class. May be null for anonymous inner classes.access
- the access flags of the inner class as originally declared in the enclosing class.
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visitField
public FieldVisitor visitField(int access, String name, String descriptor, String signature, Object value)
Description copied from class:ClassVisitor
Visits a field of the class.- Overrides:
visitField
in classClassVisitor
- Parameters:
access
- the field's access flags (seeOpcodes
). This parameter also indicates if the field is synthetic and/or deprecated.name
- the field's name.descriptor
- the field's descriptor (seeType
).signature
- the field's signature. May be null if the field's type does not use generic types.value
- the field's initial value. This parameter, which may be null if the field does not have an initial value, must be anInteger
, aFloat
, aLong
, aDouble
or aString
(forint
,float
,long
orString
fields respectively). This parameter is only used for static fields. Its value is ignored for non static fields, which must be initialized through bytecode instructions in constructors or methods.- Returns:
- a visitor to visit field annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes.
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visitMethod
public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions)
Description copied from class:ClassVisitor
Visits a method of the class. This method must return a newMethodVisitor
instance (or null) each time it is called, i.e., it should not return a previously returned visitor.- Overrides:
visitMethod
in classClassVisitor
- Parameters:
access
- the method's access flags (seeOpcodes
). This parameter also indicates if the method is synthetic and/or deprecated.name
- the method's name.descriptor
- the method's descriptor (seeType
).signature
- the method's signature. May be null if the method parameters, return type and exceptions do not use generic types.exceptions
- the internal names of the method's exception classes (seeType.getInternalName()
). May be null.- Returns:
- an object to visit the byte code of the method, or null if this class visitor is not interested in visiting the code of this method.
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visitEnd
public void visitEnd()
Description copied from class:ClassVisitor
Visits the end of the class. This method, which is the last one to be called, is used to inform the visitor that all the fields and methods of the class have been visited.- Overrides:
visitEnd
in classClassVisitor
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