org.objectweb.asm.util

Class TraceClassVisitor

public class TraceClassVisitor extends TraceAbstractVisitor implements ClassVisitor

A {@link ClassVisitor} that prints a disassembled view of the classes it visits. This class visitor can be used alone (see the {@link #main main} method) to disassemble a class. It can also be used in the middle of class visitor chain to trace the class that is visited at a given point in this chain. This may be uselful for debugging purposes.

The trace printed when visiting the Hello class is the following:

 // class version 49.0 (49)
 // access flags 33
 public class Hello {

  // compiled from: Hello.java

   // access flags 1
   public <init> ()V
     ALOAD 0
     INVOKESPECIAL java/lang/Object <init> ()V
     RETURN
     MAXSTACK = 1
     MAXLOCALS = 1

   // access flags 9
   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");
     }
 }
 

Author: Eric Bruneton Eugene Kuleshov

Field Summary
protected ClassVisitorcv
The {@link ClassVisitor} to which this visitor delegates calls.
protected PrintWriterpw
The print writer to be used to print the class.
Constructor Summary
TraceClassVisitor(PrintWriter pw)
Constructs a new {@link TraceClassVisitor}.
TraceClassVisitor(ClassVisitor cv, PrintWriter pw)
Constructs a new {@link TraceClassVisitor}.
Method Summary
protected TraceFieldVisitorcreateTraceFieldVisitor()
protected TraceMethodVisitorcreateTraceMethodVisitor()
static voidmain(String[] args)
Prints a disassembled view of the given class to the standard output.
voidvisit(int version, int access, String name, String signature, String superName, String[] interfaces)
AnnotationVisitorvisitAnnotation(String desc, boolean visible)
voidvisitAttribute(Attribute attr)
voidvisitEnd()
FieldVisitorvisitField(int access, String name, String desc, String signature, Object value)
voidvisitInnerClass(String name, String outerName, String innerName, int access)
MethodVisitorvisitMethod(int access, String name, String desc, String signature, String[] exceptions)
voidvisitOuterClass(String owner, String name, String desc)
voidvisitSource(String file, String debug)

Field Detail

cv

protected final ClassVisitor cv
The {@link ClassVisitor} to which this visitor delegates calls. May be null.

pw

protected final PrintWriter pw
The print writer to be used to print the class.

Constructor Detail

TraceClassVisitor

public TraceClassVisitor(PrintWriter pw)
Constructs a new {@link TraceClassVisitor}.

Parameters: pw the print writer to be used to print the class.

TraceClassVisitor

public TraceClassVisitor(ClassVisitor cv, PrintWriter pw)
Constructs a new {@link TraceClassVisitor}.

Parameters: cv the {@link ClassVisitor} to which this visitor delegates calls. May be null. pw the print writer to be used to print the class.

Method Detail

createTraceFieldVisitor

protected TraceFieldVisitor createTraceFieldVisitor()

createTraceMethodVisitor

protected TraceMethodVisitor createTraceMethodVisitor()

main

public static void main(String[] args)
Prints a disassembled view of the given class to the standard output.

Usage: TraceClassVisitor [-debug] <fully qualified class name or class file name >

Parameters: args the command line arguments.

Throws: Exception if the class cannot be found, or if an IO exception occurs.

visit

public void visit(int version, int access, String name, String signature, String superName, String[] interfaces)

visitAnnotation

public AnnotationVisitor visitAnnotation(String desc, boolean visible)

visitAttribute

public void visitAttribute(Attribute attr)

visitEnd

public void visitEnd()

visitField

public FieldVisitor visitField(int access, String name, String desc, String signature, Object value)

visitInnerClass

public void visitInnerClass(String name, String outerName, String innerName, int access)

visitMethod

public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions)

visitOuterClass

public void visitOuterClass(String owner, String name, String desc)

visitSource

public void visitSource(String file, String debug)