org.objectweb.asm.util
Class DumpClassVisitor

java.lang.Object
  |
  +--org.objectweb.asm.util.PrintClassVisitor
        |
        +--org.objectweb.asm.util.DumpClassVisitor
All Implemented Interfaces:
ClassVisitor

public class DumpClassVisitor
extends PrintClassVisitor

A PrintClassVisitor that prints the ASM code that generates the classes it visits. This class visitor can be used to quickly write ASM code to generate some given bytecode:

The source code printed when visiting the Hello class is the following:
 import org.objectweb.asm.*;
 import java.io.FileOutputStream;

 public class Dump implements Constants {

 public static void main (String[] args) throws Exception {

 ClassWriter cw = new ClassWriter(false);
 CodeVisitor cv;

 cw.visit(ACC_PUBLIC + ACC_SUPER, "Hello", "java/lang/Object", null, "Hello.java");

 {
 cv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "main", "([Ljava/lang/String;)V", null);
 cv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
 cv.visitLdcInsn("hello");
 cv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V");
 cv.visitInsn(RETURN);
 cv.visitMaxs(2, 1);
 }
 {
 cv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null);
 cv.visitVarInsn(ALOAD, 0);
 cv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
 cv.visitInsn(RETURN);
 cv.visitMaxs(1, 1);
 }
 cw.visitEnd();

 FileOutputStream os = new FileOutputStream("Dumped.class");
 os.write(cw.toByteArray());
 os.close();
 }
 }
 
where Hello is defined by:
 public class Hello {

   public static void main (String[] args) {
     System.out.println("hello");
   }
 }
 


Fields inherited from class org.objectweb.asm.util.PrintClassVisitor
dump, pw
 
Constructor Summary
DumpClassVisitor(PrintWriter pw)
          Constructs a new DumpClassVisitor object.
 
Method Summary
static void main(String[] args)
          Prints the ASM source code to generate the given class to the standard output.
 PrintCodeVisitor printMethod(int access, String name, String desc, String[] exceptions)
           
 void visit(int access, String name, String superName, String[] interfaces, String sourceFile)
          Visits the header of the class.
 void visitEnd()
          Visits the end of the class.
 void visitField(int access, String name, String desc, Object value)
          Visits a field of the class.
 void visitInnerClass(String name, String outerName, String innerName, int access)
          Visits information about an inner class.
 
Methods inherited from class org.objectweb.asm.util.PrintClassVisitor
visitMethod
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DumpClassVisitor

public DumpClassVisitor(PrintWriter pw)
Constructs a new DumpClassVisitor object.
Parameters:
pw - the print writer to be used to print the trace.
Method Detail

main

public static void main(String[] args)
                 throws Exception
Prints the ASM source code to generate the given class to the standard output.

Usage: DumpClassVisitor <fully qualified class name>


visit

public void visit(int access,
                  String name,
                  String superName,
                  String[] interfaces,
                  String sourceFile)
Description copied from interface: ClassVisitor
Visits the header of the class.
Following copied from interface: org.objectweb.asm.ClassVisitor
Parameters:
access - the class's access flags (see Constants). This parameter also indicates if the class is deprecated.
name - the internal name of the class (see getInternalName).
superName - the internal of name of the super class (see getInternalName). For interfaces, the super class is Object.
interfaces - the internal names of the class's interfaces (see getInternalName). May be null.
sourceFile - the name of the source file from which this class was compiled. May be null.

visitInnerClass

public void visitInnerClass(String name,
                            String outerName,
                            String innerName,
                            int access)
Description copied from interface: ClassVisitor
Visits information about an inner class. This inner class is not necessarily a member of the class being visited.
Following copied from interface: org.objectweb.asm.ClassVisitor
Parameters:
name - the internal name of an inner class (see getInternalName).
outerName - the internal name of the class to which the inner class belongs (see getInternalName). May be null.
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.

visitField

public void visitField(int access,
                       String name,
                       String desc,
                       Object value)
Description copied from interface: ClassVisitor
Visits a field of the class.
Following copied from interface: org.objectweb.asm.ClassVisitor
Parameters:
access - the field's access flags (see Constants). This parameter also indicates if the field is synthetic and/or deprecated.
name - the field's name.
desc - the field's descriptor (see Type).
value - the field's initial value. This parameter, which may be null if the field does not have an initial value, must be an Integer, a Float, a Long, a Double or a String.

printMethod

public PrintCodeVisitor printMethod(int access,
                                    String name,
                                    String desc,
                                    String[] exceptions)
Overrides:
printMethod in class PrintClassVisitor

visitEnd

public void visitEnd()
Description copied from interface: 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 class PrintClassVisitor