org.objectweb.asm.util

Class ASMifierClassVisitor

public class ASMifierClassVisitor extends PrintClassVisitor

A {@link PrintClassVisitor 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, 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, 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");
   }
 }
 

Author: Eric Bruneton, Eugene Kuleshov

Constructor Summary
ASMifierClassVisitor(PrintWriter pw)
Constructs a new {@link ASMifierClassVisitor} object.
Method Summary
static voidmain(String[] args)
Prints the ASM source code to generate the given class to the standard output.
voidvisit(int version, int access, String name, String superName, String[] interfaces, String sourceFile)
voidvisitAttribute(Attribute attr)
voidvisitEnd()
voidvisitField(int access, String name, String desc, Object value, Attribute attrs)
voidvisitInnerClass(String name, String outerName, String innerName, int access)
CodeVisitorvisitMethod(int access, String name, String desc, String[] exceptions, Attribute attrs)

Constructor Detail

ASMifierClassVisitor

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

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

Method Detail

main

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

Usage: ASMifierClassVisitor [-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 superName, String[] interfaces, String sourceFile)

visitAttribute

public void visitAttribute(Attribute attr)

visitEnd

public void visitEnd()

visitField

public void visitField(int access, String name, String desc, Object value, Attribute attrs)

visitInnerClass

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

visitMethod

public CodeVisitor visitMethod(int access, String name, String desc, String[] exceptions, Attribute attrs)