Class ASMifierClassVisitor

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:

• write the Java source code equivalent to the bytecode you want to generate;
• compile it with javac;
• make a ASMifierClassVisitor visit this compiled class (see the main method);
• edit the generated source code, if necessary.

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");
   }
 }
 

public ASMifierClassVisitor(PrintWriter pw)

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

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

public void visitAttribute(Attribute attr)

public void visitEnd()

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

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

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