实现ClassVisitor接口

package com.uwo.resources.asm.test;import org.objectweb.asm.*;/*** Created by yanhao on 2017/5/15.*/
public class UwoClassVisitor implements ClassVisitor{public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {System.out.println("visit");}public void visitOuterClass(String owner, String name, String desc) {System.out.println("visitOuterClass");}public void visitInnerClass(String name, String outerName, String innerName, int access) {System.out.println("visitInnerClass");}public void visitAttribute(Attribute attr) {System.out.println("visitAttribute");}public void visitSource(String source, String debug) {System.out.println("visitSource");}public AnnotationVisitor visitAnnotation(String desc, boolean visible) {System.out.println("Annotation===========start==========");System.out.println("Annotation desc = " + desc);System.out.println("Annotation visible = " + visible);System.out.println("Annotation===========end==========");return null;}public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {System.out.println("Field===========start==========");System.out.println("Field access = " + access);System.out.println("Field name = " + name);System.out.println("Field desc = " + desc);System.out.println("Field signature = " + signature);System.out.println("Field value = " + value);System.out.println("Field===========end==========");return null;}public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {System.out.println("Method===========start==========");System.out.println("Method access = " + access);System.out.println("Method name = " + name);System.out.println("Method desc = " + desc);System.out.println("Method signature = " + signature);System.out.println("Method exceptions = " + exceptions);System.out.println("Method===========end==========");return null;}public void visitEnd() {System.out.println("visitEnd");}
}

执行代码

try {ClassReader cr = new ClassReader(Uwo.class.getName());cr.accept(new UwoClassVisitor(), 0);
} catch (IOException e) {e.printStackTrace();
}

执行结果

visit
visitSource
Field===========start==========
Field access = 4
Field name = name
Field desc = Ljava/lang/String;
Field signature = null
Field value = null
Field===========end==========
Field===========start==========
Field access = 4
Field name = sex
Field desc = Ljava/lang/Integer;
Field signature = null
Field value = null
Field===========end==========
Method===========start==========
Method access = 1
Method name = <init>
Method desc = (Ljava/lang/String;)V
Method signature = null
Method exceptions = null
Method===========end==========
Method===========start==========
Method access = 1
Method name = hello
Method desc = (Ljava/lang/String;)Ljava/lang/String;
Method signature = null
Method exceptions = null
Method===========end==========
Method===========start==========
Method access = 1
Method name = run
Method desc = ()V
Method signature = null
Method exceptions = null
Method===========end==========
visitEnd