ASM4 读取java类注解-白红宇

ASM4 读取java类注解

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发布时间：2019-06-29

本文共 2764 字，大约阅读时间需要 9 分钟。

package hello.asm.my;import hello.asm.bean.User;import java.io.IOException;import java.lang.reflect.InvocationTargetException;import java.sql.Connection;import java.util.ArrayList;import java.util.Collections;import java.util.HashMap;import java.util.List;import java.util.Map;import org.objectweb.asm.AnnotationVisitor;import org.objectweb.asm.Attribute;import org.objectweb.asm.ClassReader;import org.objectweb.asm.ClassVisitor;import org.objectweb.asm.ClassWriter;import org.objectweb.asm.FieldVisitor;import org.objectweb.asm.MethodVisitor;import org.objectweb.asm.Opcodes;import org.objectweb.asm.Type;import org.objectweb.asm.tree.AnnotationNode;import org.objectweb.asm.tree.ClassNode;public class Hello extends ClassLoader implements Opcodes{	public static void main(String[] args) throws IllegalArgumentException, SecurityException, IllegalAccessException, InvocationTargetException, IOException {	    String n = User.class.getName();	    ClassReader cr = new ClassReader(n);	    final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);	    	    ClassNode cn =  new ClassNode();	    cr.accept(cn, ASM4);	    final List
    
      nlist = cn.visibleAnnotations;	    	    	    cr.accept(new ClassVisitor(ASM4,cw) {		@Override		public AnnotationVisitor visitAnnotation(String desc,			boolean visible) {		    AnnotationNode an = new AnnotationNode(desc);		    nlist.add(an);		    return an;		}	    }, 2);	    	    for (AnnotationNode annotationNode : nlist) {		List vl = annotationNode.values;		System.out.println(vl.get(0).toString() + vl.get(1));	    }	}		}

package hello.asm.bean;@Table(name="BASE_USER")@Encode("utf-8")public class User {    	@Column(name = "name")	private String name = "loowj";    	@Column(name = "id")	private String id = "001";		/**	 * 构造函数1	 */	public User(String id,String name) {	}	public User(String name){	}	private User(){}		public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public String getId() {		return id;	}	public void setId(String id) {		this.id = id;	}	public void getUser(){		System.out.println(this.id + "   " +this.name);	}	}

package hello.asm.bean;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)public   Table {    public String name();}

package hello.asm.bean;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;@Target(value={ElementType.TYPE,ElementType.FIELD})@Retention(RetentionPolicy.RUNTIME)public   Encode {    String value();}