利用Javassist获取Java类中的方法参数名、参数类型、方法访问类型

http://www.csg.is.titech.ac.jp/~chiba/javassist/

package com.vl;



import java.lang.reflect.Method;



import javassist.ClassPool;

import javassist.CtClass;

import javassist.CtMethod;

import javassist.Modifier;

import javassist.NotFoundException;

import javassist.bytecode.AccessFlag;

import javassist.bytecode.CodeAttribute;

import javassist.bytecode.LocalVariableAttribute;

import javassist.bytecode.MethodInfo;



import com.vl.app.PTZ;

import com.vl.app.StreamsUtil;

import com.vl.sql.UserDAO;



public class VLInterface {





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

		ClassPool pool = ClassPool.getDefault();



		Class[] cs = new Class[] { PTZ.class, UserDAO.class ,StreamsUtil.class};

		String[] prefixStrings = new String[] { "ptz", "user" ,"streamsutil"};

		for (int i = 0; i < cs.length; i++) {

			CtClass ctClass;

			Class clz = cs[i];



			ctClass = pool.get(clz.getName());



			Method[] methods = clz.getDeclaredMethods();



			for (Method m : methods) {

				String name = m.getName();

				CtMethod cm = ctClass.getDeclaredMethod(name);

				MethodInfo methodInfo = cm.getMethodInfo();

				Class[] parameterTypes = m.getParameterTypes();

				CodeAttribute codeAttribute = methodInfo.getCodeAttribute();

				LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute

						.getAttribute(LocalVariableAttribute.tag);

				if (attr == null) {

					// exception

				}

				if(cm.getMethodInfo().getAccessFlags()!=AccessFlag.PUBLIC)continue;

				//System.out.println();

				String[] paramNames = new String[cm.getParameterTypes().length];

				int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;

				for (int j = 0; j < paramNames.length; j++)

					paramNames[j] = attr.variableName(j + pos);

				// paramNames即参数名



				System.out.printf("\"%s.%s\":\r\n\tReturn:%s\t(Parameters ",

						prefixStrings[i], name, m.getReturnType().getSimpleName());

				for (int i1 = 0; i1 < paramNames.length; i1++) {

					

					System.out.printf("%d:[%s %s] ", i1+1, parameterTypes[i1]

							.getSimpleName(), paramNames[i1]);

				}

				// for (Class class1 : parameterTypes) {

				// System.out.printf("[%s],", class1.getName());

				// }

				System.out.println(")\r\n");

			}

		}

	}

}