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");
			}
		}
	}
}