How to get method parameter names?

如何获取方法参数命名？

1.通过javassist获取

/**
* Get Method Parameter Names in JAVA
* 参考：http://blog.hailinzeng.com/2014/10/10/get-method-parameter-name-in-java/
*
* @param clazz
* @param method
* @return 参数名称数组
*/
public static String[] getMethodParamNames(Class<?> clazz, Method method) throws NotFoundException {
ClassPool pool = ClassPool.getDefault();
pool.insertClassPath(new ClassClassPath(clazz));
CtClass cc = pool.get(clazz.getName());
Class<?>[] paramTypes = method.getParameterTypes();
String[] paramTypeNames = new String[method.getParameterTypes().length];
for (int i = 0; i < paramTypes.length; i++)
paramTypeNames[i] = paramTypes[i].getName();
CtMethod cm = cc.getDeclaredMethod(method.getName(), pool.get(paramTypeNames));

MethodInfo methodInfo = cm.getMethodInfo();
CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute
.getAttribute(LocalVariableAttribute.tag);
if (attr == null) {
throw new RuntimeException("class:" + clazz.getName()
+ ", have no LocalVariableTable, please use javac -g:{vars} to compile the source file");
}

String[] paramNames = new String[cm.getParameterTypes().length];
TreeMap<Integer, Integer> map = new TreeMap<>();
for (int i = 0; i < attr.tableLength(); i++) {
map.put(attr.index(i), i);
}
int index = 0;
boolean isStaticMethod = Modifier.isStatic(cm.getModifiers());
boolean flag = false;
for (Integer key : map.keySet()) {
//如果是非静态方法，第0个attr.variableName(0)返回this,所以要跳过
if (!isStaticMethod && !flag) {
flag = true;
continue;
}

if (index < paramNames.length) {
paramNames[index++] = attr.variableName(map.get(key));
} else {
break;
}
}
return paramNames;
}

2.java8 可直接使用java.lang.reflect.Parameter#getName()获取参数命名