反射工具类，通过getMethod和setMethod进行操作

private static final String SETTER_PREFIX = "set";

private static final String GETTER_PREFIX = "get";

private static final String CGLIB_CLASS_SEPARATOR = "$$";

/**
* 调用Getter方法.
* 支持多级，如：对象名.对象名.方法
*/
public static Object invokeGetter(Object obj, String propertyName) {
Object object = obj;
for (String name : StringUtils.split(propertyName, ".")) {
String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(name);
object = invokeMethod(object, getterMethodName, new Class[]{}, new Object[]{});
}
return object;
}

通过此方法可以调用实体的get方法，可以支持级联，用法比如：

Student student = new Student();
student.setStudentName("zhangshan");
User user = new User();
user.setStudent(student);
String studentName = (String) Reflections.invokeGetter(user,"student.studentName");
System.out.println(studentName);

二，通过setMethod，写入参数

/**
* 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.
* 如向上转型到Object仍无法找到, 返回null.
* 匹配函数名+参数类型。
* <p/>
* 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
*/
public static Method getAccessibleMethod(final Object obj, final String methodName,
final Class<?>... parameterTypes) {
Validate.notNull(obj, "object can't be null");
Validate.notBlank(methodName, "methodName can't be blank");

for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
try {
Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
makeAccessible(method);
return method;
} catch (NoSuchMethodException e) {
// Method不在当前类定义,继续向上转型
continue;// new add
}
}
return null;
}

/**
* 直接调用对象方法, 无视private/protected修饰符.
* 用于一次性调用的情况，否则应使用getAccessibleMethod()函数获得Method后反复调用.
* 同时匹配方法名+参数类型，
*/
public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,
final Object[] args) {
Method method = getAccessibleMethod(obj, methodName, parameterTypes);
if (method == null) {
throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
}

try {
return method.invoke(obj, args);
} catch (Exception e) {
throw convertReflectionExceptionToUnchecked(e);
}
}

/**
* 直接调用对象方法, 无视private/protected修饰符，
* 用于一次性调用的情况，否则应使用getAccessibleMethodByName()函数获得Method后反复调用.
* 只匹配函数名，如果有多个同名函数调用第一个。
*/
public static Object invokeMethodByName(final Object obj, final String methodName, final Object[] args) {
Method method = getAccessibleMethodByName(obj, methodName);
if (method == null) {
throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
}

try {
return method.invoke(obj, args);
} catch (Exception e) {
throw convertReflectionExceptionToUnchecked(e);
}
}

/**
* 调用Setter方法, 仅匹配方法名。
* 支持多级，如：对象名.对象名.方法
*/
public static void invokeSetter(Object obj, String propertyName, Object value) {
Object object = obj;
String[] names = StringUtils.split(propertyName, ".");
for (int i = 0; i < names.length; i++) {
if (i < names.length - 1) {
String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(names[i]);
object = invokeMethod(object, getterMethodName, new Class[]{}, new Object[]{});
} else {
String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(names[i]);
invokeMethodByName(object, setterMethodName, new Object[]{value});
}
}
}

用法如下：

Student student = new Student();
User user = new User();
user.setStudent(student);
Reflections.invokeSetter(user,"student.studentName","hehe");
String studentName = user.getStud().getStudentName();
System.out.println(studentName);