/**
* `获取给定对象的属性的值` `@param fieldName 属性名` `@param obj 对象`
*
* @return
*/
public static Object getFieldValue(String fieldName, Object obj) {
try {
Class cls = obj.getClass();
Field field = cls.getDeclaredField(fieldName);
return field.get(obj);
} catch (Exception e) {
e.printStackTrace();
print("Field access error!");
throw new RuntimeException(e);
}
}
/** Reflect operations demo */
public static void reflect(Object obj) {
// `cls用于描述对象所属的类`
Class cls = obj.getClass();
print("Class Name: " + cls.getCanonicalName());
// `fields包含对象的所有属性`
Field[] fields = cls.getDeclaredFields();
print("List of fields:");
for (Field f : fields) {
print(String.format("%30s %15s", f.getType(), f.getName()));
}
// `methods包含对象的所有方法`
Method[] methods = cls.getDeclaredMethods();
print("List of methods:");
for (Method m : methods)
print(
String.format(
"%30s %15s %30s",
m.getReturnType(), m.getName(), Arrays.toString(m.getParameterTypes())));
Constructor[] constructors = cls.getConstructors();
print("List of contructors:");
for (Constructor c : constructors)
print(String.format("%30s %15s", c.getName(), Arrays.toString(c.getParameterTypes())));
}