java反射访问私有成员变量

public class ReflectTest {
private volatile String name = "before";

public void setName(String name) {
this.name = name;
}

public static void main(String[] args) {
ReflectTest test = new ReflectTest();

try {
System.out.println(getValue(test, "name"));
test.setName("after");
System.out.println(getValue(test, "name"));
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
}

}

public static Object getValue(Object instance, String fieldName) throws IllegalAccessException,
NoSuchFieldException {

Field field = getField(instance.getClass(), fieldName);
// 参数值为true，禁用访问控制检查
field.setAccessible(true);
return field.get(instance);
}

public static Field getField(Class thisClass, String fieldName) throws NoSuchFieldException {

if (fieldName == null) {
throw new NoSuchFieldException("Error field !");
}

Field field = thisClass.getDeclaredField(fieldName);
return field;
}
}

before
after