关于JAVA反射
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2024-01-21 18:01:10
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项目中有个需求需要实现指定属性的名称取出属性值,回忆了一下记得springside里边有个工具类直接就能侵犯对象隐私。。。嘿嘿
翻出来留念,yeah~茄子!
翻出来留念,yeah~茄子!
package org.springside.modules.utils;
import java.lang.reflect.Field;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.Assert;
/**
* 反射的Utils函数集合.
*
* 提供侵犯隐私的直接读取filed的能力.
*/
public class BeanUtils {
protected static Logger logger = LoggerFactory.getLogger(BeanUtils.class);
private BeanUtils() {
}
/**
* 直接读取对象属性值,无视private/protected修饰符,不经过getter函数.
*/
public static Object getFieldValue(Object object, String fieldName) throws NoSuchFieldException {
Field field = getDeclaredField(object, fieldName);
if (!field.isAccessible()) {
field.setAccessible(true);
}
Object result = null;
try {
result = field.get(object);
} catch (IllegalAccessException e) {
logger.error("不可能抛出的异常{}", e.getMessage());
}
return result;
}
/**
* 直接设置对象属性值,无视private/protected修饰符,不经过setter函数.
*/
public static void setFieldValue(Object object, String fieldName, Object value) throws NoSuchFieldException {
Field field = getDeclaredField(object, fieldName);
if (!field.isAccessible()) {
field.setAccessible(true);
}
try {
field.set(object, value);
} catch (IllegalAccessException e) {
logger.error("不可能抛出的异常:{}", e.getMessage());
}
}
/**
* 循环向上转型,获取对象的DeclaredField.
*/
public static Field getDeclaredField(Object object, String fieldName) throws NoSuchFieldException {
Assert.notNull(object);
return getDeclaredField(object.getClass(), fieldName);
}
/**
* 循环向上转型,获取类的DeclaredField.
*/
@SuppressWarnings("unchecked")
public static Field getDeclaredField(Class clazz, String fieldName) throws NoSuchFieldException {
Assert.notNull(clazz);
Assert.hasText(fieldName);
for (Class superClass = clazz; superClass != Object.class; superClass = superClass.getSuperclass()) {
try {
return superClass.getDeclaredField(fieldName);
} catch (NoSuchFieldException e) {
// Field不在当前类定义,继续向上转型
}
}
throw new NoSuchFieldException("No such field: " + clazz.getName() + '.' + fieldName);
}
}