java 尝试获取简单的属性值时 PropertyUtils.getProperty 失败
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PropertyUtils.getProperty fails when trying to get a simple property value
提问by nadouani
I've a strange issue with the PropertyUtils.getProperty(bean, fieldName)method, where I got a java.lang.NoShuchMethodException.
我的PropertyUtils.getProperty(bean, fieldName)方法有一个奇怪的问题，我得到了一个java.lang.NoShuchMethodException.
Suppose we have a simple java class called pojo:
假设我们有一个名为 pojo 的简单 java 类：
public class Pojo {
public java.util.Date aDate;
public java.util.Date theDate;
public Pojo(){}
}
and a caller class like
和一个呼叫者类
public class TestPojo{
public static void main(String[] args){
Pojo p = new Pojo();
p.setADate(new Date());
p.setTheDate(new Date());
PropertyUtils.getProperty(p, "theDate");
PropertyUtils.getProperty(p, "aDate");
}
}
The first PropertyUtils.getPropertycall works fine, and the second one will throwthe NoSuchMethodExeption.
第一次PropertyUtils.getProperty调用工作正常，而第二个会throw的NoSuchMethodExeption。
I would like to know if I'm missing something stupid or it's really a bug :)
我想知道我是否遗漏了一些愚蠢的东西或者它真的是一个错误:)
采纳答案by Fred
I don't understand how PropertyUtils.getProperty(p, "TheDate");could work since the name of the property is not correct.
我不明白如何PropertyUtils.getProperty(p, "TheDate");工作，因为属性的名称不正确。
Try this:
试试这个：
public class TestPojo{
public static void main(String[] args){
Pojo p = new Pojo();
p.setADate(new Date());
p.setTheDate(new Date());
PropertyUtils.getProperty(p, "theDate");
PropertyUtils.getProperty(p, "aDate");
}
}
Link to the PropertyUtils method
To Solve your problem, two solutions:
要解决您的问题，有两种解决方案：
- use property name "ADate" instead
- change your accessors method names to getaDate() and setaDate(Date dateToSet)
- 改用属性名称“ADate”
- 将访问器方法名称更改为 getaDate() 和 setaDate(Date dateToSet)
As Xavi said it is a reported bug
正如哈维所说，这是一个已报告的错误
回答by Xavi López
Take a look at this bug report
看看这个错误报告
The Java Bean Specification states in section "8.8 Capitalization of inferred names" that when the first character is converted to lowercase unless the first two characters are both uppercase then the property name is "unchanged".
Java Bean 规范在“8.8 推断名称的大写”一节中指出，当第一个字符被转换为小写时，除非前两个字符都是大写，那么属性名称是“不变的”。
Adapting the rest for you (in italics):
为您调整其余部分（斜体）：
So when you have a getter method named "getADate"this is translated into property name "ADate"and not "aDate".
So to resolve your issue you have two choices:
- use property name "ADate"instead or
- change you method names to "getaDate"and "setaDate"
因此，当您有一个名为"getADate"的 getter 方法时，它会被转换为属性名称"ADate"而不是"aDate"。
因此，要解决您的问题，您有两种选择：
- 使用属性名称“ADate”代替或
- 将您的方法名称更改为“getaDate”和“setaDate”
回答by Ankar
May be you need using:
可能你需要使用：
PropertyUtils.getProperty(p, "ADate");
where A in UPPERCASE
其中 A 大写
回答by Jesper
Try
尝试
PropertyUtils.getProperty(p, "ADate");
instead of
代替
PropertyUtils.getProperty(p, "aDate");
