BeanUtils的 - '描述' 方法返回的InvocationTargetException

Question

我试图在地图中获取以下实体的属性：

@Entity 
@Table(name = "ps_parameter") 
@NamedQueries({Named Queries Here..}) 
public class PSParameter 
    implements Serializable 
{ 
    //~ Static variables/initializers ---------------------------------------------------- 
    .... 

    //~ Instance variables --------------------------------------------------------------- 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id", nullable = false) 
    private Integer id; 

    @Column(name = "name", nullable = false) 
    private String name; 

    @Column(name = "paramValue", nullable = false) 
    private String paramValue; 

    //~ Constructors --------------------------------------------------------------------- 
    .... 

    //~ Methods -------------------------------------------------------------------------- 
    public Double getDoubleValue() 
    { 
     return Double.parseDouble(getParamValue()); 
    } 

    public Integer getIntegerValue() 
    { 
     return Integer.parseInt(getParamValue()); 
    } 
    .... 
} 

通过如下：

.... 
try 
    { 
    Map propertiesCurrentObject = BeanUtils.describe(currentObject); 
    .... 
    } 
.... 

显然currentObject是PSParameter ..

每当describe函数被调用时，我得到一个InvocationTargetException：

java.lang.reflect.InvocationTargetException 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:616) 
    at org.apache.commons.beanutils.PropertyUtilsBean.invokeMethod(PropertyUtilsBean.java:2170) 
    at org.apache.commons.beanutils.PropertyUtilsBean.getSimpleProperty(PropertyUtilsBean.java:1332) 
    at org.apache.commons.beanutils.PropertyUtilsBean.getNestedProperty(PropertyUtilsBean.java:770) 
    at org.apache.commons.beanutils.BeanUtilsBean.getNestedProperty(BeanUtilsBean.java:715) 
    at org.apache.commons.beanutils.BeanUtilsBean.getProperty(BeanUtilsBean.java:741) 
    at org.apache.commons.beanutils.BeanUtilsBean.describe(BeanUtilsBean.java:514) 
    at org.apache.commons.beanutils.BeanUtils.describe(BeanUtils.java:185) 
    at xxx.yyy.ejb.core.facade.AuditEntryFacade.getChangesBetweenTwoObjects(AuditEntryFacade.java:1198) 
.... 

谁根源如下：

Caused by: java.lang.NumberFormatException: For input string: "true" 
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) 
    at java.lang.Integer.parseInt(Integer.java:481) 
    at java.lang.Integer.parseInt(Integer.java:514) 
    at xxx.yyy.ejb.core.entity.PSParameter.getIntegerValue(PSParameter.java:169) 
    ... 87 more 

任何提示，为何会出现这种情况？我的意思是，对我来说，清楚这个异常的根本原因，不能将字符串解析为整数，但为什么BeanUtils及其描述了这样做？

无论如何绕过这个，或任何其他的？谢谢！

Answer 1

从Javadoc：

返回整个组属性的的量，指定Bean提供的读取方法。此地图包含的到字符串转换属性值针对其提供

这意味着describe()方法返回从属性映射到给定的bean的属性值的读取方法的所有性能，主叫吸气剂，以获得后者。这意味着当调用describe()时，你的获得者都不应该抛出异常。