布尔字段的Java Bean规范

Question

I have Java bean with the field activeRecord

private Boolean activeRecord;

@Override
public Boolean isActiveRecord() {
    return activeRecord;
}

@Override
public void setActiveRecord(Boolean activeRecord) {
    this.activeRecord = activeRecord;
}

when I send it in List as Jasper Report data source

List<Branch> dataList = new BranchLogic().selectAll();
JRBeanCollectionDataSource beanColDataSource = new JRBeanCollectionDataSource(dataList);

I get the error message

net.sf.jasperreports.engine.JRException: Error retrieving field value from bean: activeRecord. .... Caused by: java.lang.NoSuchMethodException: Property 'activeRecord' has no getter method in class 'class com.tawaak.app.data.domain.model.branch.Branch'

Why Jasper doesn't recognize the isActiveRecord as a getter method?

Answer 1

The prefix is... can be used for methods that return a primitive boolean . However, your field activeRecord is of type Boolean , which is an object (the wrapper type of boolean ), and for objects you always need to use get... .

From the JavaBeans specification , 8.3.2:

In addition, for boolean properties, we allow a getter method to match the pattern:

 public boolean is<PropertyName>(); 

This is<PropertyName> method may be provided instead of a get<PropertyName> method, or it may be provided in addition to a get<PropertyName> method.

As such, you have two possible fix:

• Make your activeRecord a boolean and keep the getter isActiveRecord() . This would be the preferred approach if activeRecord cannot be null .
• Keep it as a Boolean , but rename your method isActiveRecord() to getActiveRecord() . You'll need to make sure the caller handles null properly.