Name: jl125535 Date: 11/06/2003
FULL PRODUCT VERSION :
All 1.4.x releases.
FULL OS VERSION :
Applicable to all.
A DESCRIPTION OF THE PROBLEM :
The DefaultPersistenceDelegate does not correctly search for boolean properties if they are in a superclass. The following code (line 162 in 1.4.2) illustrates the problem:
constructorArgs[i] = (f != null && !Modifier.isStatic(f.getModifiers())) ?
f.get(oldInstance) :
type.getMethod("get"+capitalize(name), new Class[0]).invoke(oldInstance, new Object[0]);
In the case that type == boolean/Boolean, the code should check for "is"+capatalize(name) and then fall back on "get" if that fails.
Section 8.3.2 of the JavaBeans Specification at http://java.sun.com/products/javabeans/docs/spec.html describes the "is<PropertyName>" naming pattern for boolean properties.
STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the test case.
REPRODUCIBILITY :
This bug can be reproduced always.
---------- BEGIN SOURCE ----------
import java.beans.XMLEncoder;
import java.beans.DefaultPersistenceDelegate;
import java.io.ByteArrayOutputStream;
public class DefaultPersistenceDelegateBug {
public static class SuperBean {
private boolean condition;
public SuperBean(boolean condition) {
this.condition = condition;
}
public boolean isCondition() {
return condition;
}
}
public static class SubBean extends SuperBean {
public SubBean(boolean condition) {
super(condition);
}
}
public static void main(String[] args) {
XMLEncoder encoder = new XMLEncoder(new ByteArrayOutputStream());
encoder.setPersistenceDelegate(SubBean.class, new DefaultPersistenceDelegate(new String[]{"condition"}));
encoder.writeObject(new SubBean(true));
}
}
---------- END SOURCE ----------
CUSTOMER SUBMITTED WORKAROUND :
If you have access to your beans, then you can add/change your boolean getter to be in "get" pattern instead of the "is" pattern.
(Incident Review ID: 207880)
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Name: jl125535 Date: 11/06/2003
DESCRIPTION OF THE PROBLEM :
Below is a test case. I have two classes that I want to persist.
Test1 has a boolean value that is set by the constructor and can be accessed by isSomething().
Test2 extends Test1 and adds some more behaviour.
To persist objects of both classes I create an XMLEncoder and add DefaultPersistenceDelegate's for both classes, telling them that they should get the value of the something-attribute.
I can persist objects of class Test1. However if I try to persist objects of class Test2 I get "java.lang.NoSuchMethodException: Test2.getSomething()"
According to the JavaBeans specification boolean attributes can be accessed either by getXXX or by isXXX. DefaultPersistenceDelegate should support both methods.
EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
DefaultPersistenceDelegate should use the field itself or either method "getSomething" or "isSomething".
ACTUAL -
DefaultPersistenceDelegate uses the field itself or just "getSomething".
---------- BEGIN SOURCE ----------
import java.beans.DefaultPersistenceDelegate;
import java.beans.XMLEncoder;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
public static void main(String[] args) throws IOException {
XMLEncoder e = new XMLEncoder(
new BufferedOutputStream(
new FileOutputStream("Test.xml")));
e.setPersistenceDelegate(Test1.class,
new DefaultPersistenceDelegate(new String[]{"something"}));
e.setPersistenceDelegate(Test2.class, new DefaultPersistenceDelegate(new String[]{"something"}));
e.writeObject(new Test1(true));
e.writeObject(new Test2(true));
e.flush();
e.close();
}
}
public class Test1 {
private boolean something;
public Test1(boolean something) {
this.something = something;
}
public boolean isSomething() {
return something;
}
}
public class Test2 extends Test1 {
public Test2(boolean something) {
super(something);
}
}
---------- END SOURCE ----------
CUSTOMER SUBMITTED WORKAROUND :
If you may modify either Test1 or Test2 then add a method getSomething().
Otherwise create your own PersistenceDelegate that reads all attributes.
(Review ID: 209682)
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