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  1. JDK
  2. JDK-4950122

LTP: DefaultPersistenceDelegate does not handle boolean properties in a superclass.

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    • Subcomponent:
    • Introduced In Build:
      b76
    • Introduced In Version:
      6
    • Resolved In Build:
      b07
    • CPU:
      generic, x86
    • OS:
      linux, solaris_nevada, windows_2000, windows_xp
    • Verification:
      Verified

      Backports

        Description

        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)
        ======================================================================

        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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                Assignee:
                malenkov Sergey Malenkov (Inactive)
                Reporter:
                jleesunw Jon Lee (Inactive)
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