[BEANUTILS-541] FluentPropertyBeanIntrospector caches corrupted writeMethod (two subclasses)

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.9.0, 1.9.1, 1.9.2, 1.9.3, 1.9.4
• Fix Version/s: 2.0.0, 1.9.5
• Component/s: Bean / Property Utils
• Assignee: Unassigned
• Reporter: Sergey Chernov
• Created: 02/Nov/20 13:27
• Updated: 14/Apr/24 20:27
• Resolved: 14/Apr/24 12:48

Description

There is an issue in FluentPropertyBeanIntrospector (at line 144 for 1.9.3), it caches wrong writeMethod in the static cache of java.beans.Introspector when base class (with chained setter) has at least two subclasses. Simple snippet to reproduce:

import org.apache.commons.beanutils.FluentPropertyBeanIntrospector;
import org.apache.commons.beanutils.PropertyUtilsBean;

public class BeanUtilsTest {

    public static void main(String[] args) throws Exception {
        PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
        propertyUtilsBean.addBeanIntrospector(new FluentPropertyBeanIntrospector());

        // invert if condition and it will succeed
        if (true) {
            // fails

            SubTypeA subTypeA = new SubTypeA();
            //subTypeA.setField("name");
            propertyUtilsBean.setProperty(subTypeA, "field", "name");

            // uncomment this line and the failure will be handled (workaround)
            //java.beans.Introspector.flushCaches();

            SubTypeB subTypeB = new SubTypeB();
            //subTypeB.setField("name");
            propertyUtilsBean.setProperty(subTypeB, "field", "name");
        } else {
            // the same as above, but reverse order - success

            SubTypeB subTypeB = new SubTypeB();
            //subTypeB.setField("name");
            propertyUtilsBean.setProperty(subTypeB, "field", "name");

            SubTypeA subTypeA = new SubTypeA();
            //subTypeA.setField("name");
            propertyUtilsBean.setProperty(subTypeA, "field", "name");
        }
    }

    public static class BaseType {

        private String field;

        public BaseType setField(String objectName) {
            this.field = objectName;
            // pay attention - setter returns self object (not void)
            return this;
        }

        public String getField() {
            return field;
        }
    }

    public static class SubTypeA extends BaseType {

        @Override
        public SubTypeA setField(String field) {
            super.setField(field);
            return this;
        }
    }

    public static class SubTypeB extends BaseType {

    }
}

 
It is critical, because wrong information is stored globally unless explicit Introspector.flushCaches (Introspector.flushFromCaches) is called.

Failure stacktrace:

Exception in thread "main" java.lang.IllegalArgumentException: org.jeasy.random.BeanUtilsTest$SubTypeB is not assignable from org.jeasy.random.BeanUtilsTest$SubTypeA
	at org.apache.commons.beanutils.MethodUtils.getAccessibleMethod(MethodUtils.java:793)
	at org.apache.commons.beanutils.PropertyUtilsBean.getWriteMethod(PropertyUtilsBean.java:1319)
	at org.apache.commons.beanutils.PropertyUtilsBean.setSimpleProperty(PropertyUtilsBean.java:2094)
	at org.apache.commons.beanutils.PropertyUtilsBean.setNestedProperty(PropertyUtilsBean.java:1915)
	at org.apache.commons.beanutils.PropertyUtilsBean.setProperty(PropertyUtilsBean.java:2022)
	at org.jeasy.random.BeanUtilsTest.main(BeanUtilsTest.java:44)

Issue Links

• is caused by: BEANUTILS-428 Provide a BeanIntrospector implementation which supports properties in a fluent API
• links to: GitHub Pull Request #68
• links to: GitHub Pull Request #69
• links to: GitHub Pull Request #234