Fix IllegalArgumentException for File properties wich allow null value

[Mingun]

Description

This fix the IllegalArgumentException when TestBean class contains nullable File field (in my case field has name vendorSKPath):

2018-08-02 11:42:54,940 DEBUG o.a.j.t.g.GenericTestBeanCustomizer: Property vendorSKPath has editor class null
2018-08-02 11:42:54,941 DEBUG o.a.j.t.g.WrapperEditor: <-java.lang.String:
2018-08-02 11:42:54,941 DEBUG o.a.j.t.g.WrapperEditor: ->""
2018-08-02 11:42:54,941 DEBUG o.a.j.t.g.GenericTestBeanCustomizer: Property vendorSKPath has property editor org.apache.jmeter.testbeans.gui.FileEditor@1f236f6d
2018-08-02 11:42:54,941 DEBUG o.a.j.t.g.WrapperEditor: <-NULL:null
2018-08-02 11:42:54,941 WARN o.a.j.g.a.Load: Unexpected error. java.lang.IllegalArgumentException
java.lang.IllegalArgumentException: null
	at org.apache.jmeter.testbeans.gui.FieldStringEditor.setValue(FieldStringEditor.java:82) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.WrapperEditor.setValue(WrapperEditor.java:349) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.FileEditor.setValue(FileEditor.java:214) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.GenericTestBeanCustomizer.setEditorValue(GenericTestBeanCustomizer.java:477) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.GenericTestBeanCustomizer.<init>(GenericTestBeanCustomizer.java:289) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.TestBeanGUI.init(TestBeanGUI.java:417) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.testbeans.gui.TestBeanGUI.configure(TestBeanGUI.java:299) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.tree.JMeterTreeModel.addComponent(JMeterTreeModel.java:159) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.tree.JMeterTreeModel.addSubTree(JMeterTreeModel.java:133) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.tree.JMeterTreeModel.addSubTree(JMeterTreeModel.java:133) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.tree.JMeterTreeModel.addSubTree(JMeterTreeModel.java:133) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.tree.JMeterTreeModel.addSubTree(JMeterTreeModel.java:125) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.GuiPackage.addSubTree(GuiPackage.java:522) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.Load.insertLoadedTree(Load.java:193) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.Load.loadProjectFile(Load.java:130) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.Load.loadProjectFile(Load.java:101) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.LoadRecentProject.doActionAfterCheck(LoadRecentProject.java:67) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.AbstractActionWithNoRunningTest.doAction(AbstractActionWithNoRunningTest.java:45) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.ActionRouter.performAction(ActionRouter.java:88) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at org.apache.jmeter.gui.action.ActionRouter.lambda$actionPerformed$0(ActionRouter.java:70) ~[ApacheJMeter_core.jar:4.1-SNAPSHOT.20180802]
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) [?:1.8.0_181]
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) [?:1.8.0_181]
	at java.awt.EventQueue.access$500(EventQueue.java:97) [?:1.8.0_181]
	at java.awt.EventQueue$3.run(EventQueue.java:709) [?:1.8.0_181]
	at java.awt.EventQueue$3.run(EventQueue.java:703) [?:1.8.0_181]
	at java.security.AccessController.doPrivileged(Native Method) [?:1.8.0_181]
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) [?:1.8.0_181]
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) [?:1.8.0_181]
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) [?:1.8.0_181]
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) [?:1.8.0_181]
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) [?:1.8.0_181]
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) [?:1.8.0_181]
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) [?:1.8.0_181]
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) [?:1.8.0_181]

public class WithFile implements TestBean {
    File file;
    public void setFile(File file) { this.file = file; }
    public File getFile() { return file; }
}

public class WithFileBeanInfo extends BeanInfoSupport {
    public WithFileBeanInfo() {
        super(WithFile.class);
        property("file");
    }
}

Motivation and Context

Though in the comment to the class FieldStringEditor it is told that it processes only non-null strings:

jmeter/src/core/org/apache/jmeter/testbeans/gui/FieldStringEditor.java

Lines 29 to 37 in 0a6f36c

	/**
	* This class implements a property editor for non-null String properties that
	* supports custom editing (i.e.: provides a GUI component) based on a text
	* field.
	* <p>
	* The provided GUI is a simple text field.
	*
	*/
	class FieldStringEditor extends PropertyEditorSupport implements ActionListener, FocusListener {

the class WrappedEditor can call setValue with null:

jmeter/src/core/org/apache/jmeter/testbeans/gui/WrapperEditor.java

Lines 332 to 349 in 0a6f36c

	if (value == null) {
	if (!acceptsNull) {
	throw new IllegalArgumentException("Null is not allowed");
	}
	text = null;
	} else if (acceptsExpressions && isExpression(value)) {
	text = (String) value;
	} else {
	// Not an expression (isn't or can't be), not null.
	typeEditor.setValue(value); // may throw IllegalArgumentExc.
	text = fixGetAsTextBug(typeEditor.getAsText());
	if (!acceptsOther && !isATag(text)) {
	throw new IllegalArgumentException("Value not allowed: '" + text + "' is not in " + Arrays.toString(getTags()));
	}
	}
	guiEditor.setValue(text);

So I think that comment also need to be updated, but I am not sure. It is possible that this class as envisioned shall not allow null and it is necessary to do fix in other place, but in case of my testing this fix works fine.

How Has This Been Tested?

Create plugin with any TestBean class with nullable File field as show above

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.

[Mingun]

Any news?

[FSchumacher]

Thanks for your contribution and the detailed description.
Is there any reason, that you don't want to specify a default value for a property that can be undefined? Look for example at Example3BeanInfo.java.
Other than that it seems OK to include the patch, as there is a code path into FieldStringEditor that would allow null values.

[Mingun]

In my plugin it is filepath that enable optional feature, so when it is undefined the feature is off.

In the next 2 weeks I will not be able to work on PR since I am on vacation, therefore if any additional work are required, then be not surprised that I will answer not soon.

[Mingun]

Now its ready to merge. Travis fail is unrelated to this changes

[FSchumacher]

I have modified your code slightly where I think it helps readability. It should contain no functional difference to your code. It would be nice, if you could test the next nightly or current trunk.

Thanks again for your contribution.

[Mingun]

Thanks!

I was tested with 2c82bf3 (trunk branch). The exception does not arise any more though to set Undefined value for File property is impossible now, even though the flag {{NOT_UNDEFINED}} is not set for property. I attach 2 screenshots showing behavior of the same plugin file in versions 3.1 and 5.1:

Therefore this fix so far not really helps me

[FSchumacher]

OK, so we really have to explicitly allow null to help you there, right? Does the last change help you?

[Mingun]

Does the last change help you?

No. Actually, the problem isn't connected with this task any more, the editor has changed as a result of the сommit fc4781d which is linked to bug 61625, at first sight absolutely not relating to it

After reverting this change editor look as I expect:

@pmouawad, can you look at this? Change that you made is necessary? What strange behavior that you talk about? In my opinion, combobox works as expected and I don't represent at all how it can influence perfomance