Hi Sergey, The below marked stack trace would be hit if there is any exception raised while creating the Error object in the try block. But the user would still get the stack trace if the exception is not handled because the Error calls base class function of Throwable:
public Throwable(String message) {
fillInStackTrace();
detailMessage = message;
}
The stack trace would be printed by the above code in Throwable implementation.
I believe it is inevitable to print this because this is one of the basic level
implementation and we do have an unhandled exception. And I don't think I
should do any change in here. Please let me know if you think otherwise.
I have attached the test file which I used to test the user level effects. The
user won't be able to use the expressions like this (if(UIManager.getUI(comp)
== null)) as mentioned in the JIRA bug but he will be able to use the below
catching code:
try {
System.out.println("Updating UI");
UIManager.getUI(comp);
} catch (Exception e) {
System.out.println("GetUI is null");
System.out.println(e.getMessage());
}
The output of this is as follows:
Updating UI
GetUI is null
Null
If the there is no exception catch performed then it would have the below
output:
LAF State: [Custom LAF - CustomUI$1],LAF Class:
com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Exception in thread "main" java.lang.NullPointerException
at
java.desktop/javax.swing.MultiUIDefaults.getUIError(MultiUIDefaults.java:131)
at java.desktop/javax.swing.UIDefaults.getUI(UIDefaults.java:790)
at java.desktop/javax.swing.UIManager.getUI(UIManager.java:1065)
at CustomUI.main(CustomUI.java:50)
Process finished with exit code 1
Please let me know if any part of my analysis is wrong or skewed.
Thanks and regards,
Shashi
-----Original Message-----
From: Sergey Bylokhov
Sent: Saturday, June 17, 2017 1:22 AM
Cc: Shashidhara Veerabhadraiah <shashidhara.veerabhadra...@oracle.com>;
swing-dev <swing-dev@openjdk.java.net>; Philip Race <philip.r...@oracle.com>;
Semyon Sadetsky <semyon.sadet...@oracle.com>
Subject: Re: <Swing Dev> [10] RFR JDK-6267105:UIDefaults.getUIError dumps error
message to System.err and also throws Error.
Hi, Shashi.
Can you please clarify the purpose of this fix, because the bug states that the
code prints traceback to the system.err, even if the user tries to
catch/suppress an exception.
The current fix removed the system.err logging but the code which print trace
still there:
protected void getUIError(String msg) {
try {
throw new Error(msg);
}
catch (Throwable e) {
e.printStackTrace();
}
}
>> Through catching the error, the user can perform necessary recovery actions
>> without cluttering the system.err
I am not sure that the user is able to catch this error. So what is the
difference when we had an additional message before and after the fix?
>
> +1
>
> --Semyon
>
>
> On 06/12/2017 03:54 AM, Shashidhara Veerabhadraiah wrote:
>> Hi All,
>> Please review the code bug fix for
>> JDK-6267105:UIDefaults.getUIError dumps error message to System.err and also
>> throws Error.
>>
>> Issue:
>> Error message was getting dumped to the system.err even though the
>> recovery actions were performed leading to unnecessary confusion regarding
>> the actual behavior.
>>
>> Fix:
>> This fix removes the call which prints the message to the system.err and
>> stores the message in the Error class. This same message can be retrieved
>> after we catch the error and calling getMessage() of the Error class.
>> Through catching the error, the user can perform necessary recovery actions
>> without cluttering the system.err. This fix does not modifies the 'user
>> effect' as the user would still get the same error as they were getting
>> before this fix.
>>
>> Test:
>> Now the system.err does not get cluttered though we performed the
>> necessary recovery actions. The error message string can be recovered by
>> calling getMessage() if needed.
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-6267105
>>
>> Webrev:
>> http://cr.openjdk.java.net/~aghaisas/shashi/6267105/webrev_00/
>>
>> Thanks and regards,
>> Shashi
>
CustomUI.JAVA
Description: Binary data
