Formatting exception message #16
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| final Class<?> clazz = defineClass(transformedName, transformedClass, 0, transformedClass.length, codeSource); | ||
| cachedClasses.put(transformedName, clazz); | ||
| return clazz; | ||
| if (transformedClass != null) { |
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Honestly I don't think there is anything wrong with skipping the null check here. If it is null then it throws an exception which is caught and logged below. Thus adding more detail to the stack trace. More details, the better. So I don't see a need for this protection.
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IMO it is worth checking it, as otherwise it will NPE when trying to save the transformed class (DEBUG_SAVE == true), and when not debug saving, the exception it does print points to the classloader itself NPEing, not that it couldn't find the class source.
There's also zero point going through the transformer list with null bytes, unless you're expecting one of them might provide the data?!
| if (DEBUG) { | ||
| LogWrapper.log(Level.TRACE, e, "Exception encountered attempting classloading of %s", name); | ||
| LogManager.getLogger("LaunchWrapper").log(Level.ERROR, "Exception encountered attempting classloading of %s", e); | ||
| LogManager.getLogger("LaunchWrapper").log(Level.ERROR, String.format("Exception encountered attempting classloading of %s", name), e); |
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This however, is fine, cuz derp.
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Why not use the proper log4j way of doing things - basically replace %s for {}, no String#format(String) needed.
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@jamierocks There does not appear to be an interface method that takes both a Throwable and params.
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I believe that log4j knows to use the last parameter as a Throwable when taking a series of other parameters; however, I cannot find a source.
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I would write it this way:
LogManager.getLogger("LaunchWrapper").error("Exception encountered attempting classloading of {}", name, e);Internally the logger creates a FormattedMessage which can take a Throwable as the last argument:
https://logging.apache.org/log4j/log4j-2.1/log4j-api/apidocs/org/apache/logging/log4j/message/FormattedMessage.html
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Tracing through it doesn't use that constructor from the varargs method, but it does appear poke was correct as it seems to scan it at org.apache.logging.log4j.message.ParameterizedMessage#parseArguments
Chaarlesss
changed the title
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Why, why this isn't merged? |
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I just fix two bugs I found during my experiments