Hi,
We are using Apache FOP 0.95 to produce TIFF images in CCITT T.6 format in a
j2ee application(thus this is a multithreaded environment). We also use FOP
0.95 to produce pdf images in the same application with the same inputs. A
while back we had an issue where producing the tiff images resulted in
extreme overlapping in the images(In some cases the application produced
blank images). Upon initial observation it was observed that the
transformation that results in the tiff images is not thread safe, while the
one producing the pdf images is. To test this hypothesis, we have produced
the test case named Test_FopTiffTransformMultithreaded.java(attached). This
test case provides proof of concept that the tiff image conversion is not
thread safe. A few notes on the test case:
1) The following jars would be needed in the class path:
-commons-io-1.3.1.jar
-fop-0.95.jar
-xml-apis-ext-1.3.04.jar
-xmlgraphics-commons-1.3.1.jar
-spring-2.0.5.jar
-junit-3.8.1.jar
-jdom.jar
-saxpath.jar
-commons-logging-1.04.jar
-avalon-framework-4.2.0.jar
2) The properties(static strings) in the test case translate as follows:
EXPECTED_THREAD_COUNT -> the expected number of threads we want to test
with(value 1 to N)
OUTPUT_FILE_DIRECTORY_PATH -> The file path to the directory where the
images are stored
OUTPUT_FILE_NAME -> The name of the file that will be output(for example if
this value is "image", and the thread count is 2, then the output files will
be named as "image0", "image1")
OUTPUT_FILE_FORMAT -> this value is expected to be either ".pdf" or ".tiff"
OUTPUT_FILE_FORMAT_TYPE -> this value is expected to be either "pdf" or
"tiff" and must match the file format in the OUTPUT_FILE_FORMAT above
PRINTABLE_FO_PATH -> the file path to the xsl transformation file
3) The xml file which will be rendered(named "InputFile.xml") in this test
case should be placed in the same directory as the test case.
4) Line 181 of this test case shows the following:
// synchronized (fopFactory)
// {
transformer.transform(src, result);
// }
This indicates a synchronization of the fopFactory object. If this
synchronization block is not present and the output is in tiff images, the
text in the images is overlapped. If this synchronization block is present,
there are SEVERE performance implications on our application as this
synchronization introduces performance issues(I can provide the performance
differential if needed). An example of the correct image(imageCorrect.tiff)
is attached and the overlapped image as a result of the multithreaded
process(EXPECTED_THREAD_COUNT >1) without
synchronization(imageIncorrect.tiff) is also attached.
I am attaching all the files(except the jars) that are needed for this test
case.
The following is my question. How can this tiff image problem be corrected?
As we are working with highly demanding customers(as everyone is :-):-)
http://old.nabble.com/file/p27567366/Test_FopTiffTransformMultithreaded.java
Test_FopTiffTransformMultithreaded.java
http://old.nabble.com/file/p27567366/InputFile.xml InputFile.xml
http://old.nabble.com/file/p27567366/Transformer.xsl Transformer.xsl
http://old.nabble.com/file/p27567366/imageCorrect.tiff imageCorrect.tiff
http://old.nabble.com/file/p27567366/imageIncorrect.tiff imageIncorrect.tiff
), we need to solve the performance problems as well as the tiff image
issue. We would be really grateful if this issue can be solved.
Thanks
Hasan
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