Name: vrR10176 Date: 05/29/2001



Api spec (jdk1.4.0beta-b65) says about method
javax.imageio.plugins.jpeg.JPEGImageWriteParam.isCompressionLossless():
"public boolean isCompressionLossless()
     Description copied from class: ImageWriteParam
     Returns true if the current compression type provides lossless compression. If a plug-in
     provides only one mandatory compression type, then this method may be called without
     calling setCompressionType first.
...
     Throws:
...
         IllegalStateException - if the compression mode is not MODE_EXPLICIT.
..."

But the method does not throw IllegalStateException when the compression mode is not MODE_EXPLICIT.
The default JPEGImageWriteParam compression mode is MODE_COPY_FROM_METADATA.

This bug causes failure of new JCK test:
api/javax_imageio/plugins/jpeg/JPEGImageWriteParam/index.html#isCompressionLossless

To reproduce the issue execute following test.
------------------------ test.java ------------------------
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;

public class test {

    public static void main(String[] argv) {

        JPEGImageWriteParam imagewriteparam = new JPEGImageWriteParam(null);

        try {
            System.out.println("compression mode is not MODE_EXPLICIT");
            System.out.println("getCompressionMode() returns " + imagewriteparam.getCompressionMode() +
                               ", not " + JPEGImageWriteParam.MODE_EXPLICIT);
            imagewriteparam.isCompressionLossless();
            System.out.println("Test failed. IllegalStateException was expected");
        } catch (IllegalStateException e) {
            System.out.println("Test passed");
        }
    }
}
------------ Logs ------------------------------------------
$ java -version
java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b65)
Java HotSpot(TM) Client VM (build 1.4.0-beta-b65, mixed mode)

$ javac test.java

$ java test
compression mode is not MODE_EXPLICIT
getCompressionMode() returns 3, not 2
Test failed. IllegalStateException was expected

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