Java support fails to build: error: annotations are not supported in -source 1.4

[Bas Couwenberg]

GDAL 2.1.0-beta1 fails to build due to an error building the Java bindings:

compile:
    [mkdir] Created dir: /build/gdal-2.1.0~beta1+dfsg/swig/java/build/classes
    [javac] Compiling 62 source files to /build/gdal-2.1.0~beta1+dfsg/swig/java/build/classes
    [javac] warning: [options] bootstrap class path not set in conjunction with -source 1.4
    [javac] warning: [options] source value 1.4 is obsolete and will be removed in a future release
    [javac] warning: [options] target value 1.4 is obsolete and will be removed in a future release
    [javac] warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_GIntBig.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_GIntBig(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                            ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_OGRErr.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_OGRErr(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                           ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_OGRFeatureShadow.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_OGRFeatureShadow(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                                     ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_OGRLayerShadow.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_OGRLayerShadow(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                                   ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_OGRwkbGeometryType.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_OGRwkbGeometryType(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                                       ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_OSRSpatialReferenceShadow.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_OSRSpatialReferenceShadow(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                                              ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] /build/gdal-2.1.0~beta1+dfsg/swig/java/org/gdal/gnm/SWIGTYPE_p_p_char.java:14: error: annotations are not supported in -source 1.4
    [javac]   protected SWIGTYPE_p_p_char(long cPtr, @SuppressWarnings("unused") boolean futureUse) {
    [javac]                                           ^
    [javac]   (use -source 5 or higher to enable annotations)
    [javac] 7 errors
    [javac] 4 warnings

With the deprecation of Java 7, I think it's a good idea to bump the source and target versions in swig/java/build.xml to 1.8. At least 1.5 should be used for annotations.

[Even Rouault]

I guess the annotations are put by the SWIG version you are using. Which one is it ? I don't get them with my ancient SWIG. But probably bumping to 1.5 could be appropriate indeed !

[Bas Couwenberg]

The Debian package build uses SWIG 3.0.7 from Debian unstable.

The attached patch updates the source and target version to 1.5 which allows the build to succeed.

[Even Rouault]

trunk r33866 "Java bindings: bump minimal java version to 1.5 in case SWIG generates anotations (#6433, patch by Bas Couwenberg)"

Although the fundamental problem raised by the warnings is #6434, and thus the aboe commit r33866 isn't strictly needed after r33867