[build] Remove cmake Java support (#8952)

This is increasingly difficult to maintain, and has very limited
benefit. Modern coprocessors with enough horsepower to run Java
applications can use the Gradle or Bazel build systems instead.

wpimath/CMakeLists.txt

@@ -3,7 +3,6 @@ project(wpimath)
 include(SubDirList)
 include(CompileWarnings)
 include(AddTest)
-include(DownloadAndCheck)
 
 file(
     GLOB wpimath_jni_src
@@ -21,104 +20,6 @@ file(
     src/main/native/cpp/jni/optimization/ProblemJNI.cpp
 )
 
-# Java bindings
-if(WITH_JAVA)
-    include(UseJava)
-
-    if(NOT EXISTS "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml/ejml-simple-0.44.0.jar")
-        set(BASE_URL "https://search.maven.org/remotecontent?filepath=")
-        set(JAR_ROOT "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml")
-
-        message(STATUS "Downloading EJML jarfiles...")
-
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-cdense/0.44.0/ejml-cdense-0.44.0.jar"
-            "${JAR_ROOT}/ejml-cdense-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-core/0.44.0/ejml-core-0.44.0.jar"
-            "${JAR_ROOT}/ejml-core-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-ddense/0.44.0/ejml-ddense-0.44.0.jar"
-            "${JAR_ROOT}/ejml-ddense-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-dsparse/0.44.0/ejml-dsparse-0.44.0.jar"
-            "${JAR_ROOT}/ejml-dsparse-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-fdense/0.44.0/ejml-fdense-0.44.0.jar"
-            "${JAR_ROOT}/ejml-fdense-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-simple/0.44.0/ejml-simple-0.44.0.jar"
-            "${JAR_ROOT}/ejml-simple-0.44.0.jar"
-        )
-        download_and_check(
-            "${BASE_URL}org/ejml/ejml-zdense/0.44.0/ejml-zdense-0.44.0.jar"
-            "${JAR_ROOT}/ejml-zdense-0.44.0.jar"
-        )
-
-        message(STATUS "All files downloaded.")
-    endif()
-
-    file(GLOB EJML_JARS "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml/*.jar")
-    file(GLOB AVAJE_JARS "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/avaje/*.jar")
-    file(GLOB QUICKBUF_JAR ${WPILIB_BINARY_DIR}/wpiutil/thirdparty/quickbuf/*.jar)
-
-    set(CMAKE_JNI_TARGET true)
-
-    file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java src/generated/main/java/*.java)
-
-    add_jar(
-        wpimath_jar
-        ${JAVA_SOURCES}
-        INCLUDE_JARS
-            wpiutil_jar
-            wpiunits_jar
-            wpiannotations_jar
-            ${EJML_JARS}
-            ${AVAJE_JARS}
-            ${QUICKBUF_JAR}
-        OUTPUT_NAME wpimath
-        OUTPUT_DIR ${WPILIB_BINARY_DIR}/${java_lib_dest}
-        GENERATE_NATIVE_HEADERS wpimath_jni_headers
-    )
-    set_property(TARGET wpimath_jar PROPERTY FOLDER "java")
-
-    install_jar(wpimath_jar DESTINATION ${java_lib_dest})
-    install_jar_exports(TARGETS wpimath_jar FILE wpimath_jar.cmake DESTINATION share/wpimath)
-
-    add_library(wpimathjni ${wpimath_jni_src})
-    wpilib_target_warnings(wpimathjni)
-    target_link_libraries(wpimathjni PUBLIC wpimath)
-
-    set_property(TARGET wpimathjni PROPERTY FOLDER "libraries")
-
-    target_link_libraries(wpimathjni PRIVATE wpimath_jni_headers)
-    add_dependencies(wpimathjni wpimath_jar)
-
-    install(TARGETS wpimathjni EXPORT wpimathjni)
-    export(TARGETS wpimathjni FILE wpimathjni.cmake NAMESPACE wpimathjni::)
-endif()
-
-if(WITH_JAVA_SOURCE)
-    include(UseJava)
-    include(CreateSourceJar)
-    add_source_jar(
-        wpimath_src_jar
-        BASE_DIRECTORIES
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/main/java
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/generated/main/java
-        OUTPUT_NAME wpimath-sources
-        OUTPUT_DIR ${WPILIB_BINARY_DIR}/${java_lib_dest}
-    )
-    set_property(TARGET wpimath_src_jar PROPERTY FOLDER "java")
-
-    install_jar(wpimath_src_jar DESTINATION ${java_lib_dest})
-endif()
-
 file(
     GLOB_RECURSE wpimath_native_src
     src/main/native/cpp/*.cpp

wpimath/wpimath-config.cmake.in

@@ -8,8 +8,3 @@ endif()
 
 @FILENAME_DEP_REPLACE@
 include(${SELF_DIR}/wpimath.cmake)
-if(@WITH_JAVA@)
-    @WPIUNITS_DEP_REPLACE@
-    @FILENAME_DEP_REPLACE@
-    include(${SELF_DIR}/wpimath_jar.cmake)
-endif()