Ubuntu编译TinyB时CMake提示无法找到javah工具，求助解决方案

Got it, this error pops up because javah was deprecated in JDK 9 and fully removed in later Java versions, but TinyB's Java CMake script still relies on this old tool. Let's fix this with one of two straightforward approaches:

1. Update TinyB's CMake Script to Use Modern javac (Recommended) #

Since you're building from source, modifying the Java CMake file is the cleanest long-term fix:

• Open java/CMakeLists.txt in your TinyB source directory (the file referenced in your error).
• Find the section where javah is being searched for and executed (around line 16).
• Replace the javah references with javac using its -h flag—this flag does the same job javah used to do: generating JNI headers.

For example, if the original code looks like this:

find_program(JAVAH_EXECUTABLE javah REQUIRED)
add_custom_command(
    OUTPUT ${JNI_HEADERS}
    COMMAND ${JAVAH_EXECUTABLE} -jni -d ${CMAKE_CURRENT_BINARY_DIR} -classpath ${CLASSPATH} ${JAVA_CLASSES}
    DEPENDS ${JAVA_SOURCES}
)

Change it to:

find_program(JAVAC_EXECUTABLE javac REQUIRED)
add_custom_command(
    OUTPUT ${JNI_HEADERS}
    COMMAND ${JAVAC_EXECUTABLE} -h ${CMAKE_CURRENT_BINARY_DIR} -classpath ${CLASSPATH} ${JAVA_SOURCES}
    DEPENDS ${JAVA_SOURCES}
)

2. Fall Back to JDK 8 (No Source Modifications Needed) #

If you'd rather not tweak the code, install JDK 8 (which still includes javah) and point CMake to it:

• Install OpenJDK 8 on Ubuntu:

  sudo apt update && sudo apt install openjdk-8-jdk
  

• Clear any existing CMake cache to avoid conflicts:

  rm -rf CMakeFiles CMakeCache.txt
  

• Run CMake with the JDK 8 path (adjust the path if your JDK is installed in a different location):

  cmake -DBUILDJAVA=ON -DJAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
  

Wrap-Up #

After applying either fix, re-run your CMake command and continue the build:

cmake -DBUILDJAVA=ON
make
sudo make install

内容的提问来源于stack exchange，提问作者Black Boy