install:
- java 7 or later
- maven 3.3 or later
git submodule update --init --recursive # Needed for flight
cd java
mvn install
Arrow Cpp must be built before this step. The cpp build directory must be provided as the value for argument arrow.cpp.build.dir. eg.
cd java
mvn install -P arrow-jni -am -Darrow.cpp.build.dir=../../release
The gandiva library is still in Alpha stages, and subject to API changes without deprecation warnings.
Arrow uses Google's Flatbuffers to transport metadata. The java version of the library requires the generated flatbuffer classes can only be used with the same version that generated them. Arrow packages a verion of the arrow-vector module that shades flatbuffers and arrow-format into a single JAR. Using the classifier "shade-format-flatbuffers" in your pom.xml will make use of this JAR, you can then exclude/resolve the original dependency to a version of your choosing.
Arrow Java follows the Google style guide here with the following differences:
- Imports are grouped, from top to bottom, in this order: static imports, standard Java, org.*, com.*
- Line length can be up to 120 characters
- Operators for line wrapping are at end-of-line
- Naming rules for methods, parameters, etc. have been relaxed
- Disabled
NoFinalizer,OverloadMethodsDeclarationOrder, andVariableDeclarationUsageDistancedue to the existing code base. These rules should be followed when possible.
Refer to `java/dev/checkstyle/checkstyle.xml for rule specifics.
When running tests, Arrow Java uses the Logback logger with SLF4J. By default, it uses the logback.xml present in the corresponding module's src/test/resources directory, which has the default log level set to INFO. Arrow Java can be built with an alternate logback configuration file using the following command run in the project root directory:
mvn -Dlogback.configurationFile=file:<path-of-logback-file>See Logback Configuration for more details.