fix warning and info by shfmt

Author: kiszk

ci/scripts/java_build.sh

@@ -22,16 +22,15 @@ if [[ "${ARROW_JAVA_BUILD:-ON}" != "ON" ]]; then
   exit
 fi
 
-arrow_dir=${1}
 source_dir=${1}
 build_dir=${2}
 java_jni_dist_dir=${3}
 
-: ${BUILD_DOCS_JAVA:=OFF}
+: "${BUILD_DOCS_JAVA:=OFF}"
 
 mvn="mvn -B -DskipTests -Drat.skip=true -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn"
 
-if [ $ARROW_JAVA_SKIP_GIT_PLUGIN ]; then
+if [ "$ARROW_JAVA_SKIP_GIT_PLUGIN" ]; then
   mvn="${mvn} -Dmaven.gitcommitid.skip=true"
 fi
 
@@ -79,9 +78,9 @@ ${mvn} -T 2C clean install
 if [ "${BUILD_DOCS_JAVA}" == "ON" ]; then
   # HTTP pooling is turned of to avoid download issues https://issues.apache.org/jira/browse/ARROW-11633
   # GH-43378: Maven site plugins not compatible with multithreading
-  mkdir -p ${build_dir}/docs/java/reference
+  mkdir -p "${build_dir}"/docs/java/reference
   ${mvn} -Dcheckstyle.skip=true -Dhttp.keepAlive=false -Dmaven.wagon.http.pool=false clean install site
-  rsync -a target/site/apidocs/ ${build_dir}/docs/java/reference
+  rsync -a target/site/apidocs/ "${build_dir}"/docs/java/reference
 fi
 
 popd

ci/scripts/java_test.sh

@@ -22,7 +22,6 @@ if [[ "${ARROW_JAVA_TEST:-ON}" != "ON" ]]; then
   exit
 fi
 
-arrow_dir=${1}
 source_dir=${1}
 build_dir=${2}
 java_jni_dist_dir=${3}
@@ -31,7 +30,7 @@ mvn="mvn -B -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMave
 # Use `2 * ncores` threads
 mvn="${mvn} -T 2C"
 
-pushd ${build_dir}
+pushd "${build_dir}"
 
 ${mvn} -Darrow.test.dataRoot="${source_dir}/testing/data" clean test
 
@@ -44,12 +43,12 @@ fi
 if [ "${#projects[@]}" -gt 0 ]; then
   ${mvn} clean test \
          -Parrow-jni \
-         -pl $(IFS=,; echo "${projects[*]}") \
-         -Darrow.cpp.build.dir=${java_jni_dist_dir}
+         -pl "$(IFS=,; echo \"${projects[*]}\")" \
+         -Darrow.cpp.build.dir="${java_jni_dist_dir}"
 fi
 
 if [ "${ARROW_JAVA_CDATA}" = "ON" ]; then
-  ${mvn} clean test -Parrow-c-data -pl c -Darrow.c.jni.dist.dir=${java_jni_dist_dir}
+  ${mvn} clean test -Parrow-c-data -pl c -Darrow.c.jni.dist.dir="${java_jni_dist_dir}"
 fi
 
 popd