Added git hooks scripts for java formatting

git-hooks/format.sh

@@ -0,0 +1,14 @@
+#!/bin/sh -e
+jar_version=1.6
+jar_dir="$HOME/.local/share/java"
+jar_file="$jar_dir/google-java-format-$jar_version-all-deps.jar"
+java_cmd="java"
+
+# download jar file if missing
+if [ ! -f "$jar_file" ]; then
+    mkdir -p "$jar_dir"
+    wget -O "$jar_file" https://github.com/google/google-java-format/releases/download/google-java-format-$jar_version/google-java-format-$jar_version-all-deps.jar
+fi
+
+# execute formatter
+$java_cmd -jar "$jar_file" $@

git-hooks/pre-commit.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+set -e
+
+echo "Java formatter running..."
+
+format_cmd="$(dirname $(realpath "$0"))/format.sh"
+
+# skip if NO_VERIFY env var set
+if [ "$NO_VERIFY" ]; then
+    echo 'google-java-format skipped' 1>&2
+    exit 0
+fi
+
+# list all added/copied/modified/renamed java files
+git diff --staged --name-only --diff-filter=ACMR | egrep -a '.java$' | tr "\n" "\0" |
+    # run google-java-format on each file and re-stage any new changes
+    xargs -0 -I % echo "$format_cmd --aosp -i '%'; git add -f '%'" | sh

git-hooks/setup.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+if ! git remote get-url origin | grep "lab.si.usi.ch" >/dev/null 2>/dev/null; then
+  echo "Not in the project!"
+  echo "Call this script while in the root directory of the backend project";
+  exit 1;
+elif ! [ -d "./git-hooks" ]; then
+  echo "Not in the right directory!"
+  echo "Call this script while in the root directory of the backend project";
+  exit 1;
+fi;
+
+git config --unset core.hooksPath
+
+this_dir="$(dirname $(realpath "$0"))"
+hook_script="$this_dir/pre-commit.sh"
+ln -svf "$hook_script" "$this_dir/../.git/hooks/pre-commit"
+
+echo "Commit hook installed"