Getting the code

git clone https://github.com/houglum/maven-multimodule-google-cloud-java
cd maven-multimodule-google-cloud-java
git submodule update --init --recursive

Building/Running

Setting up credentials

The main module uses Google Application Default Credentials. If you have a JSON keyfile, run this command so that the program knows where to find your keyfile:

export GOOGLE_APPLICATION_CREDENTIALS="/path/to/keyfile.json"

If you're using a GCE service account, make sure that it has been granted an IAM role that grants the iam.serviceAccounts.signBlob permission.

Providing your resource names and building/running

BKT_NAME="your-bucket-name-here"
GET_OBJ_NAME="name-of-an-object-in-your-bucket-that-already-exists"
PUT_OBJ_NAME="name-of-an-object-you-want-to-create"

mvn install -DskipTests && \
mvn exec:java --projects main-module \
    -Dexec.args="${BKT_NAME:?must be set} ${GET_OBJ_NAME:?must be set} ${PUT_OBJ_NAME:?must be set}"


# NOTE: If you'd like to re-build the project after altering the main module, it
# is much faster to only recompile that module. This can be accomplished using
# maven's `--projects` flag, as shown below:

mvn install --projects main-module -DskipTests && \
mvn exec:java --projects main-module \
    -Dexec.args="${BKT_NAME:?must be set} ${GET_OBJ_NAME:?must be set} ${PUT_OBJ_NAME:?must be set}"

# Similarly, if you edit both the google-cloud-storage and main-module projects,
# you can specify that the `install` step should only rebuild those:
mvn install \
    --projects main-module,google-cloud-java/google-cloud-clients/google-cloud-storage \
    -DskipTests