Sample Java buildpack configuration override. NB. this is not supported by the Java buildpack - it is only a proposal.

openjdk.yml

# Cloud Foundry Java Buildpack
# Copyright (c) 2013 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Configuration for JRE repositories keyed by vendor
---
repository_root: "http://download.pivotal.io.s3.amazonaws.com/openjdk/lucid/x86_64"
version: 1.6.+
memory_heuristics:
  post_8:
    heap: 0.75
    metaspace: 0.1
    stack: 0.05
    native: 0.1
  pre_8:
    heap: 0.75
    permgen: 0.1
    stack: 0.05
    native: 0.1

tomcat.yml

# Cloud Foundry Java Buildpack
# Copyright (c) 2013 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Configuration for Tomcat
---
version: 6.+
repository_root: "http://download.pivotal.io.s3.amazonaws.com/tomcat/lucid/x86_64"