| // Copyright 2016 The Bazel Authors. All Rights Reserved. |
| // |
| // 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. |
| |
| package com.google.testing.junit.runner.junit4; |
| |
| import com.google.testing.junit.runner.util.Factory; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.function.Supplier; |
| |
| /** |
| * A factory that supplies {@link OutputStream}. |
| */ |
| public final class ProvideXmlStreamFactory implements Factory<OutputStream> { |
| private final Supplier<JUnit4Config> configSupplier; |
| |
| public ProvideXmlStreamFactory(Supplier<JUnit4Config> configSupplier) { |
| if (configSupplier == null) { |
| throw new IllegalStateException(); |
| } |
| |
| this.configSupplier = configSupplier; |
| } |
| |
| @Override |
| public OutputStream get() { |
| return new LazyOutputStream(() -> JUnit4RunnerModule.provideXmlStream(configSupplier.get())); |
| } |
| |
| public static Factory<OutputStream> create(Supplier<JUnit4Config> configSupplier) { |
| return new ProvideXmlStreamFactory(configSupplier); |
| } |
| |
| private static class LazyOutputStream extends OutputStream { |
| private Supplier<OutputStream> supplier; |
| private volatile OutputStream delegate; |
| |
| public LazyOutputStream(Supplier<OutputStream> supplier) { |
| this.supplier = supplier; |
| } |
| |
| private OutputStream ensureDelegate() { |
| OutputStream delegate0 = delegate; |
| if (delegate0 != null) { |
| return delegate0; |
| } |
| |
| synchronized (this) { |
| if (delegate == null) { |
| delegate = supplier.get(); |
| supplier = null; |
| } |
| } |
| |
| return delegate; |
| } |
| |
| @Override |
| public void write(int b) throws IOException { |
| ensureDelegate().write(b); |
| } |
| |
| @Override |
| public void write(byte[] b, int off, int len) throws IOException { |
| ensureDelegate().write(b, off, len); |
| } |
| |
| @Override |
| public void write(byte[] b) throws IOException { |
| ensureDelegate().write(b); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (delegate != null) { |
| delegate.close(); |
| } |
| } |
| |
| @Override |
| public void flush() throws IOException { |
| if (delegate != null) { |
| delegate.flush(); |
| } |
| } |
| } |
| } |