Java tutorial
/* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.impl.client.cache; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import org.apache.http.annotation.Immutable; import org.apache.http.client.cache.InputLimit; import org.apache.http.client.cache.Resource; import org.apache.http.client.cache.ResourceFactory; /** * Generates {@link Resource} instances stored entirely in heap. * * @since 4.1 */ @Immutable public class HeapResourceFactory implements ResourceFactory { public Resource generate(final String requestId, final InputStream instream, final InputLimit limit) throws IOException { ByteArrayOutputStream outstream = new ByteArrayOutputStream(); byte[] buf = new byte[2048]; long total = 0; int l; while ((l = instream.read(buf)) != -1) { outstream.write(buf, 0, l); total += l; if (limit != null && total > limit.getValue()) { limit.reached(); break; } } return new HeapResource(outstream.toByteArray()); } public Resource copy(final String requestId, final Resource resource) throws IOException { byte[] body; if (resource instanceof HeapResource) { body = ((HeapResource) resource).getByteArray(); } else { ByteArrayOutputStream outstream = new ByteArrayOutputStream(); IOUtils.copyAndClose(resource.getInputStream(), outstream); body = outstream.toByteArray(); } return new HeapResource(body); } }