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Diffstat (limited to 'simple/simple-http/src/main/java/org/simpleframework/http/message/FixedLengthConsumer.java')
-rw-r--r-- | simple/simple-http/src/main/java/org/simpleframework/http/message/FixedLengthConsumer.java | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/simple/simple-http/src/main/java/org/simpleframework/http/message/FixedLengthConsumer.java b/simple/simple-http/src/main/java/org/simpleframework/http/message/FixedLengthConsumer.java new file mode 100644 index 0000000..5358d4b --- /dev/null +++ b/simple/simple-http/src/main/java/org/simpleframework/http/message/FixedLengthConsumer.java @@ -0,0 +1,128 @@ +/* + * FixedLengthConsumer.java February 2007 + * + * Copyright (C) 2001, Niall Gallagher <niallg@users.sf.net> + * + * 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 org.simpleframework.http.message; + +import java.io.IOException; + +import org.simpleframework.common.buffer.Allocator; +import org.simpleframework.common.buffer.Buffer; + +/** + * The <code>FixedLengthConsumer</code> object reads a fixed number of + * bytes from a cursor. This is typically used when the Content-Length + * header is used as the body delimiter. In order to determine when + * the full body has been consumed this counts the bytes read. Once + * all the bytes have been read any overflow will be reset. All of the + * bytes read are appended to the internal buffer so they can be read. + * + * @author Niall Gallagher + */ +public class FixedLengthConsumer extends UpdateConsumer { + + /** + * This is the allocator used to allocate the buffer used. + */ + private Allocator allocator; + + /** + * This is the internal buffer used to accumulate the body. + */ + private Buffer buffer; + + /** + * This is the number of bytes to be consumed from the cursor. + */ + private long limit; + + /** + * Constructor for the <code>FixedLengthConsumer</code> object. This + * is used to create a consumer that reads a fixed number of bytes + * from a cursor and accumulates those bytes in an internal buffer + * so that it can be read at a later stage. + * + * @param allocator this is used to allocate the internal buffer + * @param limit this is the number of bytes that are to be read + */ + public FixedLengthConsumer(Allocator allocator, long limit) { + this.allocator = allocator; + this.limit = limit; + } + + + /** + * This is used to acquire the body that has been consumed. This + * will return a body which can be used to read the content of + * the message, also if the request is multipart upload then all + * of the parts are provided as <code>Attachment</code> objects. + * Each part can then be read as an individual message. + * + * @return the body that has been consumed by this instance + */ + public Body getBody() { + return new BufferBody(buffer); + } + + /** + * This method is used to append the contents of the array to the + * internal buffer. The appended bytes can be acquired from the + * internal buffer using an <code>InputStream</code>, or the text + * of the appended bytes can be acquired by encoding the bytes. + * + * @param array this is the array of bytes to be appended + * @param off this is the start offset in the array to read from + * @param len this is the number of bytes to write to the buffer + */ + private void append(byte[] array, int off, int len) throws IOException { + if(buffer == null) { + buffer = allocator.allocate(limit); + } + buffer.append(array, off, len); + } + + /** + * This is used to process the bytes that have been read from the + * cursor. This will count the number of bytes read, once all of + * the bytes that form the body have been read this returns the + * number of bytes that represent the overflow. + * + * @param array this is a chunk read from the cursor + * @param off this is the offset within the array the chunk starts + * @param count this is the number of bytes within the array + * + * @return this returns the number of bytes overflow that is read + */ + @Override + protected int update(byte[] array, int off, int count) throws IOException { + int mark = (int)limit; + + if(count >= limit) { + append(array, off, mark); + finished = true; + limit = 0; + return count - mark; + } + if(count > 0) { + append(array, off, count); + limit -= count; + } + return 0; + } +} + + |