Java tutorial
package org.skyscreamer.nevado.jms.message; import org.apache.commons.lang.builder.HashCodeBuilder; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.jms.*; import java.io.*; /** * This class borrrows heavily from ActiveMQStreamMessage, Copyright 2004 Protique Ltd, * with great appreciation for its creators. It is also licensed under Apache 2.0. * * 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. */ public class NevadoBytesMessage extends NevadoMessage implements BytesMessage { transient private Log _log = LogFactory.getLog(NevadoBytesMessage.class); private ByteArray _body; public NevadoBytesMessage() { } protected NevadoBytesMessage(BytesMessage message) throws JMSException { super(message); message.reset(); for (int count = 0; count < message.getBodyLength();) { byte[] buffer = new byte[10240]; int numRead = message.readBytes(buffer); writeBytes(buffer, 0, numRead); count += numRead; } } @Override public void internalClearBody() throws JMSException { _body = null; this.dataOut = null; this.dataIn = null; this.bytesOut = null; } private transient DataOutputStream dataOut; private transient ByteArrayOutputStream bytesOut; private transient DataInputStream dataIn; public void onSend() { super.onSend(); storeContent(); } private void storeContent() { if (dataOut != null) { try { dataOut.close(); _body = new ByteArray(bytesOut.toByteArray()); bytesOut = null; dataOut = null; } catch (IOException ioe) { // Since this is backed by memory, it's rare enough to turn to a runtime throw new RuntimeException(ioe); } } } /** * @param bodyAsBytes The bodyAsBytes to set. * @param offset * @param length */ public void setBodyAsBytes(byte[] bodyAsBytes, int offset, int length) { _body = new ByteArray(bodyAsBytes, offset, length); dataOut = null; dataIn = null; bytesOut = null; } /** * Gets the number of bytes of the message body when the message is in read-only mode. The value returned can be * used to allocate a byte array. The value returned is the entire length of the message body, regardless of where * the pointer for reading the message is currently located. * * @return number of bytes in the message * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageNotReadableException if the message is in write-only mode. * @since 1.1 */ public long getBodyLength() throws JMSException { checkWriteOnlyBody(); return _body.size(); } /** * Reads a <code>boolean</code> from the bytes message stream. * * @return the <code>boolean</code> value read * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public boolean readBoolean() throws JMSException { initializeReading(); try { return this.dataIn.readBoolean(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a signed 8-bit value from the bytes message stream. * * @return the next byte from the bytes message stream as a signed 8-bit <code>byte</code> * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public byte readByte() throws JMSException { initializeReading(); try { return this.dataIn.readByte(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads an unsigned 8-bit number from the bytes message stream. * * @return the next byte from the bytes message stream, interpreted as an unsigned 8-bit number * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public int readUnsignedByte() throws JMSException { initializeReading(); try { return this.dataIn.readUnsignedByte(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a signed 16-bit number from the bytes message stream. * * @return the next two bytes from the bytes message stream, interpreted as a signed 16-bit number * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public short readShort() throws JMSException { initializeReading(); try { return this.dataIn.readShort(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads an unsigned 16-bit number from the bytes message stream. * * @return the next two bytes from the bytes message stream, interpreted as an unsigned 16-bit integer * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public int readUnsignedShort() throws JMSException { initializeReading(); try { return this.dataIn.readUnsignedShort(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a Unicode character value from the bytes message stream. * * @return the next two bytes from the bytes message stream as a Unicode character * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public char readChar() throws JMSException { initializeReading(); try { return this.dataIn.readChar(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a signed 32-bit integer from the bytes message stream. * * @return the next four bytes from the bytes message stream, interpreted as an <code>int</code> * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public int readInt() throws JMSException { initializeReading(); try { return this.dataIn.readInt(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a signed 64-bit integer from the bytes message stream. * * @return the next eight bytes from the bytes message stream, interpreted as a <code>long</code> * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public long readLong() throws JMSException { initializeReading(); try { return this.dataIn.readLong(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a <code>float</code> from the bytes message stream. * * @return the next four bytes from the bytes message stream, interpreted as a <code>float</code> * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public float readFloat() throws JMSException { initializeReading(); try { return this.dataIn.readFloat(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a <code>double</code> from the bytes message stream. * * @return the next eight bytes from the bytes message stream, interpreted as a <code>double</code> * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public double readDouble() throws JMSException { initializeReading(); try { return this.dataIn.readDouble(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a string that has been encoded using a modified UTF-8 format from the bytes message stream. * <P> * For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open * Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC * 10646, Annex P. * * @return a Unicode string from the bytes message stream * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageEOFException if unexpected end of bytes stream has been reached. * @throws MessageNotReadableException if the message is in write-only mode. */ public String readUTF() throws JMSException { initializeReading(); try { return this.dataIn.readUTF(); } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Reads a byte array from the bytes message stream. * <P> * If the length of array <code>value</code> is less than the number of bytes remaining to be read from the * stream, the array should be filled. A subsequent call reads the next increment, and so on. * <P> * If the number of bytes remaining in the stream is less than the length of array <code>value</code>, the bytes * should be read into the array. The return value of the total number of bytes read will be less than the length * of the array, indicating that there are no more bytes left to be read from the stream. The next read of the * stream returns -1. * * @param value the buffer into which the data is read * @return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the * stream has been reached * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageNotReadableException if the message is in write-only mode. */ public int readBytes(byte[] value) throws JMSException { return readBytes(value, value.length); } /** * Reads a portion of the bytes message stream. * <P> * If the length of array <code>value</code> is less than the number of bytes remaining to be read from the * stream, the array should be filled. A subsequent call reads the next increment, and so on. * <P> * If the number of bytes remaining in the stream is less than the length of array <code>value</code>, the bytes * should be read into the array. The return value of the total number of bytes read will be less than the length * of the array, indicating that there are no more bytes left to be read from the stream. The next read of the * stream returns -1. * <p/> * If <code>length</code> is negative, or <code>length</code> is greater than the length of the array <code>value</code>, * then an <code>IndexOutOfBoundsException</code> is thrown. No bytes will be read from the stream for this * exception case. * * @param value the buffer into which the data is read * @param length the number of bytes to read; must be less than or equal to <code>value.length</code> * @return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the * stream has been reached * @throws JMSException if the JMS provider fails to read the message due to some internal error. * @throws MessageNotReadableException if the message is in write-only mode. */ public int readBytes(byte[] value, int length) throws JMSException { initializeReading(); try { int n = 0; while (n < length) { int count = this.dataIn.read(value, n, length - n); if (count < 0) { break; } n += count; } if (n == 0 && length > 0) { n = -1; } return n; } catch (EOFException eof) { JMSException jmsEx = new MessageEOFException(eof.getMessage()); jmsEx.setLinkedException(eof); throw jmsEx; } catch (IOException ioe) { JMSException jmsEx = new JMSException("Format error occured" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a <code>boolean</code> to the bytes message stream as a 1-byte value. The value <code>true</code> is * written as the value <code>(byte)1</code>; the value <code>false</code> is written as the value <code>(byte)0</code>. * * @param value the <code>boolean</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeBoolean(boolean value) throws JMSException { initializeWriting(); try { this.dataOut.writeBoolean(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a <code>byte</code> to the bytes message stream as a 1-byte value. * * @param value the <code>byte</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeByte(byte value) throws JMSException { initializeWriting(); try { this.dataOut.writeByte(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a <code>short</code> to the bytes message stream as two bytes, high byte first. * * @param value the <code>short</code> to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeShort(short value) throws JMSException { initializeWriting(); try { this.dataOut.writeShort(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a <code>char</code> to the bytes message stream as a 2-byte value, high byte first. * * @param value the <code>char</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeChar(char value) throws JMSException { initializeWriting(); try { this.dataOut.writeChar(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes an <code>int</code> to the bytes message stream as four bytes, high byte first. * * @param value the <code>int</code> to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeInt(int value) throws JMSException { initializeWriting(); try { this.dataOut.writeInt(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a <code>long</code> to the bytes message stream as eight bytes, high byte first. * * @param value the <code>long</code> to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeLong(long value) throws JMSException { initializeWriting(); try { this.dataOut.writeLong(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Converts the <code>float</code> argument to an <code>int</code> using the <code>floatToIntBits</code> * method in class <code>Float</code>, and then writes that <code>int</code> value to the bytes message stream * as a 4-byte quantity, high byte first. * * @param value the <code>float</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeFloat(float value) throws JMSException { initializeWriting(); try { this.dataOut.writeFloat(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Converts the <code>double</code> argument to a <code>long</code> using the <code>doubleToLongBits</code> * method in class <code>Double</code>, and then writes that <code>long</code> value to the bytes message * stream as an 8-byte quantity, high byte first. * * @param value the <code>double</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeDouble(double value) throws JMSException { initializeWriting(); try { this.dataOut.writeDouble(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a string to the bytes message stream using UTF-8 encoding in a machine-independent manner. * <P> * For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open * Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC * 10646, Annex P. * * @param value the <code>String</code> value to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeUTF(String value) throws JMSException { initializeWriting(); try { this.dataOut.writeUTF(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a byte array to the bytes message stream. * * @param value the byte array to be written * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeBytes(byte[] value) throws JMSException { initializeWriting(); try { this.dataOut.write(value); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes a portion of a byte array to the bytes message stream. * * @param value the byte array value to be written * @param offset the initial offset within the byte array * @param length the number of bytes to use * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageNotWriteableException if the message is in read-only mode. */ public void writeBytes(byte[] value, int offset, int length) throws JMSException { initializeWriting(); try { this.dataOut.write(value, offset, length); } catch (IOException ioe) { JMSException jmsEx = new JMSException("Could not write data:" + ioe.getMessage()); jmsEx.setLinkedException(ioe); throw jmsEx; } } /** * Writes an object to the bytes message stream. * <P> * This method works only for the objectified primitive object types (<code>Integer</code>,<code>Double</code>, * <code>Long</code> ...), <code>String</code> objects, and byte arrays. * * @param value the object in the Java programming language ("Java object") to be written; it must not be null * @throws JMSException if the JMS provider fails to write the message due to some internal error. * @throws MessageFormatException if the object is of an invalid type. * @throws MessageNotWriteableException if the message is in read-only mode. * @throws java.lang.NullPointerException if the parameter <code>value</code> is null. */ public void writeObject(Object value) throws JMSException { if (value == null) { throw new NullPointerException(); } initializeWriting(); if (value instanceof Boolean) { writeBoolean(((Boolean) value).booleanValue()); } else if (value instanceof Character) { writeChar(((Character) value).charValue()); } else if (value instanceof Byte) { writeByte(((Byte) value).byteValue()); } else if (value instanceof Short) { writeShort(((Short) value).shortValue()); } else if (value instanceof Integer) { writeInt(((Integer) value).intValue()); } else if (value instanceof Double) { writeDouble(((Double) value).doubleValue()); } else if (value instanceof Long) { writeLong(((Long) value).longValue()); } else if (value instanceof Float) { writeFloat(((Float) value).floatValue()); } else if (value instanceof Double) { writeDouble(((Double) value).doubleValue()); } else if (value instanceof String) { writeUTF(value.toString()); } else if (value instanceof byte[]) { writeBytes((byte[]) value); } else { throw new MessageFormatException("Cannot write non-primitive type:" + value.getClass()); } } /** * Puts the message body in read-only mode and repositions the stream of bytes to the beginning. * * @throws JMSException if an internal error occurs */ public void reset() throws JMSException { storeContent(); this.bytesOut = null; this.dataIn = null; this.dataOut = null; } private void initializeWriting() throws MessageNotWriteableException { checkReadOnlyBody(); if (this.dataOut == null) { this.bytesOut = new ByteArrayOutputStream(); this.dataOut = new DataOutputStream(this.bytesOut); } } private void initializeReading() throws MessageNotReadableException { checkWriteOnlyBody(); if (this.dataIn == null) { ByteArrayInputStream bytesIn = new ByteArrayInputStream(_body.toByteArray()); this.dataIn = new DataInputStream(bytesIn); } } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; NevadoBytesMessage that = (NevadoBytesMessage) o; if (_messageID != null ? !_messageID.equals(that._messageID) : that._messageID != null) return false; if (_body != null ? !_body.equals(that._body) : that._body != null) return false; return true; } @Override public int hashCode() { return new HashCodeBuilder().append(_messageID).append(_body).toHashCode(); } }