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The RabbitMQ Java client library allows Java applications to interface with RabbitMQ.
// Copyright (c) 2007-2019 Pivotal Software, Inc. All rights reserved.
//
// This software, the RabbitMQ Java client library, is triple-licensed under the
// Mozilla Public License 1.1 ("MPL"), the GNU General Public License version 2
// ("GPL") and the Apache License version 2 ("ASL"). For the MPL, please see
// LICENSE-MPL-RabbitMQ. For the GPL, please see LICENSE-GPL2. For the ASL,
// please see LICENSE-APACHE2.
//
// This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND,
// either express or implied. See the LICENSE file for specific language governing
// rights and limitations of this software.
//
// If you have any questions regarding licensing, please contact us at
// [email protected].
package com.rabbitmq.client.impl;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Date;
import java.util.Map;
import java.util.List;
import com.rabbitmq.client.LongString;
/**
* Helper class to generate AMQP wire-protocol encoded values.
*/
public class ValueWriter
{
private final DataOutputStream out;
public ValueWriter(DataOutputStream out)
{
this.out = out;
}
/** Public API - encodes a short string. */
public final void writeShortstr(String str)
throws IOException
{
byte [] bytes = str.getBytes("utf-8");
int length = bytes.length;
if (length > 255) {
throw new IllegalArgumentException(
"Short string too long; utf-8 encoded length = " + length +
", max = 255.");
}
out.writeByte(bytes.length);
out.write(bytes);
}
/** Public API - encodes a long string from a LongString. */
public final void writeLongstr(LongString str)
throws IOException
{
writeLong((int)str.length());
copy(str.getStream(), out);
}
private static final int COPY_BUFFER_SIZE = 4096;
private static void copy(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[COPY_BUFFER_SIZE];
int biteSize = input.read(buffer);
while (-1 != biteSize) {
output.write(buffer, 0, biteSize);
biteSize = input.read(buffer);
}
}
/** Public API - encodes a long string from a String. */
public final void writeLongstr(String str)
throws IOException
{
byte [] bytes = str.getBytes("utf-8");
writeLong(bytes.length);
out.write(bytes);
}
/** Public API - encodes a short integer. */
public final void writeShort(int s)
throws IOException
{
out.writeShort(s);
}
/** Public API - encodes an integer. */
public final void writeLong(int l)
throws IOException
{
// java's arithmetic on this type is signed, however it's
// reasonable to use ints to represent the unsigned long
// type - for values < Integer.MAX_VALUE everything works
// as expected
out.writeInt(l);
}
/** Public API - encodes a long integer. */
public final void writeLonglong(long ll)
throws IOException
{
out.writeLong(ll);
}
/** Public API - encodes a table. */
public final void writeTable(Map table)
throws IOException
{
if (table == null) {
// Convenience.
out.writeInt(0);
} else {
out.writeInt((int)Frame.tableSize(table));
for(Map.Entry entry: table.entrySet()) {
writeShortstr(entry.getKey());
Object value = entry.getValue();
writeFieldValue(value);
}
}
}
public final void writeFieldValue(Object value)
throws IOException
{
if(value instanceof String) {
writeOctet('S');
writeLongstr((String)value);
}
else if(value instanceof LongString) {
writeOctet('S');
writeLongstr((LongString)value);
}
else if(value instanceof Integer) {
writeOctet('I');
writeLong((Integer) value);
}
else if(value instanceof BigDecimal) {
writeOctet('D');
BigDecimal decimal = (BigDecimal)value;
// The scale must be an unsigned octet, therefore its values must
// be between 0 and 255
if(decimal.scale() > 255 || decimal.scale() < 0)
throw new IllegalArgumentException
("BigDecimal has too large of a scale to be encoded. " +
"The scale was: " + decimal.scale());
writeOctet(decimal.scale());
BigInteger unscaled = decimal.unscaledValue();
// We use 31 instead of 32 (Integer.SIZE) because bitLength ignores the sign bit,
// so e.g. new BigDecimal(Integer.MAX_VALUE) comes out to 31 bits.
if(unscaled.bitLength() > 31)
throw new IllegalArgumentException
("BigDecimal too large to be encoded");
writeLong(decimal.unscaledValue().intValue());
}
else if(value instanceof Date) {
writeOctet('T');
writeTimestamp((Date)value);
}
else if(value instanceof Map) {
writeOctet('F');
// Ignore the warnings here. We hate erasure
// (not even a little respect)
// (We even have trouble recognising it.)
@SuppressWarnings("unchecked")
Map map = (Map) value;
writeTable(map);
}
else if (value instanceof Byte) {
writeOctet('b');
out.writeByte((Byte)value);
}
else if(value instanceof Double) {
writeOctet('d');
out.writeDouble((Double)value);
}
else if(value instanceof Float) {
writeOctet('f');
out.writeFloat((Float)value);
}
else if(value instanceof Long) {
writeOctet('l');
out.writeLong((Long)value);
}
else if(value instanceof Short) {
writeOctet('s');
out.writeShort((Short)value);
}
else if(value instanceof Boolean) {
writeOctet('t');
out.writeBoolean((Boolean)value);
}
else if(value instanceof byte[]) {
writeOctet('x');
writeLong(((byte[])value).length);
out.write((byte[])value);
}
else if(value == null) {
writeOctet('V');
}
else if(value instanceof List) {
writeOctet('A');
writeArray((List)value);
}
else if(value instanceof Object[]) {
writeOctet('A');
writeArray((Object[])value);
}
else {
throw new IllegalArgumentException
("Invalid value type: " + value.getClass().getName());
}
}
public final void writeArray(List value)
throws IOException
{
if (value==null) {
out.write(0);
}
else {
out.writeInt((int)Frame.arraySize(value));
for (Object item : value) {
writeFieldValue(item);
}
}
}
public final void writeArray(Object[] value)
throws IOException
{
if (value==null) {
out.write(0);
}
else {
out.writeInt((int)Frame.arraySize(value));
for (Object item : value) {
writeFieldValue(item);
}
}
}
/** Public API - encodes an octet from an int. */
public final void writeOctet(int octet)
throws IOException
{
out.writeByte(octet);
}
/** Public API - encodes an octet from a byte. */
public final void writeOctet(byte octet)
throws IOException
{
out.writeByte(octet);
}
/** Public API - encodes a timestamp. */
public final void writeTimestamp(Date timestamp)
throws IOException
{
// AMQP uses POSIX time_t which is in seconds since the epoch began
writeLonglong(timestamp.getTime()/1000);
}
/**
* Public API - call this to ensure all accumulated
* values are correctly written to the output stream.
*/
public void flush()
throws IOException
{
out.flush();
}
}