Java tutorial
/* * Copyright 2013-2014 the original author or authors. * * 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.springframework.cloud.aws.messaging.support.converter; import org.apache.commons.codec.binary.Base64; import org.apache.commons.codec.binary.Base64InputStream; import org.apache.commons.codec.binary.Base64OutputStream; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.messaging.Message; import org.springframework.messaging.MessageHeaders; import org.springframework.messaging.converter.AbstractMessageConverter; import org.springframework.messaging.converter.MessageConversionException; import org.springframework.util.MimeType; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.nio.charset.Charset; /** * @author Agim Emruli */ public class ObjectMessageConverter extends AbstractMessageConverter { private static final Logger LOGGER = LoggerFactory.getLogger(ObjectMessageConverter.class); private static final String DEFAULT_ENCODING = "UTF-8"; private final Charset encoding; public ObjectMessageConverter(String encoding) { super(new MimeType("application", "x-java-serialized-object", Charset.forName(encoding))); this.encoding = Charset.forName(encoding); } public ObjectMessageConverter() { this(DEFAULT_ENCODING); } @Override protected boolean supports(Class<?> clazz) { return true; } @Override public Object convertFromInternal(Message<?> message, Class<?> targetClass) { String messagePayload = message.getPayload().toString(); byte[] rawContent = messagePayload.getBytes(this.encoding); if (!(Base64.isBase64(rawContent))) { throw new MessageConversionException("Error converting payload '" + messagePayload + "' because it is not a valid base64 encoded stream!", null); } ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(rawContent); Base64InputStream base64InputStream = new Base64InputStream(byteArrayInputStream); Serializable result = null; ObjectInputStream objectInputStream = null; try { objectInputStream = new ObjectInputStream(base64InputStream); result = (Serializable) objectInputStream.readObject(); } catch (ClassNotFoundException e) { throw new MessageConversionException( "Error loading class from message payload, make sure class is in classpath!", e); } catch (IOException e) { throw new MessageConversionException("Error reading payload from binary representation", e); } finally { if (objectInputStream != null) { try { objectInputStream.close(); } catch (IOException e) { LOGGER.warn("Error closing object output stream while reading message payload", e); } } } return result; } @Override public Object convertToInternal(Object payload, MessageHeaders headers) { if (!(payload instanceof Serializable)) { throw new IllegalArgumentException("Can't convert payload, it must be of type Serializable"); } ByteArrayOutputStream content = new ByteArrayOutputStream(); Base64OutputStream base64OutputStream = new Base64OutputStream(content, true, 0, null); ObjectOutputStream objectOutputStream = null; try { objectOutputStream = new ObjectOutputStream(base64OutputStream); objectOutputStream.writeObject(payload); objectOutputStream.flush(); } catch (IOException e) { throw new MessageConversionException("Error converting payload into binary representation", e); } finally { if (objectOutputStream != null) { try { objectOutputStream.close(); } catch (IOException e) { LOGGER.warn("Error closing object output stream while writing message payload", e); } } } return new String(content.toByteArray(), 0, content.size(), this.encoding); } }