org.wso2.extension.siddhi.io.file.FileSink Maven / Gradle / Ivy
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/*
* Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. 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.
*/
package org.wso2.extension.siddhi.io.file;
import org.apache.log4j.Logger;
import org.wso2.carbon.messaging.BinaryCarbonMessage;
import org.wso2.carbon.messaging.exceptions.ClientConnectorException;
import org.wso2.extension.siddhi.io.file.util.Constants;
import org.wso2.siddhi.annotation.Example;
import org.wso2.siddhi.annotation.Extension;
import org.wso2.siddhi.annotation.Parameter;
import org.wso2.siddhi.annotation.util.DataType;
import org.wso2.siddhi.core.config.SiddhiAppContext;
import org.wso2.siddhi.core.exception.ConnectionUnavailableException;
import org.wso2.siddhi.core.stream.output.sink.Sink;
import org.wso2.siddhi.core.util.config.ConfigReader;
import org.wso2.siddhi.core.util.transport.DynamicOptions;
import org.wso2.siddhi.core.util.transport.Option;
import org.wso2.siddhi.core.util.transport.OptionHolder;
import org.wso2.siddhi.query.api.definition.StreamDefinition;
import org.wso2.transport.file.connector.sender.VFSClientConnector;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
/**
* This class contains the implementation of siddhi-io-file sink which provides the functionality of
* publishing data to files through siddhi.
*/
@Extension(
name = "file" ,
namespace = "sink" ,
description = "" +
"File Sink can be used to publish (write) event data which is processed within siddhi " +
"to files. \nSiddhi-io-file sink provides support to write both textual and binary data into files\n",
parameters = {
@Parameter(name = "file.uri",
description =
"Used to specify the file for data to be written. ",
type = {DataType.STRING},
dynamic = true
),
@Parameter(name = "append",
description = "" +
"This parameter is used to specify whether the data should be " +
"append to the file or not.\n" +
"If append = 'true', " +
"data will be write at the end of the file without " +
"changing the existing content.\n" +
"If file does not exist, a new fill will be crated and then data will be written.\n" +
"If append append = 'false', \n" +
"If given file exists, existing content will be deleted and then data will be " +
"written back to the file.\n" +
"If given file does not exist, a new file will be created and " +
"then data will be written on it.\n",
type = {DataType.BOOL},
optional = true,
defaultValue = "true"
),
@Parameter(
name = "add.line.separator",
description = "This parameter is used to specify whether events added to the file should " +
"be separated by a newline.\n" +
"If add.event.separator= 'true'," +
"then a newline will be added after data is added to the file.",
type = {DataType.BOOL},
optional = true,
defaultValue = "true. (However, if csv mapper is used, it is false)"
)
},
examples = {
@Example(
syntax = "" +
"@sink(type='file', @map(type='json'), " +
"append='false', " +
"file.uri='/abc/{{symbol}}.txt') " +
"define stream BarStream (symbol string, price float, volume long); ",
description = "" +
"Under above configuration, for each event, " +
"a file will be generated if there's no such a file," +
"and then data will be written to that file as json messages" +
"output will looks like below.\n" +
"{\n" +
" \"event\":{\n" +
" \"symbol\":\"WSO2\",\n" +
" \"price\":55.6,\n" +
" \"volume\":100\n" +
" }\n" +
"}\n")
}
)
public class FileSink extends Sink {
private static final Logger log = Logger.getLogger(FileSink.class);
private VFSClientConnector vfsClientConnector = null;
private Map properties = null;
private Option uriOption;
private SiddhiAppContext siddhiAppContext;
private boolean addEventSeparator;
@Override
public Class[] getSupportedInputEventClasses() {
return new Class[]{String.class, byte[].class, Object.class};
}
public String[] getSupportedDynamicOptions() {
return new String[]{Constants.FILE_URI};
}
protected void init(StreamDefinition streamDefinition, OptionHolder optionHolder,
ConfigReader configReader, SiddhiAppContext siddhiAppContext) {
this.siddhiAppContext = siddhiAppContext;
uriOption = optionHolder.validateAndGetOption(Constants.FILE_URI);
String append = optionHolder.validateAndGetStaticValue(Constants.APPEND, Constants.TRUE);
properties = new HashMap<>();
properties.put(Constants.ACTION, Constants.WRITE);
if (Constants.TRUE.equalsIgnoreCase(append)) {
properties.put(Constants.APPEND, append);
}
String mapType = streamDefinition.getAnnotations().get(0).getAnnotations().get(0).getElements().get(0)
.getValue();
addEventSeparator = optionHolder.isOptionExists(Constants.ADD_EVENT_SEPARATOR) ?
Boolean.parseBoolean(optionHolder.validateAndGetStaticValue(Constants.ADD_EVENT_SEPARATOR)) :
!mapType.equalsIgnoreCase("csv");
}
public void connect() throws ConnectionUnavailableException {
vfsClientConnector = new VFSClientConnector();
}
public void disconnect() {
}
public void destroy() {
}
public void publish(Object payload, DynamicOptions dynamicOptions) throws ConnectionUnavailableException {
byte[] byteArray = new byte[0];
boolean canBeWritten = true;
if (payload instanceof byte[]) {
byteArray = (byte[]) payload;
} else {
try {
StringBuilder sb = new StringBuilder();
sb.append(payload.toString());
if (this.addEventSeparator) {
sb.append("\n");
}
byteArray = sb.toString().getBytes(Constants.UTF_8);
} catch (UnsupportedEncodingException e) {
canBeWritten = false;
log.error("Received payload does not support UTF-8 encoding. Hence dropping the event." , e);
}
}
if (canBeWritten) {
String uri = uriOption.getValue(dynamicOptions);
BinaryCarbonMessage binaryCarbonMessage = new BinaryCarbonMessage(ByteBuffer.wrap(byteArray), true);
properties.put(Constants.URI, uri);
try {
vfsClientConnector.send(binaryCarbonMessage, null, properties);
} catch (ClientConnectorException e) {
throw new ConnectionUnavailableException("Writing data into the file " + uri + " failed during the " +
"execution of '" + siddhiAppContext.getName() + "' SiddhiApp, due to " +
e.getMessage(), e);
}
}
}
public Map currentState() {
return new HashMap<>();
}
public void restoreState(Map map) {
//do nothing
}
}
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