/**
* 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.
*/
package org.apache.flink.streaming.connectors.fs;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
/**
* A {@link Writer} that uses {@code toString()} on the input elements and writes them to
* the output bucket file separated by newline.
*
* @param <T> The type of the elements that are being written by the sink.
*/
public class StringWriter<T> extends StreamWriterBase<T> {
private static final long serialVersionUID = 1L;
private String charsetName;
private transient Charset charset;
/**
* Creates a new {@code StringWriter} that uses {@code "UTF-8"} charset to convert
* strings to bytes.
*/
public StringWriter() {
this("UTF-8");
}
/**
* Creates a new {@code StringWriter} that uses the given charset to convert
* strings to bytes.
*
* @param charsetName Name of the charset to be used, must be valid input for {@code Charset.forName(charsetName)}
*/
public StringWriter(String charsetName) {
this.charsetName = charsetName;
}
@Override
public void open(FileSystem fs, Path path) throws IOException {
super.open(fs, path);
try {
this.charset = Charset.forName(charsetName);
}
catch (IllegalCharsetNameException e) {
throw new IOException("The charset " + charsetName + " is not valid.", e);
}
catch (UnsupportedCharsetException e) {
throw new IOException("The charset " + charsetName + " is not supported.", e);
}
}
@Override
public void write(T element) throws IOException {
FSDataOutputStream outputStream = getStream();
outputStream.write(element.toString().getBytes(charset));
outputStream.write('\n');
}
@Override
public Writer<T> duplicate() {
return new StringWriter<>();
}
}