/*
* 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.api.java.io;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.api.common.io.DelimitedInputFormat;
import org.apache.flink.core.fs.FileInputSplit;
import org.apache.flink.core.fs.Path;
import org.apache.flink.types.parser.FieldParser;
import org.apache.flink.util.InstantiationUtil;
import java.io.IOException;
/**
* An input format that reads single field primitive data from a given file. The difference between this and
* {@link org.apache.flink.api.java.io.CsvInputFormat} is that it won't go through {@link org.apache.flink.api.java.tuple.Tuple1}.
*/
@PublicEvolving
public class PrimitiveInputFormat<OT> extends DelimitedInputFormat<OT> {
private static final long serialVersionUID = 1L;
private Class<OT> primitiveClass;
private static final byte CARRIAGE_RETURN = (byte) '\r';
private static final byte NEW_LINE = (byte) '\n';
private transient FieldParser<OT> parser;
public PrimitiveInputFormat(Path filePath, Class<OT> primitiveClass) {
super(filePath, null);
this.primitiveClass = primitiveClass;
}
public PrimitiveInputFormat(Path filePath, String delimiter, Class<OT> primitiveClass) {
super(filePath, null);
this.primitiveClass = primitiveClass;
this.setDelimiter(delimiter);
}
@Override
public void open(FileInputSplit split) throws IOException {
super.open(split);
Class<? extends FieldParser<OT>> parserType = FieldParser.getParserForType(primitiveClass);
if (parserType == null) {
throw new IllegalArgumentException("The type '" + primitiveClass.getName() + "' is not supported for the primitive input format.");
}
parser = InstantiationUtil.instantiate(parserType, FieldParser.class);
}
@Override
public OT readRecord(OT reuse, byte[] bytes, int offset, int numBytes) throws IOException {
// Check if \n is used as delimiter and the end of this line is a \r, then remove \r from the line
if (this.getDelimiter().length == 1 && this.getDelimiter()[0] == NEW_LINE
&& offset+numBytes >= 1 && bytes[offset+numBytes-1] == CARRIAGE_RETURN){
numBytes -= 1;
}
// Null character as delimiter is used because there's only 1 field to be parsed
if (parser.resetErrorStateAndParse(bytes, offset, numBytes + offset, new byte[]{'\0'}, reuse) >= 0) {
return parser.getLastResult();
} else {
String s = new String(bytes, offset, numBytes, getCharset());
throw new IOException("Could not parse value: \""+s+"\" as type "+primitiveClass.getSimpleName());
}
}
}