/*
* Copyright 2006-2014 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.batch.item.file.transform;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Tokenizer used to process data obtained from files with fixed-length format.
* Columns are specified by array of Range objects ({@link #setColumns(Range[])}
* ).
*
* @author tomas.slanina
* @author peter.zozom
* @author Dave Syer
* @author Lucas Ward
* @author Michael Minella
*/
public class FixedLengthTokenizer extends AbstractLineTokenizer {
private Range[] ranges;
private int maxRange = 0;
boolean open = false;
/**
* Set the column ranges. Used in conjunction with the
* {@link RangeArrayPropertyEditor} this property can be set in the form of
* a String describing the range boundaries, e.g. "1,4,7" or "1-3,4-6,7" or
* "1-2,4-5,7-10". If the last range is open then the rest of the line is
* read into that column (irrespective of the strict flag setting).
*
* @see #setStrict(boolean)
*
* @param ranges the column ranges expected in the input
*/
public void setColumns(Range[] ranges) {
this.ranges = Arrays.asList(ranges).toArray(new Range[ranges.length]);
calculateMaxRange(ranges);
}
/*
* Calculate the highest value within an array of ranges. The ranges aren't
* necessarily in order. For example: "5-10, 1-4,11-15". Furthermore, there
* isn't always a min and max, such as: "1,4-20, 22"
*/
private void calculateMaxRange(Range[] ranges) {
if (ranges == null || ranges.length == 0) {
maxRange = 0;
return;
}
open = false;
maxRange = ranges[0].getMin();
for (int i = 0; i < ranges.length; i++) {
int upperBound;
if (ranges[i].hasMaxValue()) {
upperBound = ranges[i].getMax();
}
else {
upperBound = ranges[i].getMin();
if (upperBound > maxRange) {
open = true;
}
}
if (upperBound > maxRange) {
maxRange = upperBound;
}
}
}
/**
* Yields the tokens resulting from the splitting of the supplied
* <code>line</code>.
*
* @param line the line to be tokenized (can be <code>null</code>)
*
* @return the resulting tokens (empty if the line is null)
* @throws IncorrectLineLengthException if line length is greater than or
* less than the max range set.
*/
@Override
protected List<String> doTokenize(String line) {
List<String> tokens = new ArrayList<String>(ranges.length);
int lineLength;
String token;
lineLength = line.length();
if (lineLength < maxRange && isStrict()) {
throw new IncorrectLineLengthException("Line is shorter than max range " + maxRange, maxRange, lineLength, line);
}
if (!open && lineLength > maxRange && isStrict()) {
throw new IncorrectLineLengthException("Line is longer than max range " + maxRange, maxRange, lineLength, line);
}
for (int i = 0; i < ranges.length; i++) {
int startPos = ranges[i].getMin() - 1;
int endPos = ranges[i].getMax();
if (lineLength >= endPos) {
token = line.substring(startPos, endPos);
}
else if (lineLength >= startPos) {
token = line.substring(startPos);
}
else {
token = "";
}
tokens.add(token);
}
return tokens;
}
}