replace.java

来自「EXCEL read and write」· Java 代码 · 共 71 行

/* ====================================================================
   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
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       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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   See the License for the specific language governing permissions and
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package org.apache.poi.hssf.record.formula.functions;

import org.apache.poi.hssf.record.formula.eval.ErrorEval;
import org.apache.poi.hssf.record.formula.eval.Eval;
import org.apache.poi.hssf.record.formula.eval.EvaluationException;
import org.apache.poi.hssf.record.formula.eval.StringEval;
import org.apache.poi.hssf.record.formula.eval.ValueEval;

/**
 * An implementation of the Excel REPLACE() function<p/>:
 * Replaces part of a text string based on the number of characters
 * you specify, with another text string.<br/>
 *
 * <b>Syntax</b>:<br/>
 * <b>REPLACE</b>(<b>oldText</b>, <b>startNum</b>, <b>numChars</b>, <b>newText</b>)<p/>
 *
 * <b>oldText</b>  The text string containing characters to replace<br/>
 * <b>startNum</b> The position of the first character to replace (1-based)<br/>
 * <b>numChars</b> The number of characters to replace<br/>
 * <b>newText</b> The new text value to replace the removed section<br/>
 *
 * @author Manda Wilson &lt; wilson at c bio dot msk cc dot org &gt;
 */
public final class Replace extends TextFunction {

	protected ValueEval evaluateFunc(Eval[] args, int srcCellRow, short srcCellCol)
		throws EvaluationException {
		if (args.length != 4) {
			return ErrorEval.VALUE_INVALID;
		}

		String oldStr = evaluateStringArg(args[0], srcCellRow, srcCellCol);
		int startNum = evaluateIntArg(args[1], srcCellRow, srcCellCol);
		int numChars = evaluateIntArg(args[2], srcCellRow, srcCellCol);
		String newStr = evaluateStringArg(args[3], srcCellRow, srcCellCol);

		if (startNum < 1 || numChars < 0) {
			return ErrorEval.VALUE_INVALID;
		}
		StringBuffer strBuff = new StringBuffer(oldStr);
		// remove any characters that should be replaced
		if (startNum <= oldStr.length() && numChars != 0) {
			strBuff.delete(startNum - 1, startNum - 1 + numChars);
		}
		// now insert (or append) newStr
		if (startNum > strBuff.length()) {
			strBuff.append(newStr);
		} else {
			strBuff.insert(startNum - 1, newStr);
		}
		return new StringEval(strBuff.toString());
	}
}