| /* |
| * 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. |
| */ |
| /* |
| * $Id: FuncSubstring.java 468655 2006-10-28 07:12:06Z minchau $ |
| */ |
| package org.apache.xpath.functions; |
| |
| import org.apache.xalan.res.XSLMessages; |
| import org.apache.xml.utils.XMLString; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.objects.XString; |
| import org.apache.xpath.res.XPATHErrorResources; |
| |
| /** |
| * Execute the Substring() function. |
| * @xsl.usage advanced |
| */ |
| public class FuncSubstring extends Function3Args |
| { |
| static final long serialVersionUID = -5996676095024715502L; |
| |
| /** |
| * Execute the function. The function must return |
| * a valid object. |
| * @param xctxt The current execution context. |
| * @return A valid XObject. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException |
| { |
| |
| XMLString s1 = m_arg0.execute(xctxt).xstr(); |
| double start = m_arg1.execute(xctxt).num(); |
| int lenOfS1 = s1.length(); |
| XMLString substr; |
| |
| if (lenOfS1 <= 0) |
| return XString.EMPTYSTRING; |
| else |
| { |
| int startIndex; |
| |
| if (Double.isNaN(start)) |
| { |
| |
| // Double.MIN_VALUE doesn't work with math below |
| // so just use a big number and hope I never get caught. |
| start = -1000000; |
| startIndex = 0; |
| } |
| else |
| { |
| start = Math.round(start); |
| startIndex = (start > 0) ? (int) start - 1 : 0; |
| } |
| |
| if (null != m_arg2) |
| { |
| double len = m_arg2.num(xctxt); |
| int end = (int) (Math.round(len) + start) - 1; |
| |
| // Normalize end index. |
| if (end < 0) |
| end = 0; |
| else if (end > lenOfS1) |
| end = lenOfS1; |
| |
| if (startIndex > lenOfS1) |
| startIndex = lenOfS1; |
| |
| substr = s1.substring(startIndex, end); |
| } |
| else |
| { |
| if (startIndex > lenOfS1) |
| startIndex = lenOfS1; |
| substr = s1.substring(startIndex); |
| } |
| } |
| |
| return (XString)substr; // cast semi-safe |
| } |
| |
| /** |
| * Check that the number of arguments passed to this function is correct. |
| * |
| * |
| * @param argNum The number of arguments that is being passed to the function. |
| * |
| * @throws WrongNumberArgsException |
| */ |
| public void checkNumberArgs(int argNum) throws WrongNumberArgsException |
| { |
| if (argNum < 2) |
| reportWrongNumberArgs(); |
| } |
| |
| /** |
| * Constructs and throws a WrongNumberArgException with the appropriate |
| * message for this function object. |
| * |
| * @throws WrongNumberArgsException |
| */ |
| protected void reportWrongNumberArgs() throws WrongNumberArgsException { |
| throw new WrongNumberArgsException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_TWO_OR_THREE, null)); //"2 or 3"); |
| } |
| } |