FileDocCategorySizeDatePackage
FuncSubstring.javaAPI DocJava SE 6 API3511Tue Jun 10 00:23:16 BST 2008com.sun.org.apache.xpath.internal.functions

FuncSubstring

public class FuncSubstring extends Function3Args
Execute the Substring() function.
xsl.usage
advanced

Fields Summary
static final long
serialVersionUID
Constructors Summary
Methods Summary
public voidcheckNumberArgs(int argNum)
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

    if (argNum < 2)
      reportWrongNumberArgs();
public com.sun.org.apache.xpath.internal.objects.XObjectexecute(com.sun.org.apache.xpath.internal.XPathContext xctxt)
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


                            
       
  

    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
protected voidreportWrongNumberArgs()
Constructs and throws a WrongNumberArgException with the appropriate message for this function object.

throws
WrongNumberArgsException

      throw new WrongNumberArgsException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_TWO_OR_THREE, null)); //"2 or 3");