/*****************************************************************************
SQLJEP - Java SQL Expression Parser 0.2
November 1 2006
(c) Copyright 2006, Alexey Gaidukov
SQLJEP Author: Alexey Gaidukov
SQLJEP is based on JEP 2.24 (http://www.singularsys.com/jep/)
(c) Copyright 2002, Nathan Funk
See LICENSE.txt for license information.
*****************************************************************************/
package com.meidusa.amoeba.sqljep.function;
import com.meidusa.amoeba.sqljep.function.PostfixCommand;
import com.meidusa.amoeba.sqljep.ASTFunNode;
import com.meidusa.amoeba.sqljep.JepRuntime;
import com.meidusa.amoeba.sqljep.ParseException;
public class Lpad extends PostfixCommand {
private static final String PARAM_EXCEPTION = "Length in lpad shoud be integer";
final public int getNumberOfParameters() {
return -1;
}
public Comparable<?>[] evaluate(ASTFunNode node, JepRuntime runtime) throws ParseException {
node.childrenAccept(runtime.ev, null);
int num = node.jjtGetNumChildren();
if (num == 2) {
Comparable<?> param2 = runtime.stack.pop();
Comparable<?> param1 = runtime.stack.pop();
return new Comparable<?>[]{param1,param2," "};
}
else if (num == 3) {
Comparable<?> param3 = runtime.stack.pop();
Comparable<?> param2 = runtime.stack.pop();
Comparable<?> param1 = runtime.stack.pop();
return new Comparable<?>[]{param1,param2,param3};
} else {
// remove all parameters from stack and push null
removeParams(runtime.stack, num);
throw new ParseException(PARAMS_NUMBER+" for lpad");
}
}
public static String lpad(Comparable<?> param1, Comparable<?> param2, Comparable<?> param3) throws ParseException {
if (param1 == null || param2 == null || param3 == null) {
return null;
}
String inputStr = param1.toString();
String chars = param3.toString();
int length;
try {
length = getInteger(param2);
} catch (ParseException e) {
throw new ParseException(PARAM_EXCEPTION);
}
if (length == inputStr.length()) {
return inputStr;
}
else if (length < inputStr.length()) {
return inputStr.substring(0, length);
} else {
length -= inputStr.length();
int count = length / chars.length();
int remainder = length % chars.length();
StringBuilder output = new StringBuilder();
for (int i = 0; i < count; i++) {
output.append(chars);
}
output.append(chars.substring(0, remainder));
output.append(inputStr);
return output.toString();
}
}
public Comparable<?> getResult(Comparable<?>... comparables)
throws ParseException {
return lpad(comparables[0],comparables[1],comparables[2]);
}
}