Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.string;

import org.apache.commons.lang3.Range;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class MidFunction extends AbstractFunction {

    public MidFunction() {

        super("String", "MID", Range.between(2, 3));

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        String value;

        String str = getStr(args,0);

        int start = getInt(args, 1);

        switch(args.length) {

            case 2:

                value = StringUtils.substring(str, start);

                return value;

            case 3:

                int len = getInt(args, 2);

                value = StringUtils.mid(str, start, len);

                return value;

        }

        throw new ExpressionRuntimeException("Incorrect arguments number");

    }

}