Application: gvSIG desktop

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

import org.apache.commons.codec.binary.Base64;

import org.apache.commons.codec.binary.Hex;

import org.apache.commons.lang3.Range;

import static org.gvsig.expressionevaluator.ExpressionBuilder.FUNCTION_DECODE;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class DecodeFunction extends AbstractFunction {

    public DecodeFunction() {

        super(

            GROUP_CONVERSION, FUNCTION_DECODE, Range.is(2),

            "Decode binary data from textual representation in string.\nSupported formats are: base64, hex.",

            FUNCTION_DECODE+"({{data}}, 'hex')",

            new String[]{

                "data - A string value with the data to be converted",

                "format - A string value indicating the format of the input data. The default value is 'hex'."

            },

            "Byte array",

            true

        );

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

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

        String data_s = getStr(args,0);

        String type = getStr(args,1);

        if( "hex".equalsIgnoreCase(type) ) {

            byte[] data = Hex.decodeHex(data_s.toCharArray());

            return data;

        } else if( "base64".equalsIgnoreCase(type) ) {

            byte[] data = Base64.decodeBase64(data_s);

            return data;

        } else if( "escape".equalsIgnoreCase(type) ) {

            // Not supported

        }

        throw new IllegalArgumentException("Unsupported format type '"+type+"'.");

    }

}