StringConverterFixer.java

package de.jpaw.bonaparte.converter;

import de.jpaw.bonaparte.pojos.meta.AlphanumericElementaryDataItem;

/** Sample implementation of StringConverter interface which performs several fixes on the data. */
public class StringConverterFixer extends DataConverterAbstract<String,AlphanumericElementaryDataItem> {

    private final boolean doTrimAll;
    private final boolean doTruncateAll;
    private final boolean doEmptyToNull;

    public StringConverterFixer(boolean doEmptyToNull, boolean doTruncateAll, boolean doTrimAll) {
        this.doTrimAll = doTrimAll;
        this.doTruncateAll = doTruncateAll;
        this.doEmptyToNull = doEmptyToNull;
    }

    @Override
    public String convert(String s, final AlphanumericElementaryDataItem meta) {
        if (s == null)
            return null;

        // step 1: trim if required or desired
        if (doTrimAll || meta.getDoTrim())
            s = s.trim();

        // step 2: truncate if required or desired and still too long
        if ((doTruncateAll || meta.getDoTruncate()) && s.length() > meta.getLength()) {
            s = s.substring(0, meta.getLength());
            // this may result in a new string which does have trailing space again, so repeat the trim?
            if (doTrimAll || meta.getDoTrim())
                s = s.trim();
        }

        // step 3: replace empty strings by null, if desired
        if (doEmptyToNull && s.length() == 0)
            return null;
        else
            return s;
    }

}