String or StringBuffer

Question

private void doShareEmp(pageBean UTIL, HttpServletRequest request, String page)
        throws Exception
{
    doAction(request, UTIL, page);
    String action = pageBean.getSafeRequestOrNullParameter(request, "DO");
    long empRecNum = UTIL.getNumValue("EMPLOYEE", "REC_NUM");
    if (action != null)
    {
        if (action.startsWith("US:"))
            unshareEmployee(request, UTIL, action.substring(3));
        else if (action.equals("SHARE") && empRecNum != 0)
            shareEmployee(request, UTIL, empRecNum);
    }
    ListBean list = UTIL.getListBean(request, "EMPSHARELIST", true);
    if (empRecNum != 0)
    {
        StringBuffer sql = new StringBuffer();
        sql.append("SELECT FLDREC_NUM, FLDCOMPANY, FLDLOCATION, FLDDEPT FROM @SCHEMAEMPLVIEW WHERE FLDEMPLOYEE = ? AND FLDTABLE='SHARED' ORDER BY FLDCOMPANY, FLDLOCATION, FLDDEPT");
        ArrayList qryParms = new ArrayList();
        qryParms.add(new Long(empRecNum));
        list.setQuery(UTIL, sql, qryParms);
    }
    else
        list.init();
}

In this piece of code i am appending an query to a StringBuffer.

Which one will be better?

1. String
2. StringBuffer
3. StringBuilder

Answer 1

StringBuilder is a replacement to StringBuffer in a single threaded environment since 1.5, so go with StringBuilder. If you are not going to do any other manipulation with the data after the fact, go with String.

Answer 2

StringBuffer is only needed in threaded environment and if you need synchronization. Here it doesn't seem to be the case.

Also, your string seems defined one and for all, a simple String would be enough. A StringBuilder is interesting when you are modifying your "string" by appending content. If you already have all your content, no need for a StringBuilder.

But you can already read all these informations on their javadocs :

The StringBuilder class should generally be used in preference to this one, as it supports all of the same operations but it is faster, as it performs no synchronization.