假如传来一个参数：Map<String,String> m
if (m != null) {
for (String k : m.keySet()) {
if (m.get(k) == null) {
where = where + " " + k + " is null and";
} else
where = where + " " + k + "='" + m.get(k) + "' and";
}
if (where != null && !where.equals("") && where.indexOf("and") > -1) {
where = where.substring(0, where.length() - 3);
where = "where " + where;
}
}
