执行preparedStatement类时出错？各位仁兄请帮帮忙！

public boolean insertValue(String a,String b,String c,String d){
boolean succ = false;
java.sql.Connection conn = null;
java.sql.PreparedStatement ps = null;
try{
String sql = "INSERT INTO TABLENAME(F1,F2,F3,F4,F5) VALUES(?,?,?,?,?)";
conn = pDataSource.getConnection();
ps = conn.prepareStatement(sql);
javax.sql.RowSet rsTmp = getRowSet(a,b,c,d);
rsTmp.beforeFirst();
while(rsTmp.next()){
String tmp3= rsTmp.getString("F3");
String tmp4= rsTmp.getString("F4");
String tmp5= rsTmp.getString("F5");
double douTmp = 0;
ps.setString(1,A);//执行到此处时出错
ps.setString(2,B);
ps.setString(3,tmp3);
ps.setString(4,tmp4);
ps.setString(5,tmp5);
ps.executeUpdate();
}
.....