Help In Programming Needed.

Question

This is part of a program written in JSP using netbean.
<%
try {
String driver = "com.mysql.jdbc.Driver";
String database = "jdbc:mysql://localhost/crm";
Class.forName(driver);
System.out.println("Driver " + driver + " loaded.");
Connection connection = DriverManager.getConnection(database, "root", "123");
System.out.println("Database " + database + " loaded.");
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery("SELECT PASSWORD FROM USER WHERE STAFFID = \'" + logUser.getSTAFFID() + "\'");
resultSet.next();
if (logUser.getPASSWORD().equals(resultSet.getString(1))) {%>
<jsp:forward page="HomeLogIn.jsp" />
<% } else {%>
<jsp:forward page="LogInError.jsp" />
<% }
} catch (Exception ex) {
ex.printStackTrace();
} %>
And this is error that was produced when try to run it.
java.sql.SQLException: Illegal operation on empty result set.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:910)
at com.mysql.jdbc.ResultSet.checkRowPos(ResultSet.java:713)
at com.mysql.jdbc.ResultSet.getStringInternal(ResultSet.java:5624)
at com.mysql.jdbc.ResultSet.getString(ResultSet.java:5544)
at org.apache.jsp.Home_jsp._jspService(Home_jsp.java from :88)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:93)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:470)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:364)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:317)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:288)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:206)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:150)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:272)
at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:637)
at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:568)
at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:813)
at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
at com.sun.enterprise.web.portunif.PortUnificationPipeline$PUTask.doTask(PortUnificationPipeline.java:380)
at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
Can anyone tell me what's wrong with my program?

Answer 1

If you take a glance at the [API for ResultSet|http://java.sun.com/j2se/1.5.0/docs/api/java/sql/ResultSet.html#next()] you might notice that the rs.next() method returns a boolen value.
It returns true if there IS a next record, otherwise false.
Most people write code something like
if (rs.next()){
  // if only one result is expected
//or
while(rs.next()){
  // if multiple rows are expected.
}