java使用jsp dao和servlet从数据库中的4行中只插入几行
我有一个名为activitylog的数据库表，其中包含empid、日期、卡号、开始时间和结束时间
我只想在mysql数据库中插入不为空的几行
我知道如何一次插入一行或所有行，但我只想插入几行。请告诉我怎么做
索引。jsp
<form action="ActivityServlet" method="post">
<h2>ACTIVITY LOG</h2><br>
<table border="1" id="t01"><thead class="ui-widget-header">
<tr><th>Employee ID</th><th>Date</th><th>CRO/Job Card No.</th><th>Start Time</th><th>End Time</th><th>Category</th></tr>
</thead>
<tbody class="ui-widget-content">
<tr>
<td><input type="text" name="empid1" value=""/></td>
<td><input type="date" class="date" name="activitydate1"/></td>
<td><input type="text" name="cardno1" /></td>
<td><input type="time" name="starttime1"/></td>
<td><input type="time" name="endtime1"/></td>
<td><input type="text" name="category1"/></td>
</tr>
<tr>
<td><input type="text" name="empid2" value=""/></td>
<td><input type="date" class="date" name="activitydate2"/></td>
<td><input type="text" name="cardno2" /></td>
<td><input type="time" name="starttime2"/></td>
<td><input type="time" name="endtime2"/></td>
<td><input type="text" name="category2"/></td>
</tr>
<tr>
<td><input type="text" name="empid3" value=""/></td>
<td><input type="date" class="date" name="activitydate3"/></td>
<td><input type="text" name="cardno3" /></td>
<td><input type="time" name="starttime3"/></td>
<td><input type="time" name="endtime3"/></td>
<td><input type="text" name="category3"/></td>
</tr>
<tr>
<td><input type="text" name="empid4" value=""/></td>
<td><input type="date" class="date" name="activitydate4"/></td>
<td><input type="text" name="cardno4" /></td>
<td><input type="time" name="starttime4"/></td>
<td><input type="time" name="endtime4"/></td>
<td><input type="text" name="category4"/></td>
</tr>
</tbody>
</table>
<br><br>
<input class="myButton" type="submit" value="Submit">
<a href="logout.jsp" class="myButton">Logout</a>
</form>
活动DAO：
import com.eis.bean.ActivityBean;
import com.eis.bean.ConnectionProvider;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.List;
import java.sql.*;
public class ActivityDao {
public static final String sql= "insert into activitylog values(?,?,?,?,?,?,?,?,?)";
public static int activity(List<ActivityBean> ebList) throws Exception {
int i[] = null;
PreparedStatement ps=null;
System.out.println("In TimesheetDao");
Connection conn=ConnectionProvider.getConn();
ps = conn.prepareStatement(sql);
try{
System.out.println(" in try in Timesheetdao");
conn.setAutoCommit(false);
for (ActivityBean activitylog: ebList){
ps.setString(1,activitylog.getEmpid());
ps.setDate(2,new Date(activitylog.getActivitydate().getTime()));
ps.setString(3,activitylog.getCardno());
ps.setString(4,activitylog.getStarttime());
ps.setString(5,activitylog.getEndtime());
ps.setString(6,activitylog.getCategory());
ps.setString(7,activitylog.getActivity());
ps.setString(8,activitylog.getTraveltime());
ps.setString(9,activitylog.getRepairtime());
ps.addBatch();
}
i= ps.executeBatch();
conn.commit();
}
catch (SQLException e) {
System.out.println(e.getMessage());
conn.rollback();
}
finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
return i[0];
}
}
AvtivityServlet。爪哇
public class ActivityServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private ActivityDao dao;
public ActivityServlet() {
super();
dao = new ActivityDao();
}
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException,ParseException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
List<ActivityBean> ebList= new ArrayList<ActivityBean>();
for(int i=1;i<=4;i++){
ActivityBean ab = new ActivityBean();
ab.setEmpid(request.getParameter("empid"+i));
ab.setActivitydate((java.sql.Date) new java.sql.Date(formatter.parse(request.getParameter("activitydate"+i)).getTime()));
ab.setCardno(request.getParameter("cardno"+i));
ab.setStarttime(request.getParameter("starttime"+i));
ab.setEndtime(request.getParameter("endtime"+i));
ab.setCategory(request.getParameter("category"+i));
ab.setActivity(request.getParameter("activity"+i));
ab.setTraveltime(request.getParameter("traveltime"+i));
ab.setRepairtime(request.getParameter("repairtime"+i));
ebList.add(ab);
}
HttpSession session = request.getSession(false);
ActivityDao dao = new ActivityDao();
try {
int status = ActivityDao.activity(ebList);
if(status!=0){
out.print("<p style=\"color:Green\">Record saved successfully!!</p>");
RequestDispatcher rd=request.getRequestDispatcher("/index.jsp");
rd.include(request,response);
}
else{
out.print("<p style=\"color:red\">**Record cannot be saved!**</p>");
RequestDispatcher rd=request.getRequestDispatcher("/index.jsp");
rd.include(request,response);
}
}
catch(Exception e){
e.printStackTrace();
}
}
只有bean类在那里。 以上代码用于4行。将被插入到数据库中。但是我想知道如何只插入几行，例如2行或3行，那么我不能这样做。请帮帮我
错误：
17-Nov-2015 11:42:16.937 SEVERE [http-apr-8080-exec-145] com.eis.servlet.ActivityServlet.doPost null
java.text.ParseException: Unparseable date: ""
at java.text.DateFormat.parse(DateFormat.java:366)
at com.eis.servlet.ActivityServlet.processRequest(ActivityServlet.java:53)
at com.eis.servlet.ActivityServlet.doPost(ActivityServlet.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2503)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2492)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
# 1 楼答案
一种解决方案是检查DAO中的空值
例如：
在这里检查cardNo是否为空。您可以在那里进行各种检查，并根据您的条件限制插入的数量