架构使用jsp+servlet+java+mysql
mysql里time字段类型为datetime
java实体类中该字段类型为Date
页面中，时间字段类型为空的信息显示不出来，且报错信息如下：
java.sql.SQLException: Value '0000-00-00 00:00:00' can not be represented as java.sql.Dateat com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1056)at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)at com.mysql.jdbc.ResultSet.getDateFromBytes(ResultSet.java:2304)at com.mysql.jdbc.ResultSet.getDate(ResultSet.java:2052)at com.mysql.jdbc.ResultSet.getDate(ResultSet.java:2015)at com.mysql.jdbc.ResultSet.getDate(ResultSet.java:2069)at dao.impl.DevicesDaoImpl.findAll(DevicesDaoImpl.java:26)at service.impl.DevicesServiceImpl.findAll(DevicesServiceImpl.java:20)at servlet.DevicesList.doGet(DevicesList.java:31)at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at filter.EncodingFilter.doFilter(EncodingFilter.java:29)
检查代码，并没有发现什么问题，只是因为这一条数据中，这个时间字段为空而已，而数据库中此字段是可以为空的
很显然，搜了一大堆没用的文章出来。也尝试改了很多。例如，在jsp页面<%=new SimpleDateFormat("yyyy-HH-mm").format(mobile.getMarketTime())%>
最终报错信息改成这样了：
java.lang.NullPointerExceptionat java.util.Calendar.setTime(Unknown Source)at java.text.SimpleDateFormat.format(Unknown Source)at java.text.SimpleDateFormat.format(Unknown Source)at java.text.DateFormat.format(Unknown Source)at org.apache.jsp.info_jsp._jspService(info_jsp.java:200)at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:747)at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:485)at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:410)at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:337)at servlet.DevicesList.doGet(DevicesList.java:33)
不放弃，继续找
http://blog.csdn.net/dczjzz/article/details/52446901 感谢作者，帮忙解决了问题，另外他出淤泥而不染，肯定是自己搞定的
解决了！
