javascript - 处理JSP页面时发生异常 - 类型异常报告

Question

我正在使用 PreparedStatement 运行以下代码。

<%
Class.forName("com.mysql.jdbc.Driver");
Connection Con=DriverManager.getConnection("jdbc:mysql://localhost:3306/onlineshopping","root","2710");
out.println("connection success full");%>
<%String username=request.getParameter("user_name");
String password=request.getParameter("password");
String cpassword=request.getParameter("cpassword");
String emailid=request.getParameter("email_id");
String address=request.getParameter("address");
String city=request.getParameter("city");
String pincode=request.getParameter("pincode");
String country=request.getParameter("country");
 PreparedStatement pst = null;
 if(password.equals(cpassword))
     {
    String str= "insert into register(user_name,password,email_id,address,city,pin,country) values(?,?,?,?,?,?,?)";
pst = Con.prepareStatement(str);
pst.setString(1,username);
pst.setString(2,password);
pst.setString(3,emailid);
pst.setString(4,address);
pst.setString(5,city);
pst.setString(6,pincode);
pst.setString(7,country);
int i = pst.executeUpdate();
String str1="insert into login(user_name,password) values (?,?)";
pst=Con.prepareStatement(str1);
pst.setString(1,username);
pst.setString(2,password);
int j=pst.executeUpdate();
if(i==0||j==0)
    {

    response.sendRedirect("registerError.jsp");
    }
else
    {
     HttpSession ses=request.getSession(true);
    session.setAttribute("user_name",username);
    response.sendRedirect("loggedIn.jsp");
}
}

%>

但是，它会生成以下错误消息:

type Exception report

message An exception occurred processing JSP page /register.jsp at line 35

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /register.jsp at line 35

32: pst.setString(5,city);
33: pst.setString(6,pincode);
34: pst.setString(7,country);
35: int i = pst.executeUpdate();
36: String str1="insert into login(user_name,password) values (?,?)";
37: pst=Con.prepareStatement(str1);
38: pst.setString(1,username);


Stacktrace:
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:575)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:462)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

javax.servlet.ServletException: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'user_name' cannot be null
    org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:916)
    org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:845)
    org.apache.jsp.register_jsp._jspService(register_jsp.java:125)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'user_name' cannot be null
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:408)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    com.mysql.jdbc.Util.getInstance(Util.java:384)
    com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1041)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3566)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3498)
    com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
    com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2113)
    com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
    com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2113)
    com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2409)
    com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2327)
    com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2312)
    org.apache.jsp.register_jsp._jspService(register_jsp.java:94)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.63 logs.

我做错了什么？

Answer 1

错误在于您的帖子本身..异常:com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException，并显示消息列“user_name”不能为空。请检查user_name字段是否为空。