web 展现帖子详细内容出错


<%@page language="java" import="java.sql.*,bbs.*,java.util.*" pageEncoding="UTF-8"%><%
String strId = request.getParameter("id");
//System.out.println(strId);
if (strId == null || strId.trim().equals("")) {
out.print("Error ID!");
return;
}
int id = 0;
try {
id = Integer.parseInt(strId);
} catch (NumberFormatException e) {
out.println("Error ID Again!");
return;
}
List<Article> articles = new ArrayList<Article>();
Connection conn = DB.getConn();
String sql = "select * from article where rootid=" + id + "order by pdate asc";
Statement stmt = DB.createStmt(conn);
ResultSet rs = DB.executeQuery(stmt, sql);
while(rs.next()){
Article a = new Article();
a.initFromRs(rs);
articles.add(a);
}
//System.out.println(articles.size());
DB.close(stmt);
DB.close(rs);
DB.close(conn);
%>
报错
org.apache.jasper.JasperException: An exception occurred processing JSP page /articleDetailFlat.jsp at line 2219:  String sql = "select * from article where rootid=" + id + "order by pdate asc";
20:  Statement stmt = DB.createStmt(conn);
21:  ResultSet rs = DB.executeQuery(stmt, sql);
22:  while(rs.next()){
23:  Article a = new Article();
24:  a.initFromRs(rs);
25:  articles.add(a);
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:519)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:428)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root causejava.lang.NullPointerException
org.apache.jsp.articleDetailFlat_jsp._jspService(articleDetailFlat_jsp.java:77)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
--------------------
后台错误
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'by pdate asc' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)
at com.mysql.jdbc.Util.getInstance(Util.java:382)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3603)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3535)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1989)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2150)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2620)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2570)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1476)
at bbs.DB.executeQuery(DB.java:36)
at org.apache.jsp.articleDetailFlat_jsp._jspService(articleDetailFlat_jsp.java:76)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
七月 18, 2012 9:38:44 上午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.articleDetailFlat_jsp._jspService(articleDetailFlat_jsp.java:77)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)刚开始用的oracle都能显示出来，昨天换成了mysql一样的代码怎么就不行了哇...