org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 6 in the jsp file: /view.jsp
Generated servlet error:
con cannot be resolved
Generated servlet error:
con cannot be resolved
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<head><title></title></head>
<body>
<%@ page import="java.sql.*" %>
<%@ page contentType="text/html;charset=GB2312" %>
<%try
{
//注册数据库驱动程序为oracle驱动
Class.forName("oracle.jdbc.driver.OracleDriver");
}
catch (java.lang.ClassNotFoundException e)
{ System.err.println("mydb(): " + e.getMessage());
} String url="jdbc:oracle:thin:@localhost:1521:sun1";
Connection con=DriverManager.getConnection(url,"chat","chat");
Statement smt=con.createStatement();
ResultSet rs;
String sql;String errmsg=request.getParameter("errmsg");
if(errmsg!=null)
{
out.print("<font color=red size=5>"+errmsg+"</font>");
}
else
{
String nick,sex,color,time,note;
String refresh=(String)session.getValue("change");
if(!refresh.equals("0"))
response.setHeader("Refresh",refresh);
sql="select * from chatroom order by id";
rs=smt.executeQuery(sql);
while(rs.next())
{
nick=rs.getString(1);
sex=rs.getString(2);
color=rs.getString(3);
time=rs.getString(4);
note=rs.getString(5);
out.print(time+"><font color="+color+">"+nick+"说："+note+"</font><img src="+sex+"><br>");
}
}smt.close();
rs.close();%></body>
</html>错误变成:
HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 6 in the jsp file: /view.jsp
Generated servlet error:
The local variable rs may not have been initialized
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:84)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:328)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:397)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:288)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:267)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:255)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:556)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:293)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.9 logs.
ResultSet.CONCUR_UPDATABLE);
ResultSet rs;这个在if之前啥
在else中的rs=smt.executeQuery(sql);这句话才是为rs赋值。也就是说初始化。只有在初始化这个之后才可以执行close()这个方法。不然就会提示未初始化The local variable rs may not have been initialized