后台的错误提示:
java.lang.NullPointerException
at testweb.TestDB.selectinfo(TestDB.java:42)
at jsp_servlet.__test._jspService(__test.java:114)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:304)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:24
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
java.lang.NullPointerException
at jsp_servlet.__test._jspService(__test.java:115)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:304)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:24
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
java.lang.NullPointerException
at testweb.TestDB.selectinfo(TestDB.java:42)
at jsp_servlet.__test._jspService(__test.java:114)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:304)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:24
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
java.lang.NullPointerException
at jsp_servlet.__test._jspService(__test.java:115)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:304)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:24
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
package testweb;import java.sql.*;
import javax.naming.*;
import javax.sql.*;
import java.util.*;
/**
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2003</p>
* <p>Company: </p>
* @author not attributable
* @version 1.0
*/public class TestDB {
public DataSource ds;
public Connection connection;
public ResultSet rs=null; public TestDB(){//建立一个数据源
try{
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
env.put(Context.SECURITY_PRINCIPAL,"system");
env.put(Context.SECURITY_CREDENTIALS,"system123");
Context context = new InitialContext(env);
DataSource ds = (DataSource) context.lookup("myDataSource");
}
catch( Exception e)
{
System.out.println("Error1");
e.printStackTrace();
return;
}
}
public ResultSet selectinfo (){
try{ connection = ds.getConnection();
Statement stmt = connection.createStatement();
rs = stmt.executeQuery("select * from usr where bm_usr='111'");
}
catch( Exception e)
{
System.out.println("Error2");
e.printStackTrace();
return null;
}
return rs;
}
}
试试行不行
改成
<jsp:useBean id="testbean" scope="page" class="testweb.TestDB"/>不行的话就改成
<%
testweb.TestDB testbean = new testweb.TestDB();
%>