连接数据库出错 之前的可以换过一个数据库就不行了 请高手帮下

Question

连接数据库出错 之前的可以换过一个数据库就不行了，我之前的是用MySQL 后面我换SQL2005的就不行了 我驱动也是导入sqljdbc4.jar 的 
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); // 连接SQL2005
  conn = DriverManager.getConnection("jdbc:jtds:sqlserver://localhost:1433/bbs","sa","123456");
我报错是  ：
type Exception reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:500)
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
hl.hlg.bbs.DB.createStmt(DB.java:31)
org.apache.jsp.articleFlat_jsp._jspService(articleFlat_jsp.java:104)
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)note The full stack trace of the root cause is available in the Apache Tomcat/6.0.30 logs.
改回原来的驱动连接就行了 
// Class.forName("com.mysql.jdbc.Driver");     // 连接MySQL
 // conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs", "root", "root");请高手帮帮忙~ 

Answer 1

嘿嘿  你试试  把sqljdbc4.jar 复制到 你项目的 WEB-INF 下的 lib  里 然后 刷新项目  再试试还报错就不知道了  嘿嘿嘿

Answer 2

conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=bbs","root","root");

Answer 3

配置数据源了吗？sqlserver貌似要配数据源...

Answer 4

java.lang.NullPointerExceptionhl.hlg.bbs.DB.createStmt(DB.java:31)取connection没取到，导致conn.createStatement()空指针也就是说，DriveManager.getConnection()这里面就出错了，或取不到连接！

Answer 5

修改一下这句试试conn = DriverManager.getConnection("jdbc:jtds:sqlserver://localhost:1433/bbs","sa","123456");改为：conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databasename=你得数据库名字","sa","123456");

Answer 6

改为
conn =DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=bbs","sa","123456");还是出这样的错误
type Exception reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:500)
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.articleFlat_jsp._jspService(articleFlat_jsp.java:123)
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)