毕设急求，200分全送 数据库连接问题

Question

书中的一个系统数据库连接有问题，小系统，只用了javabean.
连接sql sever2005数据库。配置了proxool.这个我完全不懂。悲剧。能找到的和数据库连接有关的代码我都贴下面了:
tomcat的conf文件夹下server.xml文件
      <Context path="/net" docBase="net" debug="5" reloadable="true" crossContext="true">
        <Resource name="jdbc/ConnectionPool"
            auth="Container"
            type="javax.sql.DataSource"
            maxActive="20"
            maxIdle="5"
            maxWait="10000"
            username="sa"
            password="123"
            driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"
            url="jdbc:sqlsever://localhost:1443;DatabaseName=db_net"/>
      </Context>
      
数据库连接的类
private static Connection cn = null; private void getConnection() {
if (cn != null) {
return;
}
Context ctx;
try {
ctx = new InitialContext();
DataSource ds = (DataSource) ctx
.lookup("java:comp/env/jdbc/ConnectionPool");
cn = ds.getConnection();
} catch (NamingException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} return;
}
proxool.propertities文件
jdbc-0.proxool.alias=net
jdbc-0.proxool.driver-class=com.microsoft.sqlserver.jdbc.SQLServerDriver
jdbc-0.proxool.driver-url=jdbc:sqlserver://localhost:1433;DatabaseName=db_netjdbc-0.user=sa
jdbc-0.password=123
jdbc-0.proxool.maximum-connection-count=10
jdbc-0.proxool.prototype-count=4jdbc-0.proxool.house-keeping-test-sql=select CURRENT_DATE
jdbc-0.proxool.verbose=true
jdbc-0.proxool.statistics=10s,1m,1d
jdbc-0.proxool.statistics-log-level=DEBUG
web-inf下的web.xml文件
  <resource-ref>
    <description>SQL server text app</description>
    <res-ref-name>jdbc/ConnectionPool</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
 </resource-ref>
在jsp中的调用：
try
{
con = DriverManager.getConnection("proxool.net");
stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
String query = "SELECT * FROM tb_usertable";
rs = stmt.executeQuery(query);

while(rs.next()) {
String name = rs.getString(2);
String password = rs.getString(3);
%>
姓名为：<%= name %><br>
密码为：<%=password %>
<%
}

stmt.close();
con.close();
}
运行时报错
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.microsoft.sqlsever.jdbc.SQLServerDriver'
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1136)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at com.wsy.connsqlserver.getConnection(connsqlserver.java:28)
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:40)
at com.wsy.selectsql.selectNews(selectsql.java:138)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
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 com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: com.microsoft.sqlsever.jdbc.SQLServerDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1130)
... 26 more
java.lang.NullPointerException
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:42)
at com.wsy.selectsql.selectNews(selectsql.java:138)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
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 com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
org.apache.jasper.JasperException: An exception occurred processing JSP page /index.jsp at line 4138: 
39:  <tr>
40:  <td colspan="2" rowspan="2" width="405" height="20"><table width="100%"  border="0"  background="images/17.gif" height="20">
41:           <%Collection temp2=sql.selectNews();
42:    Iterator it2=temp2.iterator();
43:    while(it2.hasNext()){
44:    news news=(news)it2.next();%>
Stacktrace:
at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at com.wsy.connsqlserver.close(connsqlserver.java:64)
at com.wsy.selectsql.selectNews(selectsql.java:154)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
... 18 more
求帮忙看看数据库连接哪里错了？

Answer 1

有没有放jar包！！！！楼主是一点都不懂 还是说懂一点啊？

Answer 2

: Cannot load JDBC driver class 'com.microsoft.sqlsever.jdbc.SQLServerDriver'
数据库驱动 有没有

Answer 3

下一个连接 sql2000的驱动包。。

Answer 4

貌似要sql2005的驱动包
地址：http://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=11774

Answer 5

楼主，你发的图片看不到。
看了你的问题，估计你jar包没加正确。不是简单的放入文件夹，还得在项目（buildpath）中引

Answer 6

哇，200分，我稀饭，包的问题，TMD微软就是这样，老是把驱动包改来改去，要不是没导驱动包，要不就是导错驱动包了,顺便接分ing

Answer 7

看提示 代码
Caused by: java.lang.ClassNotFoundException:com.microsoft.sqlsever.jdbc.SQLServerDrivercom.microsoft.sqlsever.jdbc.SQLServerDriver这个驱动包没有找到，新手百度下下载吧先解决驱动包问题，估计还会有其他问题

Answer 8

Caused by: java.lang.ClassNotFoundException:com.microsoft.sqlsever.jdbc.SQLServerDriver
写错了......

Answer 9

tomcat的conf文件夹下server.xml文件  driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"这里改一下吧。

Answer 10

楼主检查下 jar包有没有导入吧，还有楼上的说的那个问题 driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"
这里sqlsever写错了是sqlserver

Answer 11

显示错误为driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver" 这里sqlsever写错了是sqlserver,先改了这个再看能不能运行吧，错误都是这样一个一个解决的

Answer 12

在tomcat的webapps下lib包中加入2005的jar包

Answer 13

: Cannot load JDBC driver class 'com.microsoft.sqlsever.jdbc.SQLServerDriver'
数据库驱动jar包没有导进去，页面报那个也是因为这个 
导个驱动包就ok

Answer 14

driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"
  url="jdbc:sqlsever://localhost:1443;DatabaseName=db_net"/>
两个sqlserver都写错了，找得到才怪

Answer 15

没驱动包、将sqlserver2005的驱动包导入项目中 、应该就没有问题了。

Answer 16

将driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"
改为driverClassName="com.microsoft.sqlservler.jdbc.SQLServerDriver"，然后加入sqlserver的.jar驱动包

Answer 17

driverClassName="【你使用来连接数据库的驱动名】"
url="jdbc:sqlsever://localhost:1443;DatabaseName=【你的数据库名】"
如果你用的是MyEclipse，可以自己配置来获取driverClassName和url,如下：
window > Show View > Other > MyEclipse DataBase > DB Browser弹出"DB Browser视图"，然后右击 MyEclipse Derby > new ，此时弹出Database Driver窗体，
Driver template：选择Microsoft SQL （jTDS driver）
Driver name：随便你输入
Connection URL：<hostname>就是你数据库所在IP，如是本机就是localhost或127.0.0.1
                [:<port>]端口，一般是1433
                <dbname>你要连接的数据库名
User name:你访问的数据库用户名
Password：密码
在Driver JARs中按“Add JARs”选择你连接数据库的驱动
选择后Driver classname自动获取了
勾上上面的Save password点击“Test Driver" ，如弹出成功，则把Connection URL 和 Driver classname复制到你的tomcat中即可

Answer 18

csdn怎么有时候回复框的工具条会不显示啊。。郁闷

Answer 19

赶紧核对你的jar包，肯定是jar包的问题~

Answer 20

他的项目数据库的jar包应该有，可能是他的驱动名跟jar包根本就对不上

Answer 21

楼主续帖
谢谢各位指点。那个URL和className的拼写错误改过来了。不过还是有个问题问问各位
在数据库连接类中我用这段代码：
              try {
  cn = DriverManager.getConnection("proxool.net");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
能连接成功。
而用下面这段代码替换上面的代码时则报错：
                  Context ctx;
try {
ctx = new InitialContext();
DataSource ds = (DataSource) ctx
.lookup("java:comp/env/jdbc/ConnectionPool");
cn = ds.getConnection();


} catch (NamingException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
错误如下：
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (到主机  的 TCP/IP 连接失败。 java.net.ConnectException: Connection refused: connect)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1225)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at com.wsy.connsqlserver.getConnection(connsqlserver.java:30)
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:51)
at com.wsy.selectsql.selectNews(selectsql.java:138)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
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 com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: 到主机  的 TCP/IP 连接失败。 java.net.ConnectException: Connection refused: connect
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.loginWithoutFailover(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)
at org.apache.tomcat.dbcp.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1247)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1221)
... 26 more
java.lang.NullPointerException
at com.wsy.connsqlserver.executeQuery(connsqlserver.java:53)
at com.wsy.selectsql.selectNews(selectsql.java:138)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
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 com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
org.apache.jasper.JasperException: java.lang.NullPointerException
at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:491)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
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 com.wsy.Filter.ModifyCode.doFilter(ModifyCode.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at com.wsy.connsqlserver.close(connsqlserver.java:75)
at com.wsy.selectsql.selectNews(selectsql.java:154)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:107)
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:377)
... 18 more
好像是提示TCP/IP到主机的连接失败。我用telnet localhost:1443命令，提示：不能打开到主机的连接，在端口23：连接失败
我在SQL server2005配置中SQLExpress的协议TCP/IP已启用了。不知道为什么会连接失败？而用第一段代码运行又没问题。谁能告诉我这是为什么呢？？

Answer 22

[color=#FF0000]26楼很亮很亮，帮忙看下啦！！！[/color]

Answer 23

Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: 到主机 的 TCP/IP 连接失败。 java.net.ConnectException: Connection refused: connect你自己说的：
  telnet localhost:1443命令，提示：不能打开到主机的连接，在端口23：连接失败
这个命令打错了，应该是：
  telnet localhost 1443
测试下端口是否正常。另外，你说：
  而用第一段代码运行又没问题。
是指哪一段？

Answer 24

驱动包是不是没加进去了，还有加了驱动包，其实这些数据源的配置你完全可以封装成一个类，以后拿到哪都可以用。封转类百度一下到处都是，只要得到一个connection就行了……

Answer 25

楼主没有看到<Context path="/net" docBase="net" debug="5" reloadable="true" crossContext="true">
   <Resource name="jdbc/ConnectionPool"
   auth="Container"
   type="javax.sql.DataSource"
   maxActive="20"
   maxIdle="5"
   maxWait="10000"
   username="sa"
   password="123"
   driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"
   url="jdbc:sqlsever://localhost:1443;DatabaseName=db_net"/>
   </Context>
中的driverClassName="com.microsoft.sqlsever.jdbc.SQLServerDriver"  
里面sqlserver被你写成了sqlsever么？少了一个字母。那么肯定找不到驱动了。