jsp使用poolman连接mysql数据库的问题

Question

jsp使用poolman连接mysql数据库的问题，遇到下列问题：
我把代码贴出来：POOLMAN.XML
<?xml version="1.0" encoding="UTF-8"?><poolman>  <management-mode>local</management-mode> <datasource>    <dbname>default</dbname>
    <jndiName>jndi-default</jndiName>
    <driver>com.mysql.jdbc.Driver</driver>
    <url>jdbc:mysql://localhost:3306/hoteldb</url>
    <username>hotel</username>
    <password>123456</password>
    
    
    <minimumSize>5</minimumSize>
    <maximumSize>50</maximumSize>
    <connectionTimeout>2400</connectionTimeout>
    <userTimeout>600</userTimeout>
<logFile>E:/log/poolman.log</logFile>
<debugging>false</debugging>
    <shrinkBy>30</shrinkBy>    
<skimmerFrequency>300</skimmerFrequency> </datasource>
</poolman>
测试的JAVA类：
import com.codestudio.util.*; import java.io.File;
import java.sql.*; public class DbCtrl { 
      private static SQLManager sqlman;// = SQLManager.getInstance("C:/man.xml");       
      public DbCtrl(){ 
              if(sqlman == null){ 
                    sqlman = SQLManager.getInstance(); 
              } 
      }       public static Connection init(){ 
              Connection con = null; 
              try{ 
                    con = sqlman.requestConnection("default");                    
              }catch(Exception e){ 
                    e.printStackTrace(); 
              } 
              return con; 
      }     
      public static void main(String[] args) { 
              PreparedStatement pstmt = null; 
              Statement stmt = null; 
              ResultSet  rst = null; 
              Connection con = null;               DbCtrl cd2 = new DbCtrl(); 
              
              File f = new File("C:/man.xml"); 
              String s = f.getAbsolutePath(); 
              f.getName();
              System.out.println( f.getName()); 
 
              sqlman = SQLManager.getInstance("C:\\man.xml"); 
              if(sqlman == null)  
              {
                  System.out.println( "sqlman == null"); 
               return;
              }
              System.out.println( sqlman); 
              
              con=cd2.init(); 
              try{  
                    pstmt = con.prepareStatement("select * from users ");               }catch(Exception e ){ 
                    e.printStackTrace(); 
                    System.exit(0); 
              }      
              System.out.println("OK");       } 
  
} 在运行时遇到的问题：man.xml
com.codestudio.util.SQLManager@42719c** ERROR: Unable to find XML file C:\poolman.xml: java.lang.NullPointerException
java.sql.SQLException: No pool named default! Check your poolman.xml** DEBUG: If the StackTrace contains an InstanceAlreadyExistsException, then you have  encountered a ClassLoader linkage problem.  Please email [email protected] **
at com.codestudio.util.SQLManager.requestConnection(Unknown Source)
at DbCtrl.init(DbCtrl.java:19)
at DbCtrl.main(DbCtrl.java:48)
java.lang.NullPointerException
at DbCtrl.main(DbCtrl.java:50)
为什么会报这个错，一直没搞明白？