tomecat4连接池问题

Question

Csdn上多的很，你自己搜一下就有N多！

Answer 1

正好，我刚写了一段
给你： public Connection getPoolDataSource(String jndi)
{
Connection conn = null;
try
  {
  InitialContext itial = new InitialContext();
  DataSource ds = (DataSource)itial.lookup("java:comp/env/jdbc/"+jndi);
  conn = ds.getConnection();
  }
  catch(Exception er)
  {
  System.out.println("Exception in getPoolDataSource: " + er.toString());
  }
  return conn;
}

Answer 2

不用连接池时是这样做的吧:
Class.forName(...)
Connection conn = DriverManager.getConnection(....);
Statement stat = conn.createStatement();现在你就可以这样:
public Connection getPoolDataSource(String jndi)
{
Connection conn = null;
try
 {
 InitialContext itial = new InitialContext();
 DataSource ds = (DataSource)itial.lookup("java:comp/env/"+jndi);
 conn = ds.getConnection();
 }
 catch(Exception er)
 {
 System.out.println("Exception in getPoolDataSource: " + er.toString());
 }
 return conn;
}Connection con = getPoolDataSource("jdbc/mysql");
Statement stat = conn.createStatement();
...后面就一样了,
只是得到的数据源连接的方式不同"jdbc/mysql"是在tomcat为连接池配的JNDI名字

Answer 3

我原来的java代码是这样的：package online;
import java.sql.*;
public class onlineconn1
{
  String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
  String sConnStr = "jdbc:odbc:online";
  //String strUser = "sa";
  //String strPassword = "1978sx";
  Connection conn = null;
  public ResultSet rs = null;
  private java.sql.Statement stmt = null;
  public onlineconn1()
  {
    try {
           Class.forName(sDBDriver);
         }
    catch(java.lang.ClassNotFoundException e)
         {
           System.err.println("onlineconn1(): " + e.getMessage());
         }
  }
  public ResultSet executeQuery(String sql)
  {
     rs = null;
     try {
            conn = DriverManager.getConnection(sConnStr);
            Statement stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
          }
     catch(SQLException ex)
         {
            System.err.println("aq.executeQuery: " + ex.getMessage());
          }
     return rs;
  }
  public void executeUpdate(String sql)
  {
     try {
            conn = DriverManager.getConnection(sConnStr);
            Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
            stmt.executeUpdate(sql);
          }
     catch(SQLException ex)
         {
            System.err.println("aq.executeUpdate: " + ex.getMessage());
          }
  }
  public void disconnectToDB() throws
      java.sql.SQLException{
              
           if(rs!=null)
             {
                 rs.close();
                 rs = null;  
              }   
           
           if(stmt!=null){
                 stmt.close();
                 stmt = null;  
              }           if(conn!=null)
             {
                 conn.close();
                 conn = null;  
              } 
        }
}
然后jsp页面中这样调用:
<jsp:useBean id="workM" scope="page" class="online.onlineconn1" />String strSQL;
strSQL="select * from student where name='"+name1+"' and mkey='"+key1+"'";
try{
      workM.executeQuery(strSQL);
  if(!workM.rs.next()){
                      response.sendRedirect("stuloginerror.htm");
                              }
     else{ 
......
现在用连接池怎么改?
谢谢!

Answer 4

<jsp:useBean id="workM" scope="page" class="online.onlineconn1" />String strSQL;
strSQL="select * from student where name='"+name1+"' and mkey='"+key1+"'";
把上面的改成
<jsp:useBean id="workM" scope="page" class="online.onlineconn1" />String strSQL;
strSQL="select * from student where name='"+name1+"' and mkey='"+key1+"'";
Connection con=workM.getConnection();
PreparedStatement pre=con.preparedStatement(sql);
ResultSet res=pre.executeQuery();

Answer 5

改为连接池，我原来的java代码应如何改呢？谢谢！package online;
import java.sql.*;
public class onlineconn1
{
  String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
  String sConnStr = "jdbc:odbc:online";
  //String strUser = "sa";
  //String strPassword = "1978sx";
  Connection conn = null;
  public ResultSet rs = null;
  private java.sql.Statement stmt = null;
  public onlineconn1()
  {
    try {
           Class.forName(sDBDriver);
         }
    catch(java.lang.ClassNotFoundException e)
         {
           System.err.println("onlineconn1(): " + e.getMessage());
         }
  }
  public ResultSet executeQuery(String sql)
  {
     rs = null;
     try {
            conn = DriverManager.getConnection(sConnStr);
            Statement stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
          }
     catch(SQLException ex)
         {
            System.err.println("aq.executeQuery: " + ex.getMessage());
          }
     return rs;
  }
  public void executeUpdate(String sql)
  {
     try {
            conn = DriverManager.getConnection(sConnStr);
            Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
            stmt.executeUpdate(sql);
          }
     catch(SQLException ex)
         {
            System.err.println("aq.executeUpdate: " + ex.getMessage());
          }
  }
  public void disconnectToDB() throws
      java.sql.SQLException{
              
           if(rs!=null)
             {
                 rs.close();
                 rs = null;  
              }   
           
           if(stmt!=null){
                 stmt.close();
                 stmt = null;  
              }           if(conn!=null)
             {
                 conn.close();
                 conn = null;  
              } 
        }
}