今天在客户那里发现一个很是诡异的问题：
    登录web项目后，进行登录，系统立即报错，报错如下：
java.sql.SQLException:ORA-01017:invalid username/password:logon denied
      at oracle.jdbc.dbaccess.DBEroor.throwSqlException(DBError.java:134)
      at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:289)
      at oracle.jdbc.ttc7.03log.receive2nd(03log.java:496)
      at oracle.jdbc.ttc7.TTC7Protocol.logon(TTC7Protocol.java:278)
      at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:346)
      at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:468)
      at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
      at java.sql.DriverManager.getConnection(DriverManager.java:512)
      at java.sql.DriverManager.getConnection(DriverManager.java:171)
      at **.datasource.ConnectionPool.createConnectionSlit(ConnectionPool.java:295)
      at **.datasource.ConnectionPool.getConnection(ConnectionPool.java:358)
      at **.datasource.DataSourceUtils.getConnection(DataSourceUntils.java:386)
      at **.query.Pagination.getResultSet(Pagination.java:218)
      at **.jsp.index_jsp._jspService(index_jsp.java:296)
后面出现自己定义的报错：Failed to create new connection.,maybe due to the limitation of resource!
接着：java.sql.SQLException:Get ConnectionPool fail.null
      at **.datasource.ConnectionPool.createConnectionSlit(ConnectionPool.java:295)
      at **.datasource.ConnectionPool.getConnection(ConnectionPool.java:358)
      at **.datasource.DataSourceUtils.getConnection(DataSourceUntils.java:386)
      at **.query.Pagination.getResultSet(Pagination.java:218)
      at **.jsp.index_jsp._jspService(index_jsp.java:296)
其实提示的原因很明显，就是说我在ConnectionPool.java第295行利用在该java文件中定义好的用户名和密码去创建连接时，提示连接失败。
我解决方法如下：
(1)首先确认了该用户名和密码无误，因为自从系统部署后没有更改过任何属性配置文件；
(2)先将web项目所在的服务器进行了tomcat的重启；重启后依旧；
(3)怀疑oracle服务器down掉了，于是用oracle的Enterprise Manager Console,用该用户也能登录上。
由于没有配置PL/SQL工具，而且该数据库为私密数据，因此没有用ConnectionPool.java配置的用户名和密码进行登录，不知道有没有影响
网上也查了一些内容，但是感觉都帮助不大，希望各位大大能给我出出主意，该项目星期一要继续使用，时间紧迫啊，谢谢各位！

上面涉及函数语句如下：
ConnectionPool.java
        private String jdbcDriver = "oracle.jdbc.driver.OracleDriver"; 
private String jdbcUrl = "jdbc:oracle:thin:@serverIP:1521:ora81";
private String user = "admin"; // "root";
private String password = "1234"; // "";
        private ConnectionSlit createConnectionSlit() {
try {
ConnectionSlit slit = new ConnectionSlit();
slit.connection = DriverManager.getConnection(jdbcUrl, user,
password);
slit.used = false;
slit.start = 0;
slit.time = 0;
return slit;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}

        public Connection getConnection() {
        Thread thread = Thread.currentThread();
        String dumpString = "";
        if (dumpStackTrace) {
            System.out.println("Thread: " + thread
                    + " is requesting connection!");
            try {
                throw new Exception("thread dump");
            } catch (Exception e) {
                ExceptionSerializer es = new ExceptionSerializer(e);
                dumpString = es.serialize();
            }
        }
        synchronized (pools) {
            while (true) {
                ConnectionSlit slit = findFreeSlit();
                if (slit != null) {
                    slit.start = System.currentTimeMillis();
                    slit.used = true;
                    slit.thread = thread;
                    slit.dumpStack = dumpString;
                    return slit.connection;
                } else {
                    if (MAX_SIZE != 0 && pools.size() == MAX_SIZE) {
                        try {
                            System.out
                                    .println("waiting for connection to be freed...");
                            pools.wait();
                        } catch (InterruptedException ie) {
                        }
                    } else {
                       slit = [color=red]createConnectionSlit();
                        if (slit == null) {
                            System.err
                                    .println("Failed to create new connection, maybe due to the limitation of resource!");[/color]
                            return null;
                        }
                        slit.start = System.currentTimeMillis();
                        slit.used = true;
                        slit.thread = thread;
                        slit.dumpStack = dumpString;
                        pools.addElement(slit);
                        return slit.connection;
                    }
                }
            }
        }
    }

    DataSourceUntils.java
    public Connection getConnection() throws SQLException {
    Connection conn = null;
    ConnectionPool cp=ConnectionPool.getConnectionPool(datasource);
    try {
      if (cp != null) {
        cp = ConnectionPool.getConnectionPool(datasource);
        conn = cp.getConnection();
        conn.setAutoCommit(true);
        //System.out.println(datasource+" after get and count is "+cp.getConnectionCount());
        return conn;
      }
    }
    catch (Exception ne) {
      throw new SQLException("Get ConnectionPool fail." + ne.getMessage());
    }
    return conn;
  }

  Pagination.java
  DataSourceUtils dbu1 = new DataSourceUtils("zzz");
  Connection conn1 = null;
    try {

      try {
        PreparedStatement stmt1;

       ResultSet rs1;
        conn1 = dbu1.getConnection();
        stmt1 = conn1.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE,
                                       ResultSet.CONCUR_READ_ONLY);
        rs1 = stmt1.executeQuery();
        rs1.last();
        totalRows = rs1.getRow();