使用JDBC连接oracle数据库时好时坏?

Question

package test;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;public class Test{
public static void main(String args[]){
 Connection connection=null;
         Statement statement=null;
         ResultSet resultSet=null;
         String driver ="oracle.jdbc.OracleDriver";
         String url ="jdbc:oracle:thin:@(description=(address_list= (address=(host=10.3.15.67)(protocol=tcp)(port=1521))(address=(host=10.3.15.68)(protocol=tcp)(port=1521))(load_balance=yes)(failover=yes))(connect_data=(service_name= yzpp)))";
         String username = "yzpp"; 
         String password = "yzpp";
         try{
              Class.forName(driver);
              connection=DriverManager.getConnection(url,username,password);
              if(connection!=null)
                  System.out.println("success");
              statement=connection.createStatement();
              resultSet=statement.executeQuery("select count(*) from t_pub_ppml where n_ppdh in (select n_ppdh from T_FPKC_JGKC where N_JGDM=2500 and N_LLSL>0) --5775");
              while(resultSet.next()){
                 System.out.println(resultSet.getString(1)+"  "+resultSet.getString(1));
              }
              resultSet.close();
              statement.close();
              connection.close();
         }catch(Exception e){
          e.printStackTrace();
         }
    }
}
隔三岔五的连接失败：测试数据库连接开始*******开始进行连接********
连接数据库不成功！
java.sql.SQLException: The Network Adapter could not establish the connection
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:450)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:534)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:217)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:28)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:527)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.copote.zgs.ypxx.dao.util.DBUtil.getConn(DBUtil.java:24)
at com.copote.zgs.ypxx.dao.util.DBUtil.main(DBUtil.java:38)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:355)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:418)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:810)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:374)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1406)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:327)
... 8 more
Caused by: java.net.UnknownHostException: STAMPDBS: STAMPDBS
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:110)
at oracle.net.nt.ConnOption.connect(ConnOption.java:119)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:333)
... 13 more
java.lang.NullPointerException
at com.copote.zgs.ypxx.dao.util.DBUtil.main(DBUtil.java:38)我机器上装的jdk1.5
oracle 驱动包是ojdbc5_g.jar
我使用oracle10g.jar也是一样隔三岔五的连接失败,这是为什么啊？？

Answer 1

Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection 
Caused by: java.net.UnknownHostException: STAMPDBS: STAMPDBS 是本机的数据库么，如果是本地，换成localhost多试试，如果不是，检查一下网络状况。或者把这个host和ip配置到里的hosts文件里再试试。用ojdbc14.jar试试。