如何使用Java测试与Oracle数据库的连接

Question

有没有办法使用Java测试我与oracle数据库的连接？这是我的代码.

public class OracleConnection {

    public static void main(String[] args) throws Exception {
        //connect to database
        Class.forName("oracle.jdbc.driver.OracleDriver");
        String serverName = "00.000.0.000";
        String portNumber = "1521";
        String sid = "My Sid";
        String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;
        String username = "UNAME";
        String password = "PASSWORD";
        Connection conn = DriverManager.getConnection(url, username, password);
    }
}

我想要做的是测试数据库是否可以访问,如果不可以,那么程序将连接到下一个数据库.我有8个生产数据库.

Answer 1

DriverManager#getConnection它自己尝试建立与给定数据库URL的连接.DriverManager尝试从已注册的JDBC驱动程序集中选择适当的驱动程序.和Thorws SQLException如果发生数据库访问错误.

您可以测试连接是否有效,Connection#isValid(int timeout)如果连接尚未关闭且仍然有效,则返回true.

...
Connection conn = DriverManager.getConnection(url, username, password);
boolean reachable = conn.isValid(10);// 10 sec

Answer 2

用于检查与Oracle DB的连接的简单Java代码:

import java.sql.*;    
public class Test {
  private final static String DB_URL = "jdbc:oracle:thin:@//192.168.1.105:1521/MYORA";
  private final static String USER = "myuser";
  private final static String PASS = "mypwd";

  public static void main(String[] args) {
    Connection conn = null;  
    try {    
      Class.forName("oracle.jdbc.driver.OracleDriver");    
      System.out.println("Connecting to database...");    
      conn = DriverManager.getConnection(DB_URL,USER,PASS);    
    } catch (Exception e) {    
      e.printStackTrace();    
    } finally {    
      if (conn != null) {    
        try {    
          conn.close();    
        } catch (SQLException e) {    
          // ignore    
        }    
      }    
    }            
  }    
}

Answer 3

不要重新发明轮子.Oracle的JDBC驱动程序已经内置了此功能.

这很有用:http://www.orafaq.com/wiki/JDBC

import java.util.ArrayList;
import java.sql.*;

public class OracleConnection {

    public static void main(String[] args) throws Exception {
        //connect to database
        Class.forName("oracle.jdbc.driver.OracleDriver");
        ArrayList<String> serverNames = new ArrayList<String>();
        serverNames.add("yourhostname1");
        serverNames.add("yourhostname2");
        serverNames.add("yourhostname3");
        serverNames.add("yourhostname4");
        String portNumber = "1521";
        String sid = "ORCLSID";
        String url = "jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(LOAD_BALANCE=ON)(FAILOVER=ON)" ;
        for (String serverName : serverNames) {  
            url += "(ADDRESS=(PROTOCOL=tcp)(HOST="+serverName+")(PORT="+portNumber+"))";
        }
        url += ")(CONNECT_DATA=(SID="+sid+")))";
        String username = "USERNAME";
        String password = "PASSWORD";
        // System.out.println(url); // for debugging, if you want to see the url that was built
        Connection conn = DriverManager.getConnection(url, username, password);
    }
}

上面的代码实际上构建并使用看起来像这样的url(如下例所示).我通过取消注释代码末尾附近的调试行明确地得到了这个:

jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=
    (LOAD_BALANCE=ON)(FAILOVER=ON)
    (ADDRESS=(PROTOCOL=tcp)(HOST=yourhostname1)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=yourhostname2)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=yourhostname3)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=yourhostname4)(PORT=1521))
  )(CONNECT_DATA=(SID=ORCLSID)))