將Oracle數據庫與jdbc連接

Question

我正在嘗試一個程序來檢查下面與oracle數據庫的連接

import java.sql.*;  
class OracleCon{  
public static void main(String args[]){  
    try{  
        //step1 load the driver class  
        Class.forName("oracle.jdbc.driver.OracleDriver");  

        //step2 create  the connection object  
        Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","SangamOne123");  

        //step3 create the statement object  
        Statement stmt=con.createStatement();  

        //step4 execute query  
        ResultSet rs=stmt.executeQuery("select * from emp");  
        while(rs.next())  {
            System.out.println(rs.getInt(1)+"  "+rs.getString(2)+"  "+rs.getString(3));  
        }

         //step5 close the connection object  
         con.close();  

        } catch(Exception e){
            System.out.println(e);
        }
    }  
}  

但是在eclipse中運行它之后，它顯示以下異常。

java.sql.SQLException：偵聽器拒絕連接，並出現以下錯誤：ORA-12505，TNS：listener當前不知道連接描述符中給出的SID

請幫助我，我是oracle數據庫的新手。

Answer 1

問題與oracle的SID (System Identifier)有關，在安裝oracle或創建數據庫時會創建SID。

確保您的SID是xe並已配置為使用偵聽器。

還要在oracle安裝中簽出listener.ora文件。 它看起來應該如下所示：

 SID_LIST_LISTENER =
    (SID_LIST =
        (SID_DESC =
          (SID_NAME = default)
          (ORACLE_HOME = C:\app\oracle\product\11.2.0\dbhome_1)
          (PROGRAM = extproc)
          (ENVS = "EXTPROC_DLLS=ONLY:C:\app\oracle\product\11.2.0\dbhome_1\bin\oraclr11.dll")
        )

       (SID_DESC =
         (GLOBAL_DBNAME = ORCL)
         (ORACLE_HOME = C:\app\oracle\product\11.2.0\dbhome_1)
         (SID_NAME = orcl)
        )

       (SID_DESC =
         (GLOBAL_DBNAME = BMBK)
         (ORACLE_HOME = C:\app\oracle\product\11.2.0\dbhome_1)
         (SID_NAME = BMBK)
        )

     )

    LISTENER =
      (DESCRIPTION_LIST =
        (DESCRIPTION =
          (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
          (ADDRESS = (PROTOCOL = TCP)(HOST = 123.456.789.101)(PORT = 1521))
          (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
        )
      )

請注意第三行，其中SID_NAME = default ，對於您的偵聽器， SID應該為xe或使用此處指定的任何內容。

您的系統中可能還會有多個SID。