无法连接到oracle数据库

Question

我正在尝试在eclipse中使用java连接到oracle数据库12c。这是一个不断被抓住的例外

Exception in thread "main" java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:743)
    at oracle.jdbc.driver.PhysicalConnection.connect(PhysicalConnection.java:666)
    at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:566)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at DBHelper.makeConnection(DBHelper.java:31)
    at Main.main(Main.java:37)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
    at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:470)
    at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:506)
    at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:595)
    at oracle.net.ns.NSProtocolStream.negotiateConnection(NSProtocolStream.java:246)
    at oracle.net.ns.NSProtocol.connect(NSProtocol.java:264)
    at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1452)
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:496)
    ... 7 more
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:161)
    at oracle.net.nt.ConnOption.connect(ConnOption.java:159)
    at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:428)
    ... 13 more

以下是我所做的

main.java

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Main {
  public static void main(String[] arg) throws SQLException{
        DBHelper dbconn = new DBHelper("system", "reborn78");
        Connection conn = dbconn.makeConnection();

        ResultSet result = dbconn.runQuery(conn, "SELECT A,B FROM NEWS");
        System.out.println(result);
  }
}

DBHelper.java

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class DBHelper {
    private String userName;
    private String passWord;
    private final String url = "jdbc:oracle:thin:@localhost:1521/ORCL"; 
    public DBHelper(String userName, String passWord) throws SQLException{
        Driver myDriver = new oracle.jdbc.driver.OracleDriver();
        DriverManager.registerDriver( myDriver );
        this.userName = userName;
        this.passWord = passWord;     
    }

    public Connection makeConnection() throws SQLException{
          Properties props = new Properties();
          props.setProperty("user", this.userName);
          props.setProperty("password", this.passWord);

          return DriverManager.getConnection(this.url,props);


    }
    public ResultSet runQuery(Connection conn, String sqlQuery) throws SQLException{
        PreparedStatement preStatement;     
        ResultSet result;
            Statement statement = conn.createStatement();
            preStatement = conn.prepareStatement(sqlQuery);
            statement.execute(sqlQuery);
            result = preStatement.executeQuery();
            return result;

    }
}

下面是我的listener.ora文件

# listener.ora Network Configuration File: E:appUsamaproduct12.1.0dbhome_1NETWORKADMINlistener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = E:appUsamaproduct12.1.0dbhome_1)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:E:appUsamaproduct12.1.0dbhome_1binoraclr12.dll")
    )
  )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
  )

下面是我的tnsnames.ora文件

# tnsnames.ora Network Configuration File: E:appUsamaproduct12.1.0dbhome_1NETWORKADMINtnsnames.ora
# Generated by Oracle configuration tools.
LISTENER_ORCL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))

ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )
ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

SQL使用sqlplus连接，侦听器运行并连接到SQL开发人员！下面是图片链接https://www.dropbox.com/sh/vbv0gkfcz2g59t5/AACtIVR1-bIen99DNN4HDsWaa?dl=0

我浪费了三天的时间来纠正这个问题，昨天我可以让它正常工作，但今天当我重新启动系统时，同样的错误又回来了。我已经尝试了所有可用的东西，但今天似乎都不起作用。提前感谢

Answer 1

已解决。

我可以通过使用数据库配置助手重新配置数据库，然后通过网络配置助手配置网络服务来运行它。

事实证明，据我所知，这是启动通过侦听器连接所需服务的唯一方法。每次重新启动系统时，我都必须手动完成并在网络配置助手中测试网络连接。

感谢您的支持。