网络适配器无法建立连接异常

Question

import java.beans.Statement;
import java.sql.Connection; 
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;


public class blehinternal {

    static final String JDBC_DRIVER = "oracle.jdbc.driver.OracleDriver";  
    static final String DB_URL = "jdbc:oracle:thin:@localhost:1521:xe";

    static final String USER = "username";
    static final String PASS = "password";

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Connection conn = null;
        java.sql.Statement stmt = null;
           try{
              //STEP 2: Register JDBC driver
              Class.forName("oracle.jdbc.driver.OracleDriver");

              //STEP 3: Open a connection
              System.out.println("Connecting to database...");
              conn = DriverManager.getConnection(DB_URL, USER, PASS);

              //STEP 4: Execute a query
              System.out.println("Creating database...");
              stmt = conn.createStatement();

              String sql = "CREATE DATABASE STUDENTS";
              stmt.executeUpdate(sql);
              System.out.println("Database created successfully...");
           }catch(SQLException se){
              //Handle errors for JDBC
              se.printStackTrace();
           }catch(Exception e){
              //Handle errors for Class.forName
              e.printStackTrace();
           }finally{
              //finally block used to close resources
              try{
                 if(stmt!=null)
                    stmt.close();
              }catch(SQLException se2){
              }// nothing we can do
              try{
                 if(conn!=null)
                    conn.close();
              }catch(SQLException se){
                 se.printStackTrace();
              }//end finally try
           }//end try
           System.out.println("Have A Nice Day");
        }//end main
        }//end example

我正在尝试从Java在本地创建我的第一个oracle数据库，我想在其中添加表并填充它们，但是我在第一步中遇到了问题，值得一提的是，我在尝试的其他地方都没有架构连接到代码中的内容是我所做的全部

我尝试了多个DB_URL，但它们似乎都不起作用，我在下面共享了一个例外，我将很高兴帮助您了解如何在本地创建该数据库，然后继续从Java创建表] >

Connecting to database...
java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
Have A Nice Day
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:673)
    at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:715)
    at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:385)
    at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:30)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:564)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at blehinternal.main(blehinternal.java:28)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
    at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:445)
    at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:464)
    at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:594)
    at oracle.net.ns.NSProtocol.connect(NSProtocol.java:229)
    at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1360)
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:486)
    ... 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:162)
    at oracle.net.nt.ConnOption.connect(ConnOption.java:133)
    at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:411)
    ... 12 more

import java.beans.Statement;导入java.sql.Connection;导入java.sql.DriverManager;导入java.sql.ResultSet;导入java.sql.ResultSetMetaData;导入java.sql.SQLException;公共类...

Answer 1

从您的回复看来，您所拥有的只是客户端库。您将需要安装Oracle数据库服务器，以使客户端可以连接到某些服务器。 Oracle XE是最简单的选择。