无法连接Derby数据库：连接被拒绝

Question

我下载了示例Derby应用程序源代码。我在项目中添加了与Derby相关的所有罐子。不幸的是，当我运行应用程序时，我得到了很多异常堆它是什么原因？

java.sql.SQLNonTransientConnectionException: java.net.ConnectException: Błąd podczas łączenia z serwerem localhost na porcie 1,526 z komunikatem Connection refused: connect.
    at org.apache.derby.client.am.SQLExceptionFactory.getSQLException(Unknown Source)
    at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
    at org.apache.derby.jdbc.ClientDriver.connect(Unknown Source)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:270)
    at zad1.Restaurants.createConnection(Restaurants.java:33)
    at zad1.Restaurants.main(Restaurants.java:20)
Caused by: ERROR 08001: java.net.ConnectException: Błąd podczas łączenia z serwerem localhost na porcie 1,526 z komunikatem Connection refused: connect.
    at org.apache.derby.client.net.NetAgent.<init>(Unknown Source)
    at org.apache.derby.client.net.NetConnection.newAgent_(Unknown Source)
    at org.apache.derby.client.am.ClientConnection.<init>(Unknown Source)
    at org.apache.derby.client.net.NetConnection.<init>(Unknown Source)
    at org.apache.derby.client.net.ClientJDBCObjectFactoryImpl.newNetConnection(Unknown Source)
    ... 5 more
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at java.net.Socket.connect(Socket.java:538)
    at java.net.Socket.<init>(Socket.java:434)
    at java.net.Socket.<init>(Socket.java:211)
    at javax.net.DefaultSocketFactory.createSocket(SocketFactory.java:271)
    at org.apache.derby.client.net.OpenSocketAction.run(Unknown Source)
    at org.apache.derby.client.net.OpenSocketAction.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    ... 10 more
Exception in thread "main" java.lang.NullPointerException
    at zad1.Restaurants.insertRestaurants(Restaurants.java:45)
    at zad1.Restaurants.main(Restaurants.java:21)

我明白了：

LPTSTR