java - HSQL 连接错误。有什么见解吗？

Question

我正在尝试使用 java 连接到 HSQL。我正在使用一个教程来处理 JDBC 和 hibernate 。这是琳达教程。不管怎样，下面是代码:

package com.lynda.javatraining.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Main {

    private static final String USERNAME = "dbuser";
    private static final String PASSWORD = "dbpassword";
    private static final String CONN_STRING =
            "jdbc:hsqldb://data/explorecalifornia";

    public static void main(String[] args) throws SQLException {

        //Class.forName("com.mysql.jdbc.Driver");

        Connection conn = null;
        System.out.println("A");
        System.out.println(conn == null);
        System.out.println(CONN_STRING);
        try {
            System.out.println("B1");
            conn = DriverManager.getConnection(CONN_STRING, USERNAME, PASSWORD);
            System.out.println("B1-2");
            System.out.println("Connected!");
        } catch (SQLException e) {
            System.out.println("B2");
            System.err.println(e);
        } finally {
            System.out.println("B3");
            if (conn != null) {
                conn.close();
            }
        }
        System.out.println("C");

    }

}

这是我遇到的错误:

A
true
jdbc:hsqldb://data/explorecalifornia
B1
2014-06-27T15:26:27.430-0400  SEVERE  could not reopen database
org.hsqldb.HsqlException: Database lock acquisition failure: lockFile: org.hsqldb.persist.LockFile@76d682a[file =/data/explorecalifornia.lck, exists=false, locked=false, valid=false, ] method: openRAF reason: java.io.FileNotFoundException: /data/explorecalifornia.lck (No such file or directory)
    at org.hsqldb.error.Error.error(Unknown Source)
    at org.hsqldb.error.Error.error(Unknown Source)
    at org.hsqldb.persist.LockFile.newLockFileLock(Unknown Source)
    at org.hsqldb.persist.Logger.acquireLock(Unknown Source)
    at org.hsqldb.persist.Logger.openPersistence(Unknown Source)
    at org.hsqldb.Database.reopen(Unknown Source)
    at org.hsqldb.Database.open(Unknown Source)
    at org.hsqldb.DatabaseManager.getDatabase(Unknown Source)
    at org.hsqldb.DatabaseManager.newSession(Unknown Source)
    at org.hsqldb.jdbc.JDBCConnection.<init>(Unknown Source)
    at org.hsqldb.jdbc.JDBCDriver.getConnection(Unknown Source)
    at org.hsqldb.jdbc.JDBCDriver.connect(Unknown Source)
    at java.sql.DriverManager.getConnection(DriverManager.java:571)
    at java.sql.DriverManager.getConnection(DriverManager.java:215)
    at com.lynda.javatraining.db.Main.main(Main.java:24)

B2
java.sql.SQLException: Database lock acquisition failure: lockFile: org.hsqldb.persist.LockFile@76d682a[file =/data/explorecalifornia.lck, exists=false, locked=false, valid=false, ] method: openRAF reason: java.io.FileNotFoundException: /data/explorecalifornia.lck (No such file or directory)
B3
C

谁能告诉我我做错了什么？谢谢。

Answer 1

数据库有一个锁定文件 explorecalifornia.lck 阻止通信。您应该删除锁定文件并重新启动数据库。当您不小心关闭数据库或系统时，可能会不时发生这种情况。

查看从命令行调用 shutdown 的命令语法.还有一个选项 how to shutdown server in Java .