本文主要介绍 HSQLDB 的基本使用，文中所使用到的软件版本：Java 11.0.22、HSQLDB 2.7.2。
1、进程内模式
直接使用 JDBC 连接数据库即可，如果数据库不存在会自动创建。
1.1、file 数据库
@Test public void inProcessFile() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:file:d:/temp/" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close(); }private void business(Connection con) throws SQLException {String tableName = "a_student";Statement st = con.createStatement();String sql = "select 1 from INFORMATION_SCHEMA.TABLES where upper(table_schema)=? and upper(table_name)=?";PreparedStatement pst = con.prepareStatement(sql);pst.setString(1, "PUBLIC");pst.setString(2, tableName.toUpperCase());ResultSet rs = pst.executeQuery();if (!rs.next()) {//表不存在则创建并初始化数据，这里根据业务需要进行操作st.executeUpdate("create table " + tableName + "(id int, name varchar(32))");st.executeUpdate("insert into " + tableName + "(id,name) values (1,'李白')");st.executeUpdate("insert into " + tableName + "(id,name) values (2,'杜甫')");}rs = st.executeQuery("select * from " + tableName);while (rs.next()) {log.info("id={},name={}", rs.getInt("id"), rs.getString("name"));} }
1.2、mem 数据库
@Test public void inProcessMem() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:mem:" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close(); }
1.3、res 数据库
@Test public void inProcessRes() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码,数据库文件位于某个依赖 jar 文件的 db 目录中Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:res:db/" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close(); }
2、服务器模式
2.1、HyperSQL HSQL Server
可以通过如下命令启动 HyperSQL HSQL Server，假设当前位于 HSQLDB 安装包的 data 目录中：
java -cp ../lib/hsqldb.jar org.hsqldb.server.Server --database.0 file:d:/temp/mydb --dbname.0 test #启动file数据库，数据库文件保存在d:/temp目录下，数据名称为 test java -cp ../lib/hsqldb.jar org.hsqldb.server.Server --database.0 mem:mydb --dbname.0 test #启动mem数据库，数据名称为 test
可以添加其他参数来调整数据库的默认行为，查看所有参数：
java -cp ../lib/hsqldb.jar org.hsqldb.server.Server --help
相关参数如下：
Usage: java org.hsqldb.server.WebServer [options]+-----------------+------------ +------------+------------------------------+ | OPTION | TYPE | DEFAULT | DESCRIPTION | +-----------------+-------------+------------+------------------------------| | --help | - | - | displays this message | | --address | name|number | any | server inet address | | --port | number | 80/443 | port at which server listens | | --database.i | [type]spec | 0=test | name of database i | | --dbname.i | alias | - | url alias for database i | | --root | path | ./ | path to web root | | --default_page | file | index.html | default web page | | --silent | true|false | true | false => display all queries | | --trace | true|false | false | display JDBC trace messages | | --tls | true|false | | HTTPS (secure) sockets | | --no_system_exit| true|false | false | do not issue System.exit() | | --remote_open | true|false | false | can open databases remotely | | --props | filepath | | file path of properties file | +-----------------+-------------+------------+------------------------------+The web server looks for a 'webserver.properties' file in the current directory and loads properties from it if it exists. Command line options override those loaded from the 'webserver.properties' file.
启动后使用 JDBC 访问数据库：
@Test public void hsqlServer() throws SQLException {String dbName = "test";Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:hsql://localhost:9001/" + dbName, "SA", "");log.info("con={}", con);business(con);con.close(); }
2.2、HyperSQL HTTP Server
可以通过如下命令启动 HyperSQL HTTP Server，假设当前位于 HSQLDB 安装包的 data 目录中：
java -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --database.0 file:d:/temp/mydb --dbname.0 test #启动file数据库，数据库文件保存在d:/temp目录下，数据名称为 test java -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --database.0 mem:mydb --dbname.0 test #启动mem数据库，数据名称为 test
可以添加其他参数来调整数据库的默认行为，查看所有参数：
java -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --help
相关参数如下：
Usage: java org.hsqldb.server.WebServer [options]+-----------------+------------ +------------+------------------------------+ | OPTION | TYPE | DEFAULT | DESCRIPTION | +-----------------+-------------+------------+------------------------------| | --help | - | - | displays this message | | --address | name|number | any | server inet address | | --port | number | 80/443 | port at which server listens | | --database.i | [type]spec | 0=test | name of database i | | --dbname.i | alias | - | url alias for database i | | --root | path | ./ | path to web root | | --default_page | file | index.html | default web page | | --silent | true|false | true | false => display all queries | | --trace | true|false | false | display JDBC trace messages | | --tls | true|false | | HTTPS (secure) sockets | | --no_system_exit| true|false | false | do not issue System.exit() | | --remote_open | true|false | false | can open databases remotely | | --props | filepath | | file path of properties file | +-----------------+-------------+------------+------------------------------+The web server looks for a 'webserver.properties' file in the current directory and loads properties from it if it exists. Command line options override those loaded from the 'webserver.properties' file.
启动后使用 JDBC 访问数据库：
@Test public void httpServer() throws SQLException {String dbName = "test";Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:http://localhost:80/" + dbName, "SA", "");log.info("con={}", con);business(con);con.close(); }
2.3、HyperSQL HTTP Servlet
这种方式使用较少，这里就不详细介绍，可参考源文件 src/org/hsqldb/server/Servlet.java 查看详细信息。
3、混合模式
应用通过代码的方式启动数据库服务，应用内访问数据库可以使用进程模式，其他应用通过服务器模式访问。下面衍生通过代码分别启动 HyperSQL HSQL Server 和 HyperSQL HTTP Server，然后模拟其他应用访问数据库。
3.1、HyperSQL HSQL Server
@Test public void hsqlServer2() throws Exception {HsqlProperties p = new HsqlProperties();//三种数据库类型，根据需要选择合适的一个p.setProperty("server.database.0","file:d:/temp/mydb");//p.setProperty("server.database.0","mem:mydb");//p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中p.setProperty("server.dbname.0","test");Server server = new Server();server.setProperties(p);server.start();CountDownLatch countDownLatch = new CountDownLatch(1);new Thread(() -> {try {//模拟其他应用访问 hsqlServer();} catch (Exception e) {e.printStackTrace();}countDownLatch.countDown();}).start();countDownLatch.await();server.shutdownCatalogs(1);server.stop(); }
Server 的属性配置参数可参考 2.1 中启动数据库时的命令行参数。
3.2、HyperSQL HTTP Server
@Test public void httpServer2() throws Exception {HsqlProperties p = new HsqlProperties();//三种数据库类型，根据需要选择合适的一个//p.setProperty("server.database.0","file:d:/temp/mydb");//p.setProperty("server.database.0","mem:mydb");p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中p.setProperty("server.dbname.0","test");WebServer webServer = new WebServer();webServer.setProperties(p);webServer.start();CountDownLatch countDownLatch = new CountDownLatch(1);new Thread(() -> {try {//模拟其他应用访问 httpServer();} catch (Exception e) {e.printStackTrace();}countDownLatch.countDown();}).start();countDownLatch.await();webServer.stop(); }
WebServer 的属性配置参数可参考 2.2 中启动数据库时的命令行参数。
完整代码：
package com.abc.demo.db;import lombok.extern.slf4j.Slf4j; import org.hsqldb.Server; import org.hsqldb.persist.HsqlProperties; import org.hsqldb.server.WebServer; import org.junit.Test;import java.sql.*; import java.util.concurrent.CountDownLatch;@Slf4j public class HSQLCase {@Testpublic void inProcessFile() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:file:d:/temp/" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close();}@Testpublic void inProcessMem() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:mem:" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close();}@Testpublic void inProcessRes() throws SQLException {String dbName = "test";//用户名密码为第一次连接设置的密码,数据库文件位于某个依赖 jar 文件的 db 目录中Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:res:db/" + dbName, "admin", "123456");log.info("con={}", con);business(con);con.close();}@Testpublic void hsqlServer() throws SQLException {String dbName = "test";Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:hsql://localhost:9001/" + dbName, "SA", "");log.info("con={}", con);business(con);con.close();}@Testpublic void httpServer() throws SQLException {String dbName = "test";Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:http://localhost:80/" + dbName, "SA", "");log.info("con={}", con);business(con);con.close();}@Testpublic void hsqlServer2() throws Exception {HsqlProperties p = new HsqlProperties();//三种数据库类型，根据需要选择合适的一个p.setProperty("server.database.0","file:d:/temp/mydb");//p.setProperty("server.database.0","mem:mydb");//p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中p.setProperty("server.dbname.0","test");Server server = new Server();server.setProperties(p);server.start();CountDownLatch countDownLatch = new CountDownLatch(1);new Thread(() -> {try {//模拟其他应用访问 hsqlServer();} catch (Exception e) {e.printStackTrace();}countDownLatch.countDown();}).start();countDownLatch.await();server.shutdownCatalogs(1);server.stop();}@Testpublic void httpServer2() throws Exception {HsqlProperties p = new HsqlProperties();//三种数据库类型，根据需要选择合适的一个//p.setProperty("server.database.0","file:d:/temp/mydb");//p.setProperty("server.database.0","mem:mydb");p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中p.setProperty("server.dbname.0","test");WebServer webServer = new WebServer();webServer.setProperties(p);webServer.start();CountDownLatch countDownLatch = new CountDownLatch(1);new Thread(() -> {try {//模拟其他应用访问 httpServer();} catch (Exception e) {e.printStackTrace();}countDownLatch.countDown();}).start();countDownLatch.await();webServer.stop();}private void business(Connection con) throws SQLException {String tableName = "a_student";Statement st = con.createStatement();String sql = "select 1 from INFORMATION_SCHEMA.TABLES where upper(table_schema)=? and upper(table_name)=?";PreparedStatement pst = con.prepareStatement(sql);pst.setString(1, "PUBLIC");pst.setString(2, tableName.toUpperCase());ResultSet rs = pst.executeQuery();if (!rs.next()) {//表不存在则创建并初始化数据，这里根据业务需要进行操作st.executeUpdate("create table " + tableName + "(id int, name varchar(32))");st.executeUpdate("insert into " + tableName + "(id,name) values (1,'李白')");st.executeUpdate("insert into " + tableName + "(id,name) values (2,'杜甫')");}rs = st.executeQuery("select * from " + tableName);while (rs.next()) {log.info("id={},name={}", rs.getInt("id"), rs.getString("name"));}} }
package com.abc.demo.db;import lombok.extern.slf4j.Slf4j;import java.sql.*;@Slf4j public class JdbcUtil {private JdbcUtil() {}public static Connection getConnection(String driver, String url, String username, String password) {Connection con = null;try {Class.forName(driver);con = DriverManager.getConnection(url, username, password);} catch (ClassNotFoundException | SQLException e) {log.warn("url={},username={},password={}", url, username, password);e.printStackTrace();}return con;} }
