每个人都在谈论Backup Hsqldb，但我需要的是备份嵌入文件...
我使用的是Spring JPA，应用程序一直在运行，因此文件正在使用中，因为没有DBMS，我想知道是否有备份和恢复的方法？ 如果有，请指导我......
否则，我虽然复制了数据库文件，但是以某种方式（不知道如何）将spring JPA置于离线模式，然后将那些我在java中不知道的文件压缩，然后让它们用户下载它，如果弹簧允许它......某种程度上（因为我使用独立的弹簧启动，这是一个单独的文件，它并没有提供很多那些花哨的文件夹，我们可以指出他们作为网站网址...）
最后，在任何情况下，我都想将文件发送给客户。
很抱歉，如果我不知道这一点，我来自C＃，5年后，这是我第二次使用Java，我从来没有在其中使用过它。
虽然我不确定我是否可以从运行数据库制作一个zip文件，并将其存储在那个地方......我通过搜索编写了这个代码，我找到了几个返回当前目录的方法，但是没有他们指向我想要的目录...其中一个，在调试它指向非常内部的位置，像targer / class / x / y / z，在我将它打包到jar文件后，它可能是不同的，另一个指向C /.... / temp，...我需要写入我的DB文件所在的位置，然后传递这些文件来制作zip文件功能，并告诉用户下载文件
@RestController
@RequestMapping(value = "/rest/database-manager")
public class DatabaseManager {
private ServletContext servletContext;
private final Environment env;
@Autowired
public DatabaseManager(Environment env, ServletContext servletContext) {
this.env = env;
this.servletContext = servletContext;
}
@RequestMapping(value = "/get-backup", method=RequestMethod.GET)
private FileSystemResource getBackup() throws IOException {
//String directory = DemoApplication.class.getResource("").getPath();
String outputLocation = servletContext.getRealPath("./");
String dataBaseFilePath = servletContext.getRealPath(env.getProperty("application.database-file-location"));
Calendar cal = new GregorianCalendar();
String zipFile = outputLocation + "/backup-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.YEAR)), 4, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MONTH)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.DAY_OF_MONTH)), 2, "0")
+ "-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.HOUR)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MINUTE)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.SECOND)), 2, "0")
+ ".zip";
ZipUtil.ToZip(new String[]{""}, zipFile);
return new FileSystemResource(zipFile);
}
}
zip功能：
public class ZipUtil {
public static void ToZip(String inputFiles[], String outputFile) throws IOException {
//create byte buffer
byte[] buffer = new byte[1024];
/*
* To create a zip file, use
*
* ZipOutputStream(OutputStream out)
* constructor of ZipOutputStream class.
*/
//create object of FileOutputStream
FileOutputStream fout = new FileOutputStream(outputFile);
//create object of ZipOutputStream from FileOutputStream
ZipOutputStream zout = new ZipOutputStream(fout);
for (int i = 0; i < inputFiles.length; i++) {
//create object of FileInputStream for source file
FileInputStream fin = new FileInputStream(inputFiles[i]);
/*
* To begin writing ZipEntry in the zip file, use
*
* void putNextEntry(ZipEntry entry)
* method of ZipOutputStream class.
*
* This method begins writing a new Zip entry to
* the zip file and positions the stream to the start
* of the entry data.
*/
zout.putNextEntry(new ZipEntry(inputFiles[i]));
/*
* After creating entry in the zip file, actually
* write the file.
*/
int length;
while ((length = fin.read(buffer)) > 0) {
zout.write(buffer, 0, length);
}
/*
* After writing the file to ZipOutputStream, use
*
* void closeEntry() method of ZipOutputStream class to
* close the current entry and position the stream to
* write the next entry.
*/
zout.closeEntry();
//close the InputStream
fin.close();
}
//close the ZipOutputStream
zout.close();
}
}
我不确定Produ是否会做任何事情，因为我直接写入内部的回复，然后返回void。
我的回应方法：
@RequestMapping(value = "/get-backup", method = RequestMethod.GET)
private void getBackup(HttpServletResponse response) throws IOException {
/*//String directory = DemoApplication.class.getResource("").getPath();
String outputLocation = servletContext.getRealPath("./");
String dataBaseFilePath = servletContext.getRealPath(env.getProperty("application.database-file-location"));
Calendar cal = new GregorianCalendar();
String zipFile = outputLocation + "/backup-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.YEAR)), 4, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MONTH)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.DAY_OF_MONTH)), 2, "0")
+ "-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.HOUR)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MINUTE)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.SECOND)), 2, "0")
+ ".zip";
SQLQuery query = session.createSQLQuery("BACKUP DATABASE TO '/tmp/backup.tar.gz' BLOCKING");
query.executeUpdate();*/
File zipFile = null;
Calendar cal = new GregorianCalendar();
String prefix = "DBK-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.YEAR)), 4, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MONTH)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.DAY_OF_MONTH)), 2, "0")
+ "-"
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.HOUR)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.MINUTE)), 2, "0")
+ StrMgr.leftPad(String.valueOf(cal.get(Calendar.SECOND)), 2, "0");
String suffix = ".tar.gz";
zipFile = File.createTempFile(prefix, suffix);
zipFile.delete();
databaseManagerRepository.Backup(zipFile.getAbsolutePath());
response.setContentType("application/gzip");
response.setHeader("Content-disposition", "attachment; filename=" + zipFile.getName());
// OutputStream out = response.getOutputStream();
// FileInputStream in = new FileInputStream(zipFile);
/*
* copy from in to out
*/
OutputStream out = null;
FileInputStream in = null;
try {
out = response.getOutputStream();
in = new FileInputStream(zipFile);
byte[] buffer = new byte[4096]; // To hold file contents
int bytes_read; // How many bytes in buffer
// Read a chunk of bytes into the buffer, then write them out,
// looping until we reach the end of the file (when read() returns
// -1). Note the combination of assignment and comparison in this
// while loop. This is a common I/O programming idiom.
while ((bytes_read = in.read(buffer)) != -1)
// Read until EOF
out.write(buffer, 0, bytes_read); // write
}
catch (Exception ex){
System.out.print(ex.getMessage());
}
// Always close the streams, even if exceptions were thrown
finally {
if (in != null)
try {
in.close();
} catch (IOException e) {
;
}
if (out != null)
try {
out.close();
} catch (IOException e) {
;
}
}
zipFile.delete();
}
我的备份本机SQL操作执行程序
@Repository
public class DatabaseManagerRepository {
@PersistenceContext
private EntityManager entityManager;
/*The query force us to use transaction, and since the DB is online and we use spring, it also force us to use spring transaction*/
@Transactional(rollbackFor = {Exception.class})
public void Backup(String outputDir) {
//NOT BLOCKING -> For large database, backup is performed while the database perform other operations
//AS FILES -> We only define directory not the file itself
Query q = entityManager.createNativeQuery("BACKUP DATABASE TO '" + outputDir + "' BLOCKING"/*" AS FILES"*/);
q.executeUpdate();
}
}
答案 0 :(得分：1)
备份与HSQLDB服务器或嵌入式数据库相同。您执行SQL语句：
BACKUP DATABASE TO <directory name> BLOCKING AS FILES
目录名是存储备份文件的目标目录的路径。例如BACKUP DATABASE TO 'C://db_backups/' BLOCKING AS FILES
http://hsqldb.org/doc/2.0/guide/management-chapt.html#mtc_online_backup
AS FILES备份数据库会创建一组您可以压缩的文件。