Store Zip File In Database Using Java
LINK - https://urluss.com/2t7h4Z
To save an image into database, you need to define a table column as blob data type in MySQL, or equivalent binary type in others database. In Hibernate side, you can declare a byte array variable to store the image data.
Hi mkyong,Similarly I want to store my .zip file in mysql database using hibernate framework in java.I tried the same thing that using byte array, I stored my .zip file .Here I faced a problem that ,I got the database session and able to save my class unfortunately it stops at transaction&commit. can you please help me how to overcome this issue!Thanks in advance!
thank you for this nice tutorial !but i see that the part //Get image from database, generate the images stored in DB on a disk directory ,which is redundant ,we have two images .is there a better solution to open the image in a jsf page without creating the image on the disk.
In embedded mode, an application opens a database from within the same JVM using JDBC.This is the fastest and easiest connection mode.The disadvantage is that a database may only be open in one virtual machine (and class loader) at any time.As in all modes, both persistent and in-memory databases are supported.There is no limit on the number of database open concurrently,or on the number of open connections.
In embedded mode I/O operations can be performed by application's threads that execute a SQL command.The application may not interrupt these threads, it can lead to database corruption,because JVM closes I/O handle during thread interruption.Consider other ways to control execution of your application.When interrupts are possible the async:file system can be used as a workaround, but full safety is not guaranteed.It's recommended to use the client-server model instead, the client side may interrupt own threads.
When using the server mode (sometimes called remote mode or client/server mode),an application opens a database remotely using the JDBC or ODBC API.A server needs to be started within the same or another virtual machine, or on another computer.Many applications can connect to the same database at the same time, by connecting to this server.Internally, the server process opens the database(s) in embedded mode.
The server can be started and stopped from within the application (using the server API),or automatically (automatic mixed mode). When using the automatic mixed mode,all clients that want to connect to the database (no matter ifit's an local or remote connection) can do so using the exact same database URL.
The database URL for connecting to a local database isjdbc:h2:[file:].The prefix file: is optional. If no or only a relative path is used, then the current workingdirectory is used as a starting point. The case sensitivity of the path and database name depend on theoperating system, however it is recommended to use lowercase letters only.The database name must be at least three characters long(a limitation of File.createTempFile).The database name must not contain a semicolon.To point to the user home directory, use ~/, as in: jdbc:h2:~/test.
Sometimes multiple connections to the same in-memory database are required.In this case, the database URL must include a name. Example: jdbc:h2:mem:db1.Accessing the same database using this URL only works within the same virtual machine andclass loader environment.
To access an in-memory database from another process or from another computer,you need to start a TCP server in the same process as the in-memory database was created.The other processes then need to access the database over TCP/IP or TLS,using a database URL such as: jdbc:h2:tcp://localhost/mem:db1.
By default, a new database is automatically created if it does not exist yetwhen the embedded url is used.To create an encrypted database, connect to it as it would already exist locally using the embedded URL.
The encryption algorithm is set in the database URL, and the file password is specified in the password field,before the user password. A single space separates the file passwordand the user password; the file password itself may not contain spaces. File passwordsand user passwords are case sensitive. Here is an example to connect to apassword-encrypted database:
To encrypt an existing database, use the ChangeFileEncryption tool.This tool can also decrypt an encrypted database, or change the file encryption key.The tool is available from within the H2 Console in the tools section, or you can run it from the command line.The following command line will encrypt the database test in the user home directorywith the file password filepwd and the encryption algorithm AES:
Whenever a database is opened, a lock file is created to signal other processesthat the database is in use. If database is closed, or if the process that openedthe database terminates, this lock file is deleted.
By default, a database is closed when the last connection is closed. However, if it is never closed,the database is closed when the virtual machine exits normally, using a shutdown hook.In some situations, the database should not be closed in this case, for example because thedatabase is still used at virtual machine shutdown (to store the shutdown process in the database for example).For those cases, the automatic closing of the database can be disabled in the database URL.The first connection (the one that is opening the database) needs toset the option in the database URL (it is not possible to change the setting afterwards).The database URL to disable database closing on exit is:
In addition to the settings already described,other database settings can be passed in the database URL.Adding ;setting=value at the end of a database URL is thesame as executing the statement SET setting value just afterconnecting. For a list of supported settings, see SQL Grammaror the DbSettings javadoc.
Usually, the database opens the database file with the access moderw, meaning read-write (except for read only databases,where the mode r is used).To open a database in read-only mode if the database file is not read-only, useACCESS_MODE_DATA=r.Also supported are rws and rwd.This setting must be specified in the database URL:
While a database is closed, the files can be moved to another directory, and they canbe renamed as well (as long as all files of the same database start with the samename and the respective extensions are unchanged).
Text comparison in MariaDB is case insensitive by default, while in H2 it is case sensitive (as in most other databases).H2 does support case insensitive text comparison, but it needs to be set separately,using SET IGNORECASE TRUE.This affects comparison using =, LIKE, REGEXP.
Text comparison in MySQL is case insensitive by default, while in H2 it is case sensitive (as in most other databases).H2 does support case insensitive text comparison, but it needs to be set separately,using SET IGNORECASE TRUE.This affects comparison using =, LIKE, REGEXP.
Use the same URL for all connections to this database. Internally, when using this mode,the first connection to the database is made in embedded mode, and additionally a serveris started internally (as a daemon thread). If the database is already open in another process,the server mode is used automatically. The IP address and port of the server are stored in the file.lock.db, that's why in-memory databases can't be supported.
The application that opens the first connection to the database uses the embedded mode,which is faster than the server mode. Therefore the main application should openthe database first if possible. The first connection automatically starts a server on a random port.This server allows remote connections, however only to this database (to ensure that,the client reads .lock.db file and sends the random key that is stored there to the server).When the first connection is closed, the server stops. If other (remote) connections are stillopen, one of them will then start a server (auto-reconnect is enabled automatically).
All processes need to have access to the database files.If the first connection is closed (the connection that started the server), open transactions of other connections will be rolled back(this may not be a problem if you don't disable autocommit).Explicit client/server connections (using jdbc:h2:tcp:// or ssl://) are not supported.This mode is not supported for in-memory databases.
Here is an example how to use this mode. Application 1 and 2 are not necessarily startedon the same computer, but they need to have access to the database files. Application 1and 2 are typically two different processes (however they could run within the same process).
The simplest way to enable the trace option is setting it in the database URL.There are two settings, one for System.out(TRACE_LEVEL_SYSTEM_OUT) tracing,and one for file tracing (TRACE_LEVEL_FILE).The trace levels are0 for OFF,1 for ERROR (the default),2 for INFO, and3 for DEBUG.A database URL with both levels set to DEBUG is:
When using a high trace level, the trace file can get very big quickly.The default size limit is 16 MB, if the trace file exceeds this limit, it is renamed to.old and a new file is created.If another such file exists, it is deleted.To limit the size to a certain number of megabytes, useSET TRACE_MAX_FILE_SIZE mb.Example:
The generated file Test.java will contain the Java source code.The generated source code may be too large to compile (the size of a Java method is limited).If this is the case, the source code needs to be split in multiple methods.The password is not listed in the trace file and therefore not included in the source code.
By default, this database uses its own native 'trace' facility. This facility is called 'trace' and not'log' within this database to avoid confusion with the transaction log. Trace messages can bewritten to both file and System.out.In most cases, this is sufficient, however sometimes it is better to use the samefacility as the application, for example Log4j. To do that, this database support SLF4J. 2b1af7f3a8