I wanted to create an executable of my java application in eclipse, but instead of having to hosting my database, I wanted to putting inside the application's folders when creating the executable, what do I need to do to accomplish this, and also, what would the path of the class with the code to connect to the database be like?
Thanks in advance.
You cannot do this with MySQL, since MySQL runs in "server mode" only.
To do what you want you would need to change the database to one of the following:
H2. See documentation. URL: jdbc:h2:file:<path>/<database>
HyperSQL. See documentation. URL: jdbc:hsqldb:file:<path>/<database>
Apache Derby. See documentation. URL: jdbc:derby:<path>/<database>
In all three databases the corresponding JDBC driver includes the WHOLE database engine itself. Therefore, just by connecting to the database, you'll get a fully running instance of it.
Now, these databases can work on several modes:
Embedded+File System: the JDBC URL will include a [relative or absolute] path to a directory where the database tables and data are persisted.
Embedded+Memory: the JDBC URL will specify all data will be stored in memory and will be lost once the connection is closed.
Server Mode: the JDBC URL will point to an [external/remote] host:port where the database engine is running. This is similar to MySQL.
According to your question, the first option seems to be the one you need. As a personal note, I find H2 and HyperSQL are easier to set up compared to Derby, since each one comes into a single JAR file.
A database is either located on a user's local machine (for development), or on a server on the internet (for real world use). You could create a Java class that imitates a database, but it's impossible to put a database inside an executable.
Related
I couldn't find an answer to this question. How can I export a Java project that makes use of a PostgreSQL database?
I want to use the same database on another computer. Do I need to export the database itself with the project? How can this be done?
What should the connection URL be, so that the database is accessible on another computer?
I'm using JDBC, and I'm on Windows.
Thanks in advance.
EDIT: Wouldn't I also need to dynamically retrieve the username and password on the other computer, instead of using the specific username and password I have on my computer in PostgreSQL?
It really depends on what you want to achieve.
Shared database between hosts
Do you want the application on both computers to use the same database, so that changes made by one are seen on the other? If so, you need to configure each copy of the application to connect to the same database instance on one of the machines. This is usually done by changing the JDBC URL. You'll need to configure PostgreSQL on the machine that'll be the database server so it allows connections from the other hosts, ensure they can talk to each other over TCP/IP, etc.
Fresh DB on each host
Do you want each install to have a separate instance of the database, so changes made on one have no effect on the other, and where each instance starts out with a blank, empty database (or one with only static contents like lookup tables)? If so, you should generally define the database using SQL scripts, then have the application run the SQL scripts when first installed on a machine. If you've defined the database by hand so far, you can use pg_dump to create a SQL script that you can use as the basis for this, but I really advise you to look into tools like Liquibase for schema management instead.
"Fork" current state
Do you want each instance of the application on a machine to have an independent database, so changes made on one have no effect on other instances on other machines, but where the starting state of an install is what was in the database on the other host? If so, you need to dump and reload the database alongside the application, using pg_dump -Fc and pg_restore. You can automate this within your application / build system using tools like ProcessBuilder, or do it manually.
There's no generic, canned way to do this. It'll require you to define an application deployment procedure, maybe produce an installer, etc.
I read a lot of posts like:
querying embedded database in netbeans using derby
But still I'm having trouble to understand embedded databases.
1) I create a Derby database on Netbeans and I can create tables, link the database to a form and submit the data and update the records with no problem.
2) The problem arises when I want to make the program portable. I apply Clean and Build, then copy the dist folder and also copy the libraries, database, etc ... but when running the program does not recognize the database
3) I read in several places that it is appropriate that the database is created by code using something like
String host = "jdbc: derby: // localhost: 1527 / EmployeesCreateTrue; create = true"
and not creating the database on Netbeans Service...
If I do this procedure with code the database is created but it does not appear or does not allow me to connect from NetBeans and I wish I could fix it to create tables from NetBeans and not from code.
4) I read manuals "how to import a database from Derby to NetBeans" and it doesn't work...
Question: What is the best way to create a database, tables and connect to NetBeans for the final application to be easily portable?
1) Create the database on Netbeans with the wizzard?
or
2) Just plain code on the application?
I don't understand precisely what you mean by "the database is created but it does not appear."
I think if you were to explain that precisely, the community could probably help you.
There are three common reasons for "table does not exist" when you think you've created the tables; I've explained those cases in this answer: Is it necessary to create tables each time you connect the derby database?
Please let us know more information about your situation so that we can help you better understand the behavior of your application.
I'm not 100% sure if this is your problem, but a lot of problems people seem to have with Netbeans and Derby seems to come from the fact that they don't set derby.system.home explicitly. When you don't, Derby stores databases in the current directory, and that is likely different when working in the IDE, either in the Services tab, or your own code, than when you execute your app's jar as a standalone program. So the advice (which you will also find in the manual) is: always set derby.system.home. An alternative would be to use full paths to the databases, but that rarely works well for a real application that is deployed on different machines.
I had the same problem --had the derby db in the services but the netbeans coded programs didn't access it. I solved it by adding the derby database (copy paste) to the package in the Files section. I use Windows 7. Once I did that, I was able use multiple tables (before netbeans just ignored secondary tables and only allowed me to use the primary table).
I have a website written in JSF backed by MySQL database running on Tomcat 7. Now there is only one missing part - project first setup/installation. I want my war when deployed for the first time to offer you installation/first time setup with following steps:
Setup database - enter mysql parameters needed to successfully connect to mySQL server.
Write those parameters into some external file for further use (of course encrypted).
Install database - take a file with SQL inside that creates all the tables in database.
Create first user etc.
Delete installation files.
Similar steps are used in PHP Content Management systems like Drupal. I know perfectly how to work with files in Java. I also know, that I can't change content inside a jar once it's deployed and running, so I have to put my files with SQL and database parameters somewhere else.
My questions are
Where can I put these configuration files to make them readable ? And how ?
Is there another way to achieve this goal ? What is commonly used by Java developers ?
Thank you for your answers.
You can use JPA(Java persistent API) and put all this configuration on persistance.xml and set the schema generation to create Table also the things related to role and user is dependent to application server.
JPA use ORM(object relational mapping) to map between you objects (entity) and database tables
i have a java project with mysql database
i am using advance installer to create a setup file...
i can embed jre to run the software(Without installing java in the system).
like wise,i want to embed the mysql database (system doesn't contains mysql )...
.There is any software to embed mysql database in my project setup...
MySQL is very difficult to embed correctly and there are a number of failure states that might occur if it is not shut down using the proper procedure. SQLite is a much better engine for this sort of thing and is used by a number of applications as a persistent backing store. While not as powerful as MySQL, it is much more resilient. It also has the advantage of not requiring a separate process.
SQLite's storage method is to persist things into a file that can be copied, moved, or backed-up without any issues. MySQL involves many such files, some of which are in an inconsistent state unless the correct FLUSH is called.
The best you can do with MySQL is bundle it, not embed it, but then you'll be responsible for setting it up on the host system, configuring it correctly, running the appropriate maintenance procedures, and providing some kind of back-up facility for the database itself.
My aim is to create a local database that can be read and written to with Java. I have some experience with manipulating a local sqlite database with Python, and with interacting with existing networked databases on Microsoft Azure via VB.Net, but the Java formulation for creating a database is escaping me.
Most sources (like the JDBC Docs) seem to assume that you are accessing a database through a network protocol, or a database hosted on localhost. My desired implementation is to create and store the database in a file (or collection of files), so that it can be stored and accessed locally, without network connectivity (presumable through the "file:" protocol).
The JDBC Tutorial looks like it will be very useful once I am up and running, but is currently beyond my scope, since I don't even have an existing database yet.
Many sources have suggested solutions like H2, MySQL, Derby, or Hypersonic DB. However, I'm loath to install extensions (if that's the right term) for a number of reasons:
This project is initially intended to help me learn my way around Java - widening the scope of the project will dilute my experience with the "base" language and, probably, increase the temptation to engage in "cargo cult programming"
If this project does ever get distributed to other users (admittedly unlikely, but still!), I don't want to force them into installing more than the core of Java.
I simply don't know how to install extensions (add-ons? modules?) in Java - one baby-step at a time!
For similar reasons, installing Microsoft SQL Server would not be productive.
This answer looks close to what I'm aiming for; however, it gives the error:
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/?user=root&password=rootpassword
and trying "jdbc:file://targetFile.sql" gives a similar error.
I've seen the term "embedded" database, which I think is a subset of "local database" (i.e. a local database is stored on the same system - an embedded database is a local database that is only used by a single application) - if I've got those definitions wrong, please feel free to correct me!
Most likely, the reason for which you are getting the error, is due to the fact that you are not registering the driver (using reflection...) before actually using it for establishing a connection and so on.
Presumably you will want to do something along the lines of Class.forName("driver")
and then cast that if necessary and then registering it in the DriverManager before calling the getConnection() method.
Here is a very useful link that might help you out in solving the issue:
http://www.kfu.com/~nsayer/Java/dyn-jdbc.html
However, if you really want to use a local database/file you might want to have a look at SQLite, that might be one way to go about it, although I recommend going for the MySQL approach, as it is a lot easier to configure and learn how stuff works with JDBC.
If you are still considering SQLite check this out:
Java and SQLite
I see you need some guidance in importing external .jar files into your code (i.e. 3rd party libraries like the ones you will be using for a JDBC driver). Are you using an IDE (e.g. Eclipse, Netbeans, etc.) or are you writing in a text editor and compiling manually?
A number of embedded pure Java databases appeared recently, which have a really simple interface, usually just java.util.Map, don't involve using JDBC or other SQL artifacts, and store their data in a single file or directory:
Chronicle Map
JetBrains Xodus
MapDB
The main downside is that most of such databases provide only the simples key-value model.
DBC can be used with any database that has a JDBC driver, which isn't necessarily a database in "network mode", it can be used with embedded databases as well.
Here are some Java and embeddable databases:
http://www.h2database.com/html/main.html
http://db.apache.org/derby/
http://hsqldb.org/
Java's JDK does not include any implementation of a database nor drivers to access it. It only provides JDBC as an abstraction to connect to a "database". Is up to you to include all the needed libraries in your code.
If you want to have a self contained code you can simply include the .jar file of a embeddable database in you classpath. That way you can create the instance of the database in your code and minimize the external dependencies.
You can find here a list of java embeddable databases
You can find here an example of how to embed HSQLDB in your code.