问题
I am really new to database and this is my first program in database using java Netbeans 7.1 --- It is summer on our country now and I am a student with the course I.T. Our next subject on programming is about database and since there's no class I spend my time learning database for preparation for the next school semester and I refer to this site as my guide for the first database program I currently making now.
http://www.homeandlearn.co.uk/java/databases_and_java_forms.html
I did everything in the tutorial and I actually done doing the program.
The final thing I did is I clean and build the program since I want the program to run with out opening the netbeans again I downloaded the JRE and make my database_form.jar as a jar executable. "database_form" the name of my Netbeans Project. I do that by making javaw in JRE.7 as my dafault when opening any jar files.
Anyway, this is how i run the program.
- Running Program in Netbeans IDE
Using Netbeans, before my program works I first need to "Start Server" on JavaDB. because if I didn't do that an Exception occurred "Err. connecting to server localhost 1527 and so on"
- Running Program using jar executable alone.
The Problem is there's an Exception and Err in connecting still occurred.
What I want to achieve?
I want the program to run without opening the Netbeans IDE and going to Java DB to click the "Start Server", I dont want to do that anymore. Or my second option is to start the server using command prompt so that I just have to make a bat file so that whenever I open my program database_form.jar I just place the bat file on my desktop and run it.
Second Problem! Actually, I already try my second option by using command prompt to start the server but I forgot how I did it, I just found it on some website the only thing I remember is the Exception says "Failed to lunch the server because the database Employees is missing. Employees is the name of my created database.
The O.S. I am using is Windows 7.
Thank you for all the reply and sorry for the long text I just want to be specific, :D
回答1:
Right, from your description there seems to be a couple of things you are confusing.
First, databases are typically run as servers with multiple clients connecting to them thus allowing they contain to be shared. When you start Java DB you are starting the Java DB database server.
That said, lightweight databases, such as Java DB can be run in an embedded mode as explained here. Remember that the directory you point to with the derby.system.home property will need to contain the database files, if not you'll need to create that programatically too.
Second, there's various ways to run a Java application outside of an IDE, but jars themselves are not executable in the same way an exe file is in Windows.
The simplest way is to call the java executable passing the necessary classpath and the name of the class containing the main method. For example if I had a class called com.example.Application that had been compiled to a directory C:\dev\example\classes the following command line would run the application:
java -cp C:\dev\example\classes com.example.Application
If there were dependencies on external libraries, as there will be in your case on the Derby JDBC driver, then those would also need including in the classpath resulting in something like:
java -cp C:\dev\example\classes;C:\dev\lib\derby.jar com.example.Application
There's a full set of document on the Java launcher here.
Now, back to the jar. Like I said, jars are not executable but there is something that's know as an 'executable jar'. This is the same as any jar except there are some special additions to the manifest to specify the application entry point or main-class and the class-path as described here.
Once the main-class and class-path are specified in the jar's manifest, the following command line would run the application:
java -jar C:\dev\example.jar
You can even associate the jar extension with the java exe and double clicking the jar will cause the application to launch (though on a dev machine it's probably more useful that the jar extension be associated with WinZip or simlar in order to open that jar).
回答2:
The default database in Netbeans is Derby/JavaDB. So you need to:
- add the jar of javadb/derby in our classpath (it maybe already present, as it is bundled with java when you install it in Ubuntu)
- setup a path with the jdbc URI to save the database data
I personally recommend the usage of hsqldb or H2 for this: they support in-memory database, very useful for stand alone project with no persistence data or for tests.
回答3:
If you use window, add ODBC Data Sources from Administrative Tools to your Java Derby driver and run jar.
来源：https://stackoverflow.com/questions/10085778/how-to-run-database-program-outside-the-netbeans-ide