问题
First, I am studying Java, but I am still very new to it, so complicated code will go over my head.
When I download a .jar file to say install a mod to minecraft and double click it, it doesn't run. The loading wheel goes for like two seconds and then stops, and nothing else happens. The .jar I know is set up right because it runs through cmd with the command
cd "wherever the file is"
java -jar "file name".jar
So I've already tried to run it with the default program set as javaw.exe in the java\jdk1.7.0_25\jre\bin. Same where nothing happens. So the file association is set to the right place. I am at a loss here.
It isn't so bad since I can still run them through cmd, but when I get to the part in the book about jars, I want to be able to run it through the Windows Explorer GUI, which is like half the benefit of using .jar files that I can see.
Is it possibly a registry error? I have seen a lot of questions specifically about this problem, but most of them it seems were problems with setting up the .jar, which I didn't do, and I don't think that is the case here.
I have Windows Vista 64bit.
If I wasn't specific enough, feel free to ask.
回答1:
I had the same problem, and it turns out that the .jar file association in the registry was broken. The following steps fixed it:
Open the Registry Editor, and navigate to HKEY_CLASSES_ROOT\jarfile\shell\open\command. Modify the value of the Default key as follows:
"[Location of your JRE]\bin\javaw.exe" -jar "%1" %*
Replace [Location of your JRE] with the root directory of your JRE installation.
For example:
"C:\Program Files\Java\jre7\bin\javaw.exe" -jar "%1" %*
Repeat the above steps for HKEY_LOCAL_MACHINE\SOFTWARE\Classes\jarfile\shell\open\command.
I have a Windows 7 machine, but I assume this would work for 32-bit environments as well.
EDIT: Fixed the path in the example - it should use the "Program Files" directory and not "Program Files (x86)".
回答2:
If you don't care too much about understanding the underlying problem, this might help:
http://johann.loefflmann.net/en/software/jarfix/index.html
--and a double-clickable .jar needs to have Main-Class correctly set in MANIFEST.MF
回答3:
Just to reiterate - Meghan's answer fixed my problem of not being able to double-click to start a jar in Windows 7.
Open Registry editor
Navigate to HKEY_CLASSES_ROOT->jarfile->shell->open->command
Modify (Default) to
"[Path to working JRE]/bin/javaw.exe" -jar "%1" %*Make sure .jar files are opened by [Path to working JRE]/bin/javaw.exe by default
回答4:
You have to do RightClick on the jar file and select open with... then, Choose default program... (i think that's the correct translation for "Elegir programa predeterminado" in spanish). On the Open with dialog select Java(TM) Platform SE binary. If you don't see that option you should search for the javaw.exe in your java installation folder, and select it. Also you should check Use the selected program to open this kind of file
Best regards.
回答5:
Right click the jar and open with winzip or winrar
回答6:
According to Johann Loefflmann, the root cause for the problem above is, that a program has stolen the .jar association. And he is right! Just follow the link below and install a small file JARFIX and the association will be set back and you can double click any jar file and run it in windows. It works for me (I have the same problem and before these I tried all solutions mentioned in the forum and failed).
https://johann.loefflmann.net/en/software/jarfix/index.html
来源：https://stackoverflow.com/questions/18434292/i-can-run-jar-files-through-cmd-but-i-cannot-double-click-them