Java无法在我的电脑上运行

Question

I had installed Java in my PC and it was working perfectly. Suddenly something went wrong and now I m not able to open swing applications and its showing the error 'Java not found'. But I can run the Eclipse IDE which also needed Java to run. So I decide to reinstall the Java, but when I tried to uninstall the Java it shows the Error 1723 - There is a problem with this Windows Installer Package. So I have installed a new JDK in another location and set the PATH. Still I am not able to run the Swing application.

Can anybody help me on this?

Answer 1

How are you running your swing application? If it's from the command line like java mySwingApp and you're getting java not found then your PATH isn't set properly. Make sure that the java/bin directory is on your PATH not just the top level directory. You can test your PATH by just typing java in a console window - it should print the java help page.

If you're not running from a terminal like above, then you may need to set a JAVA_HOME environment variable which points to your java installation folder. Here's a tutorial on setting JAVA_HOME Setting JAVA_HOME

Hope this helps,

Will

Answer 2

This is close to jakob's answer, about trying to get your Java install setup correctly again, just with a little more detail.

I had a similar problem on my Windows 7 box where I was trying to uninstall Java and do a clean install of a newer version. Something got messed up and I would get the 1723 error message during the uninstall and attempted reinstall. Here's information about how I was able to fix the problem, and maybe this will help you:

Look at the log files for the uninstall/reinstall. On Windows 7 they can be found at c:\\users\\username\\AppData\\Local\\Temp\\

The java_install.log didn't show any extra information, but I had several MSI##### log files that contained error messages about the failed uninstall. The message was: Error 1723.There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action UninstallJRE, entry: MSIUninstallJRE, library: C:\\Program Files\\Java\\jre6\\bin\\regutils.dll Error 1723.There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action UninstallJRE, entry: MSIUninstallJRE, library: C:\\Program Files\\Java\\jre6\\bin\\regutils.dll

There was indeed no regutils.dll file, and not even the bin directory was there. So I copied over a regutils.dll file from another computer, ran the uninstaller, and it worked. Then the new clean install of Java also worked.

So take a look at your logfiles and hopefully that will give you more detailed information about the 1723 error.

Answer 3

This usally happens when you delete Java files manually. If you try to uninstall Java and it fails, it generates a log file. Should be in C:\\Users[Username]\\AppData\\Local\\Temp Almost at the end the missing file(s) can be found. Try to copy that file(s) from a working installation to your computer. Then you should be able to uninstall your Java and install a new version.