Java: how to create a working .exe from a native installer?

问题

I have a program I want to be able to be installed easily by any user, and I thought creating a native installer was the way to go. I used Netbeans 8.0's functionalities (Project properties > Enable native packaging, and Package as). I was able to create a working native installer. After installation, I have the following file tree:

+-- Project
    \+-- app
         \+--lib (containing all the jars used by the project)
         \---Project.jar
         \---package.cfg
    \+--runtime
        \+--jre (contains the current jre)
    \---Project.exe

Executing the program from Project.jar works. However, when I try to launch Project.exe, I get the following error message on a window pop-up with no details whatsoever:

Failed due to exception from main class

To identify the source of the problem, I have used basic standard outputs and redirected them into a file thanks to the Windows command prompt. I got outputs until the first call to an external library. So it seems the library linking is not done. However, here's the content of my package.cfg file:

app.mainjar=Project.jar
app.mainclass=project/Main
app.classpath=lib/firstlibrary.jar lib/secondlibrary.jar

The classpath is specified but does not seem to be recognized. I have tried inverting the slash (\) and changing whitespaces for , or ; to no avail.

There is an easy way to reproduce the bug (Netbeans 8.0 and JDK 1.8u11):

Create a new Java project in Netbeans
Link any external library (.jar): right click on Libraries > Add jar/folder
In the main method, instantiate an object referencing that library.
Right click on the project's name > Properties > Deployment > Enable Native Packaging actions in project menu
Right click on your project > Package as > EXE installer
After build, go to the directory where the installer has been created, and launch the installer.
At the end of the installation, go to the installation directory, and start the .exe. The error should occur.

Any idea how to fix this?

回答1:

I just had a similar issue with a native-packaged JavaFX application where I was getting the "Failed due to exception from main class" error. My package.cfg looked the same as yours.

What I did to diagnose it was just to manually run the jar file (e.g. Project.jar) from the command line and see what the stacktrace was, e.g. if your Main class was in org.project.Project

java -cp Project.jar org.project.Project

Turns out for me that the URLs I had been using to load various files (e.g. the FXML files for JavaFX) packaged in the jar were causing issues - I was using relative URLs (e.g. "./blah.ext" or "../foo.txt" etc), but once I had changed the URLs to be absolute based on how the files were laid out in the jar it worked fine (e.g. "/org/project/blah.ext" and "/org/foo.txt").

回答2:

Same problem here, using these:

Java SE Version 8 Update 31 (build 1.8.0_31-b13)
NetBeans 8.0.2 (Patch 1)
Windows 7 Enterprise SP1 on Intel Core i7 (64-bit)
Inno Setup Compiler 5.5.5 (u) - Unicode

I also traced output by redirecting printlns, and it blew up the first time it called for an external library. I thought maybe I had the same problem as matt1 so I fixed all the relative paths, but no joy. I finally figured out that the installer was not creating the /app/lib folder with the external jar files. After manually copying the lib folder to the target installation folder it worked fine, even on a machine with no JRE installed (I'm working on a self-contained app).

The fix was to add a line to the build.xml:

   <target name="-post-jfx-deploy">
   <fx:deploy width="${javafx.run.width}" height="${javafx.run.height}" 
             nativeBundles="all"
             outdir="${basedir}/${dist.dir}" outfile="${application.title}">
      <fx:application name="${application.title}" mainClass="${javafx.main.class}"/>
      <fx:resources>
          <fx:fileset dir="${basedir}/${dist.dir}" includes="*.jar"/>
          <!--below is the magic bit that copies all the dependency jar files to the native package output-->
          <fx:fileset dir="${basedir}/${dist.dir}" includes="lib/*.jar"/>
      </fx:resources>
      <fx:info title="MyApp" vendor="MyVendor"/>
  </fx:deploy>          
</target>

The second fileset directive forces a copy of the jar dependencies from the lib folder, which fixed everything when deploying either as an EXE or an MSI.

回答3:

I thinks your main class is not correctly set to package. Instead of using Netbeans you can make exe from your jar file using exe4J.(please make sure main class is set from project > properties > run > main class

download exe4J from here

来源：https://stackoverflow.com/questions/25311598/java-how-to-create-a-working-exe-from-a-native-installer

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java

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