CODEWITHSUNDEEP
javajar
Omar Elio Torres Castillo
Omar Elio Torres Castillo

Reputation: 371

I get an error: An unexpected error occurred while trying to open file hola.jar

i am using Linux ubuntu and i have created a java program named hola.java which is the following program code, this program works perfectly

import javax.swing.*;
import java.awt.*;

public class hola extends JFrame {

JButton b1 = new JButton("presionar");

 hola(){

  super("Botones");
  setSize(250,250);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  FlowLayout flo=new FlowLayout();
  setLayout(flo);
  add(b1);
  setVisible(true);

  }

  public static void main(String[] args)
 {


    hola bt = new hola();
   }

}

This java program works perfectly when it runs Now I created a jar file of this program using in command line:

jar cf hola.jar hola.class

This creates a Jar file named hola.jar

I even wrote Main-Class: hola in the manifest.mf file.

When I try to run this by:

java -jar hola.jar

I get an error: An unexpected error occurred while trying to open file hola.jar

Please tell me how to run jar file so that I get an output :'( , what could be the possible reason that i can not run this program as a jar file, even the program works perfectly using "java hola.java"

Upvotes: 7

Views: 9760

Answers (5)

Andrej
Andrej

Reputation: 226

Downgrade JDK version.

I am using docker to run my java app and got this problem.

At first, for debugging, use -Xdiag

It will tell you whether it is permission, file size or other problem.

java -Xdiag -jar hola.jar

I also attempted to increase the maximum file size that Java allows for jar signatures by setting the system property jdk.jar.maxSignatureFileSize:

-Djdk.jar.maxSignatureFileSize=800000000

However, this did not resolve my issue.

The solution was to downgrade my JDK to version 17.0.7., based on a discussions

https://github.com/whitesource/unified-agent-distribution/issues/48#issuecomment-1647660586

https://github.com/SAP/SapMachine/issues/1450

After downgrading, the application started working as expected in Docker.

Upvotes: 0

JPBlanc
JPBlanc

Reputation: 72680

Just to help people that meet the error nowdays (03/2024):

Error: An unexpected error occurred while trying to open file ...

This issue occurs while trying to launch a jar with Java version 1.8.0_375 and later versions. Due to a new property (jdk.jar.maxSignatureFileSize) introduced in this version.The default this is set as 8MB(8000000 bytes), however, my signed jar is be around 150MB+ in size.

So add :

-Djdk.jar.maxSignatureFileSize=800000000

Upvotes: 0

Taylor Brockman
Taylor Brockman

Reputation: 319

Error can also happen with > 65535 files in the .jar on some OS

I experienced same error message attempting to launch via -jar:

$ java -jar app.jar
Error: An unexpected error occurred while trying to open file: app.jar

Root cause is that my sbt-assembly output .jar file contains more than 65535 entries.

$ zipinfo app.jar |wc -l
65543

Solution: Short term solution was removal of older dependencies to lower the number of assembled .class files below the 16 bit file count limit.

Long term solution will involve testing Zip64 jvm support on the target OS. Unsure of why the zip64 auto negotiation isn't occurring automatically.

This issue is reproducible using sbt-assembly 15.0, openjdk version "11.0.8" on MacOSX 10.15.7.

Start of the code review:

package java.util.zip;
...
public
class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {

    /**
     * Whether to use ZIP64 for zip files with more than 64k entries.
     * Until ZIP64 support in zip implementations is ubiquitous, this
     * system property allows the creation of zip files which can be
     * read by legacy zip implementations which tolerate "incorrect"
     * total entry count fields, such as the ones in jdk6, and even
     * some in jdk7.
     */
    private static final boolean inhibitZip64 =
        Boolean.parseBoolean(
            GetPropertyAction.privilegedGetProperty("jdk.util.zip.inhibitZip64"));

Upvotes: 3

virgo47
virgo47

Reputation: 2333

This error mostly indicates invalid MANIFEST.MF file. Perhaps long line, missing final line terminator, accidental empty line in the middle, ... many things can go wrong. Using -cp just goes around the problem, but does not fix the root cause.

Upvotes: 3

Balwinder Singh
Balwinder Singh

Reputation: 2282

To run a java file within a jar file, you don't need to open it. You simply need to ensure your classpath is having the given jar file

If the class is within a package then you can run using

java -cp hola.jar package.hola

If the class is not in a package then simply use

java -cp hola.jar hola

If you are not within the directory where hola.jar is located, then you can try following:

  • In case of within package

    java -cp /locationOfJar/hola.jar package.hola

  • or In case of not in package

    java -cp /locationOfJar/hola.jar hola

Upvotes: 1

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