我的可执行jar无法在Netbeans之外运行时打开资源文件 [英] My executable jar can't open resource files when I run it outside of netbeans

问题描述

在这里的第一篇文章，我希望我已经适当地提出了这个问题.我的项目在netbeans内部作为项目运行时在类路径上找到资源文件，但是当我在netbeans外部运行jar时，它找不到资源(我已经检查过，是的，它们正在放入jar中. )

first post here, I hope I've formed this question adequately. My project finds the resource files on the classpath when run inside of netbeans as a project, but when I run the jar outside of netbeans, it can't find the resources (I have checked, and yes they are being placed into the jar.)

我已经尝试了.getResource()和我的代码的.getResourceAsStream()版本.当它们作为一个Maven项目在netbeans内部运行时，它们都成功，但是当我删除jar并将其在netbeans外部运行时，找不到这些资源.

I've tried both .getResource() and also a .getResourceAsStream() version of my code. They both succeed when run inside of netbeans as a maven project, but those resources aren't being found when I remove the jar and run it outside of netbeans.

这是我的代码的摘录，也是我添加资源的pom文件中的摘录.当在netbeans中作为项目运行时，所有方法均有效，但在其他地方运行jar时，则无效.它找不到资源.

Here's a snippet of my code, and also the snippet from my pom file where I add the resources. It all works when run as a project inside netbeans, but not when I run the jar elsewhere. It fails to find the resources.

......

    String wholeFile = "";
    try {

       BufferedReader objReader = new BufferedReader(
                new java.io.InputStreamReader(
                        getClass().getResourceAsStream( sqlFileName ) 
            )
        );

        StringBuilder sb = new StringBuilder();
        String strCurrentLine;
        while ( (strCurrentLine = objReader.readLine()) != null ) {
            sb.append( strCurrentLine );
            sb.append( System.getProperty("line.separator") );
        }
        wholeFile = sb.toString();

...或者最好是...

... or, preferably ...

        wholeFile = java.nio.file.Files.readString(
            java.nio.file.Paths.get( 
                getClass().getClassLoader().getResource( sqlFileName ).toURI()
            ) 
        );


    // Split that file into individual create
    // table strings contained in the file.

    // Slit on two newlines.
        String newLine = System.getProperty("line.separator");
        String[] tables = wholeFile.split( newLine + newLine );

......

这是我添加到pom中的内容.但这只能在netbeans中运行才能解决.为什么?我对这里的Maven设置缺少什么?在netbeans之外...可执行jar将无法像在netbeans中运行时那样定位这些资源文件.

And here's what I added to the pom. But this only resolves if run in netbeans. Why? What am I missing about the maven setup here? Outside of netbeans ... the executable jar won't locate these resource file like they do when run inside netbeans.

先谢谢了.我希望我的问题很清楚.

Thanks in advance. I hope my question was clear.

<resources>
    <resource>
        <directory>src/my-resources</directory>
            <includes>
                <include>**/*.txt</include>
                <include>**/*.jpg</include>
            </includes>
    </resource>
</resources>

据我所知，

推荐答案

java.nio.file.Files无法读取* .jar文件的内容.您需要通过类加载器作为流访问资源.因此，我认为您的第一次尝试应该没问题.

java.nio.file.Files cannot read the content of *.jar files, as far as I know. You need to access the resource via the class loader as stream. So I think your first attempt should be Ok.

可能只是路径名的问题.这是一个没有Maven的工作示例:

It's possibly just a matter of the path name. Here is a working example without Maven:

文件src/de/stefanfrings/Main.java:

File src/de/stefanfrings/Main.java:

package de.stefanfrings;

import java.io.InputStream;
import java.util.*;

public class Main
{
    public static void main(String[] args)
    {
        InputStream stream=Main.class.getResourceAsStream("/test.txt");
        Scanner in=new Scanner(stream);
        while (in.hasNextLine())
        {
            System.out.println(in.nextLine());
        }
        in.close();
    }
}

文件src/de/test.txt:

File src/de/test.txt:

Hello
World

test.jar的内容:

Content of test.jar:

META-INF/MANIFEST.MF
test.txt
de/stefanfrings/Main.class

输出:

java -jar test.jar
Hello
World

如果将文件名更改为"../../test.txt"，则它仅在IDE中有效，因为IDE从编译器放置其输出的(未压缩)文件夹中执行程序.

If I change the filename to "../../test.txt" then it works only in the IDE because the IDE executes the program from the (uncompressed) folder where the compiler places its output.

尝试为文件名加上"/"前缀.

Try to prefix your filename with "/".

这篇关于我的可执行jar无法在Netbeans之外运行时打开资源文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！