在JAR文件中，URL getResource不起作用 [英] URL getResource not working when in JAR file

问题描述

我的应用程序加载了一个txt文件，该文件位于 PROJECTNAME / resource 文件夹中。

My application loads a txt file which is in PROJECTNAME/resource folder.

以下是我加载文件的方式：

Here is how I'm loading the file:

URL url = getClass().getClassLoader().getResource("batTemplate.txt");
java.nio.file.Path resPath;
String bat = "";

try {
    resPath = java.nio.file.Paths.get(url.toURI());
    bat = new String(java.nio.file.Files.readAllBytes(resPath), "UTF8");
} catch (URISyntaxException | IOException e1) {
        e1.printStackTrace();
}

注意：当我从Eclipse运行时这是有效的，当我导出到Jar文件（将生成的JAR中提取所需的lib。）时，不会。
我知道该文件正在被提取，因为它在JAR文件中。图像也有效。

NOTE: This works when I run from Eclipse, and doesn't when I Export to a Jar file (Extract required lib. into generated JAR). I know that the file is being extracted because its in the JAR file. Also the images work.

错误MSG：

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException:
    Illegal character in path at index 38: file:/C:/DataTransformation/Reports Program/ReportsSetup.jar
        at com.sun.nio.zipfs.ZipFileSystemProvider.uriToPath(ZipFileSystemProvider.java:87)
        at com.sun.nio.zipfs.ZipFileSystemProvider.getFileSystem(ZipFileSystemProvider.java:166)
        at com.sun.nio.zipfs.ZipFileSystemProvider.getPath(ZipFileSystemProvider.java:157)
        at java.nio.file.Paths.get(Unknown Source)
        at ReportSetup$13.mouseReleased(ReportSetup.java:794)

我也是看看这里的类似问题，但是它们引用了JAR文件之外的文件/ URL。

I also looked at the similar problem here, however they refer to file/URL outside JAR file.

推荐答案

.jar条目不是文件;它是.jar存档的一部分。无法将资源转换为Path。你需要使用 getResourceAsStream 来阅读它。

A .jar entry is not a file; it is part of the .jar archive. It is not possible to convert a resource to Path. You’ll want to read it using getResourceAsStream instead.

要阅读所有内容，你有几个选择。您可以使用扫描仪：

To read all of it, you have a few options. You can use a Scanner:

try (Scanner s = new Scanner(getClass().getClassLoader().getResourceAsStream("batTemplate.txt"), "UTF-8")) {
    bat = s.useDelimiter("\\Z").next();
    if (s.ioException() != null) {
        throw s.ioException();
    }
}

您可以将资源复制到临时文件：

You can copy the resource to a temporary file:

Path batFile = Files.createTempFile("template", ".bat");
try (InputStream stream = getClass().getClassLoader().getResourceAsStream("batTemplate.txt")) {
    Files.copy(stream, batFile);
}

您只需从InputStreamReader中读取文本：

You can simply read the text from an InputStreamReader:

StringBuilder text = new StringBuilder();
try (Reader reader = new BufferedReader(
    new InputStreamReader(
        getClass().getClassLoader().getResourceAsStream("batTemplate.txt"),
        StandardCharsets.UTF_8))) {

    int c;
    while ((c = reader.read()) >= 0) {
        text.append(c);
    }
}

String bat = text.toString();

这篇关于在JAR文件中，URL getResource不起作用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！