无法从目录加载类。与罐子同时可以在罐子解压缩/解压时加载类

发布于 2024-12-06 00:43:01 字数 1229 浏览 0 评论 0原文

社区！如果您能帮助我解决我的问题，那就太好了。

我有一个自定义类加载器，它将是 java.system.class.loader - 它包含 urls 哪里可以找到课程。像这样：

public class TestSystemClassLoader extends URLClassLoader {

    public TestSystemClassLoader(ClassLoader parent) {
    super(classpath(), parent);
    }

    private static URL[] classpath() {
    try {
        // I got junit-4.8.2.jar under this url.
        URL url = new File("D:\\Work\\lib\\junit-4\\").toURI().toURL();
        return new URL[] { url };
    }
    catch (MalformedURLException e) {
        throw new IllegalArgumentException(e);
    }
    }
}

然后我用 -Djava.system.class.loader=TestSystemClassLoader eg.TestMain 运行 java(JDK6)，其中eg.TestMain' main：

public static void main(String[] args) throws Exception {
    // here I got system CL which is what I want.
ClassLoader cl = Thread.currentThread().getContextClassLoader();
    // here I got: "Exception in thread "main" java.lang.ClassNotFoundException: org.junit.runners.JUnit4"
Class<?> clazz = Class.forName("org.junit.runners.JUnit4", true, cl);
}

让我生气的是，如果我解压/解压缩/解压 junit-4.8.2.jar - 那么例如，TestMain 可以工作！

问题是 - 如何告诉 java(JDK6) 我希望整个目录位于类路径中，即驻留在目录中的任何文件。

提前致谢！

原文

community! Would be great if u could help me w/ my issue.

I got a custom class loader which is gonna to be java.system.class.loader - it holds
urls where to find classes. Like this:

public class TestSystemClassLoader extends URLClassLoader {

    public TestSystemClassLoader(ClassLoader parent) {
    super(classpath(), parent);
    }

    private static URL[] classpath() {
    try {
        // I got junit-4.8.2.jar under this url.
        URL url = new File("D:\\Work\\lib\\junit-4\\").toURI().toURL();
        return new URL[] { url };
    }
    catch (MalformedURLException e) {
        throw new IllegalArgumentException(e);
    }
    }
}

Then I run the java(JDK6) with -Djava.system.class.loader=TestSystemClassLoader eg.TestMain,
where eg.TestMain' main:

public static void main(String[] args) throws Exception {
    // here I got system CL which is what I want.
ClassLoader cl = Thread.currentThread().getContextClassLoader();
    // here I got: "Exception in thread "main" java.lang.ClassNotFoundException: org.junit.runners.JUnit4"
Class<?> clazz = Class.forName("org.junit.runners.JUnit4", true, cl);
}

The thing which makes me mad is that if I unpack/unzip/unjar the junit-4.8.2.jar - then
eg.TestMain would work!

The question is - how to tell java(JDK6) that I want whole directory to be in classpath,
i.e. any file residing in the directory.

Thanks in advance!

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

寄风 2024-12-13 00:43:01

找到所有罐子并添加它们：

private static URL[] classpath() {
    try {
        File file = new File("D:\\Work\\lib\\junit-4\\");
        List<URL> urls = new ArrayList<URL>();
        for (File f : file.listFiles()) {
            if (f.isFile() && f.getName().endsWith(".jar")) {
                urls.add(f.toURI().toURL());
            }
        }

        return urls.toArray(new URL[0]);
    }
    catch (MalformedURLException e) {
        throw new IllegalArgumentException(e);
    }
}

Find all the jars and add them:

private static URL[] classpath() {
    try {
        File file = new File("D:\\Work\\lib\\junit-4\\");
        List<URL> urls = new ArrayList<URL>();
        for (File f : file.listFiles()) {
            if (f.isFile() && f.getName().endsWith(".jar")) {
                urls.add(f.toURI().toURL());
            }
        }

        return urls.toArray(new URL[0]);
    }
    catch (MalformedURLException e) {
        throw new IllegalArgumentException(e);
    }
}

回复收藏 0 原文

~没有更多了~