java.lang.IllegalArgumentException: name

问题

"it work fine in eclipse but when i create jar and run it will give me this exception.This is non web spring boot application i am using which i supposed to run as standalone jar"

java.lang.IllegalArgumentException: name
                    at sun.misc.URLClassPath$Loader.findResource(Unknown Source) ~[na:1.8.0_171]



at sun.misc.URLClassPath.findResource(Unknown Source) ~[na:1.8.0_171]
                    at java.net.URLClassLoader$2.run(Unknown Source) ~[na:1.8.0_171]
                    at java.net.URLClassLoader$2.run(Unknown Source) ~[na:1.8.0_171]
                    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_171]
                    at java.net.URLClassLoader.findResource(Unknown Source) ~[na:1.8.0_171]
                    at org.springframework.boot.loader.LaunchedURLClassLoader.findResource(LaunchedURLClassLoader.java:58) ~[extension-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
                    at java.lang.ClassLoader.getResource(Unknown Source) ~[na:1.8.0_171]
                    at java.net.URLClassLoader.getResourceAsStream(Unknown Source) ~[na:1.8.0_171]

回答1:

It might be a bit late but I encounted the same error recently on Windows and fixed it with a dirtly hack. I hope future people looking for the same question will find this useful for their problem.

First of all, eclipse "run" your Spring Boot app in a different way. It does not do java -jar foo.jar but reference all classes and libraries directly i.e. java -classpath xxx/target/classes:a.jar:b.jar.... So soetimes running in eclipse will behave differently.

I suppose you are running into the same situtation as I did which is you have a Spring Boot app and you want to package it as executable jar and you are referencing external dependencies and could not fix what went wrong inside those external dependencies.

What I found out was that somewhere inside the external library I was using is generating a temporary file and reading it using Java's ClassLoader but Spring Boot's LaunchedURLClassLoader could not handle Windows's "x:\" syntax

In my case, it was

URL findResource(name): C:\foo\bar.xml

So the hack is to build your own LaunchedURLClassLoader and replace it in the executable jar. If you unpack the excutable jar, you will find LaunchedURLClassLoader.class under org\springframework\boot\loader. The idea is to reaplce C:\foo\bar.xml to file:///C:/foo/bar.xml so Java ClassLoader will know how to deal with the file.

...

package org.springframework.boot.loader;
...

public class LaunchedURLClassLoader extends URLClassLoader {

    ...

    @Override
    public URL findResource(String name) {

        // This is where I added the dirty hack
        if (name.contains(":\\") && !name.startsWith("file:///")) {
            System.out.println("URL findResource(name): " + name); // just for you to debug
            name = "file:///" + name.replace("\\", "/");
            System.out.println("URL findResource(name): Reaplced to " + name); // just for you to debug
        }

        Handler.setUseFastConnectionExceptions(true);
        try {
            return super.findResource(name);
        }
        finally {
            Handler.setUseFastConnectionExceptions(false);
        }
    }
    ....
}

来源：https://stackoverflow.com/questions/51203893/java-lang-illegalargumentexception-name

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java

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spring-mvc

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