Cannot build project when special character presents in the path of the project

[haijian-vaadin]

Description of the bug / feature

Got the following error when trying to run/build an application whose path has a special character.

[ERROR] Failed to execute goal com.vaadin:vaadin-maven-plugin:22.0.0.alpha3:prepare-frontend (default) on project special-character: Could not execute prepare-frontend goal.: Cannot invoke "String.replace(char, char)" because "path" is null -> [Help 1]

Minimal reproducible example

1. Create a folder which has special characters, e.g. äbc
2. Download a Vaadin 22 Flow starter project (could just use the default one)
3. Put the zip file into the äbc folder, unzip and run the application

Expected behavior

The application runs

Actual behavior

Got the above mentioned error message and the application cannot start

Versions:

- Vaadin / Flow version: Vaadin 22 alpha3
- Java version: openJDK Runtime Environment Corretto-16.0.1.9.1 (build 16.0.1+9)
- OS version: macOs big sur 11.5.2

[mshabarov]

Steps 1-3 give me a bit different errors:

My project directory name is special-chars-äbc.

when running with mvn:

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.5.4:run (default-cli) on project special-char: Could not exec java: Cannot run program "/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home/jre/bin/java" (in directory "/Users/mikhail/workspace/vaadin/starters/special-chars-?bc/special-char"): error=2, No such file or directory -> [Help 1]

when running with Run 'Application' in IntellijIDEA:

2021-09-21 10:21:47.717 ERROR 2668 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Exception sending context initialized event to listener instance of class [com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener]

java.lang.RuntimeException: Unable to initialize com.vaadin.flow.spring.VaadinServletContextInitializer$VaadinAppShellContextListener
	at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:193) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.lambda$contextInitialized$0(VaadinServletContextInitializer.java:210) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
	at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.contextInitialized(VaadinServletContextInitializer.java:210) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4766) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5230) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:450) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:199) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.4.jar:2.5.4]
	at com.example.application.Application.main(Application.java:27) ~[classes/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.5.4.jar:2.5.4]
Caused by: java.lang.IllegalStateException: Parent resource of [/Users/mikhail/workspace/vaadin/starters/special-chars-äbc/special-char/target/classes/com/example/application/Application.class] not found in the resources!
	at com.vaadin.flow.spring.VaadinServletContextInitializer$CustomResourceLoader.collectResources(VaadinServletContextInitializer.java:845) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at com.vaadin.flow.spring.VaadinServletContextInitializer$CustomResourceLoader.getResources(VaadinServletContextInitializer.java:815) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.scanCandidateComponents(ClassPathScanningCandidateComponentProvider.java:420) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:315) ~[spring-context-5.3.9.jar:5.3.9]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195) ~[na:na]
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[na:na]
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578) ~[na:na]
	at com.vaadin.flow.spring.VaadinServletContextInitializer$VaadinAppShellContextListener.failFastContextInitialized(VaadinServletContextInitializer.java:553) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:189) ~[vaadin-spring-19.0.0.alpha1.jar:na]
	... 46 common frames omitted

[martinfrancois]

I can still reproduce this class of path issue with current Vaadin 25.x.

The failure is reproducible on macOS when the project path contains a decomposed Unicode character, specifically c plus combining cedilla (U+0063 U+0327). The same minimal project passes from an ASCII path and from a path containing only a regular space.

This looks related to the older reports in #8191 and #18445, but those are closed. I am adding this here instead of opening a duplicate because this issue is still open and an earlier comment already shows the same Parent resource of [...] not found in the resources! failure class.

Reproduction

Create a minimal Vaadin Spring Boot project:

<!-- pom.xml -->
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>4.0.6</version>
        <relativePath/>
    </parent>

    <groupId>com.example</groupId>
    <artifactId>vaadin-path-repro</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <properties>
        <java.version>25</java.version>
        <vaadin.version>25.1.4</vaadin.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-bom</artifactId>
                <version>${vaadin.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-dev</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-maven-plugin</artifactId>
                <version>${vaadin.version}</version>
            </plugin>
        </plugins>
    </build>
</project>

// src/main/java/com/example/application/Application.java
package com.example.application;

import com.vaadin.flow.component.page.AppShellConfigurator;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application implements AppShellConfigurator {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

// src/main/java/com/example/application/MainView.java
package com.example.application;

import com.vaadin.flow.component.html.Div;
import com.vaadin.flow.router.Route;

@Route("")
public class MainView extends Div {
    public MainView() {
        setText("Hello");
    }
}

// src/test/java/com/example/application/ApplicationTest.java
package com.example.application;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
class ApplicationTest {
    @Test
    void contextLoads() {
    }
}

Then run the same project from different paths:

# Baseline ASCII path: passes
cd /tmp/vaadin-path-repro
mvn -q test

# Path containing only a regular space: also passes
cp -R /tmp/vaadin-path-repro "/tmp/vaadin space only"
cd "/tmp/vaadin space only"
mvn -q test

# Path containing decomposed Unicode: fails
python3 - <<'PY'
import shutil
from pathlib import Path

src = Path("/tmp/vaadin-path-repro")
dst = Path("/tmp") / "vaadin-c\u0327-repro"
shutil.rmtree(dst, ignore_errors=True)
shutil.copytree(src, dst)
print(dst)
PY

cd "$(python3 - <<'PY'
from pathlib import Path
print(Path("/tmp") / "vaadin-c\u0327-repro")
PY
)"
mvn -q test

Actual result

The decomposed Unicode path fails during Spring Boot test context startup:

java.lang.RuntimeException: Unable to initialize com.vaadin.flow.spring.VaadinServletContextInitializer$VaadinAppShellContextListener
...
Caused by: java.lang.IllegalStateException: Parent resource of [/private/tmp/vaadin-c%CC%A7-repro/target/test-classes/com/example/application/ApplicationTest.class] not found in the resources!
    at com.vaadin.flow.spring.VaadinServletContextInitializer$CustomResourceLoader.collectResources(VaadinServletContextInitializer.java:1098) ~[vaadin-spring-25.1.4.jar:na]
    at com.vaadin.flow.spring.VaadinServletContextInitializer$CustomResourceLoader.getResources(VaadinServletContextInitializer.java:1034) ~[vaadin-spring-25.1.4.jar:na]

The encoded %CC%A7 is the combining cedilla in the path.

Expected result

The application should start from the decomposed Unicode path in the same way it starts from the ASCII path and the path containing only a regular space.

Versions

• Vaadin / Flow version: reproduced with 25.1.3 and 25.1.4
• Java version: Azul Zulu 25.0.1
• Maven version: 3.9.11
• OS version: macOS 26.3.1, Apple Silicon
• Browser version: n/a
• Application server: embedded Tomcat 11.0.21 via Spring Boot 4.0.6

Related issues

• Vaadin project won't start from a path containing a letter ě #8191 reported a similar path encoding problem and was closed as not reproducible in Vaadin 23.3.
• Production JAR not running on a folder with space #18445 reported a space-in-path production JAR issue and was closed after maintainers could not reproduce it.
• Parent resource of [.../target/classes/com/example/application/views/MyView.class] not found in the resources! #18730 had the same error message but was tied to dev-mode reload/cache behavior and was fixed in fix: fix cache resource validation on application reload #18754.

AI assistance disclosure: I used an AI assistant to help reproduce the issue, compare it against existing reports, and draft this comment. I reviewed the reproduction result and content before submitting.