Resource files not found from JUnit test cases

问题:

Summary

My JUnit tests are not finding the files they require during execution. I'm using Maven for dependency management and compilation.

Details

All files required by the test cases are located in: src/test/resources.

For example, src/test/resources/resourceFile.txt.

To access a resource I use the following code:

URL url = getClass().getResource("/resourceFile.txt").getFile();
File file = new File(url);

But then file.exists() returns false. And the error I get is:

Tests in error: 
  myJUnitTestCase(tests.MyJUnitTestClass): /home/me/workspace/Project%20Name/target/test-classes/resourceFile.txt (No such file or directory)

Note, the following gives the same error (notice the removed / prefix):

URL url = getClass().getClassLoader().getResource("resourceFile.txt").getFile();
File file = new File(url);

It seems as though the files from src/test/resources are not getting copied into target/test-classes.

Any ideas?

The following questions did not help

Why Can't I access src/test/resources in Junit test run with Maven?

Loading Properties File In JUnit @BeforeClass

How to deal with the test data in Junit?

Software Versions

Ubuntu 12.04

Apache Maven 2.2.1

Java 1.7.0

Eclipse (Java EE IDE for Web Developers) Indigo Service Release 2

(truncated) Maven POM

<?xml version="1.0" encoding="UTF-8"?>
<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.groupId</groupId>
    <artifactId>artifactId</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>name</name>
    <build>
        <finalName>name</finalName>
        <directory>target</directory>
        <outputDirectory>target/classes</outputDirectory>
        <testOutputDirectory>target/test-classes</testOutputDirectory>
        <sourceDirectory>src/main/java</sourceDirectory>
        <testSourceDirectory>src/test/java</testSourceDirectory>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
        </resources>
        <testResources>
            <testResource>
                <directory>src/test/resources</directory>
            </testResource>
        </testResources>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

回答1:

My mistake, the resource files WERE actually copied to target/test-classes. The problem seemed to be due to spaces in my project name, e.g. Project%20Name.

I'm now loading the file as follows and it works:

org.apache.commons.io.FileUtils.toFile(myClass().getResource("resourceFile.txt")‌​);

Or, (taken from Java: how to get a File from an escaped URL?) this may be better (no dependency on Apache Commons):

myClass().getResource("resourceFile.txt")‌​.toURI();

回答2:

You know that Maven is based on the Convention over Configuration pardigm? so you shouldn't configure things which are the defaults.

All that stuff represents the default in Maven. So best practice is don't define it it's already done.

    <directory>target</directory>
    <outputDirectory>target/classes</outputDirectory>
    <testOutputDirectory>target/test-classes</testOutputDirectory>
    <sourceDirectory>src/main/java</sourceDirectory>
    <testSourceDirectory>src/test/java</testSourceDirectory>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
        </resource>
    </resources>
    <testResources>
        <testResource>
            <directory>src/test/resources</directory>
        </testResource>
    </testResources>

回答3:

This is actually redundant except in cases where you want to override the defaults. All of these settings are implied defaults.

You can verify that by checking your effective POM using this command

mvn help:effective-pom

    <finalName>name</finalName>
    <directory>target</directory>
    <outputDirectory>target/classes</outputDirectory>
    <testOutputDirectory>target/test-classes</testOutputDirectory>
    <sourceDirectory>src/main/java</sourceDirectory>
    <testSourceDirectory>src/test/java</testSourceDirectory>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
        </resource>
    </resources>
    <testResources>
        <testResource>
            <directory>src/test/resources</directory>
        </testResource>
    </testResources>

For example, if i want to point to a different test resource path or resource path you should use this otherwise you don't.

    <resources>
        <resource>
            <directory>/home/josh/desktop/app_resources</directory>
        </resource>
    </resources>
    <testResources>
        <testResource>
            <directory>/home/josh/desktop/test_resources</directory>
        </testResource>
    </testResources>