Maven没有找到org.junit，即使它位于依赖项中

Question

我想在我的小项目中添加一个测试（请注意我从代码和更改的软件包名称中删除了一些内容，因此，如果您看到有关此问题的任何错误，可能不是这个;））：

package my.pckg;


import static org.junit.Assert.*;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;


public class SignedRequestCallbackTest {


    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void testCorrectSignedRequest() {
        assertTrue(false);
    }

}

（我也尝试从TestCase扩展以删除静态导入，但它没有帮助）

运行mvn test后，它显示了一个无法找到的错误org.junit：

[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Test Server 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:2.4.3:resources (default-resources) @ server ---
[WARNING] Using platform encoding (MacRoman actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:2.3.2:compile (default-compile) @ server ---
[WARNING] File encoding has not been set, using platform encoding MacRoman, i.e. build is platform dependent!
[INFO] Compiling 9 source files to /Users/michael/Projects/fbmuc/server/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[4,27] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[6,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[7,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[8,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[14,9] cannot find symbol
symbol  : class Before
location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[18,9] cannot find symbol
symbol  : class After
location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[22,9] cannot find symbol
symbol  : class Test
location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[24,12] cannot find symbol
symbol  : method assertTrue(boolean)
location: class my.pckgSignedRequestCallbackTest
[INFO] 9 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.161s
[INFO] Finished at: Fri Feb 22 18:02:37 CET 2013
[INFO] Final Memory: 8M/81M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project server: Compilation failure: Compilation failure:
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[4,27] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[4,4] static import only from classes and interfaces
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[6,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[7,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[8,16] package org.junit does not exist
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[14,9] cannot find symbol
[ERROR] symbol  : class Before
[ERROR] location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[18,9] cannot find symbol
[ERROR] symbol  : class After
[ERROR] location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[22,9] cannot find symbol
[ERROR] symbol  : class Test
[ERROR] location: class my.pckgSignedRequestCallbackTest
[ERROR] ~/code/src/test/java/my/pckg/SignedRequestCallbackTest.java:[24,12] cannot find symbol
[ERROR] symbol  : method assertTrue(boolean)
[ERROR] location: class my.pckgSignedRequestCallbackTest
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

我的pom.xml看起来像这样：

<?xml version="1.0" encoding="UTF-8"?>
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>TestServer</name>
    <description>Test</description>
    <build>
        <sourceDirectory>src</sourceDirectory>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <!-- Facebook library -->
        <dependency>
            <groupId>com.restfb</groupId>
            <artifactId>restfb</artifactId>
            <version>1.6.11</version>
        </dependency>
        <!-- Gson: Java to Json conversion -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.2.2</version>
            <scope>compile</scope>
        </dependency>
        <!-- Tigase server snapshot -->
        <dependency>
            <groupId>tigase</groupId>
            <artifactId>tigase-server</artifactId>
            <version>5.2.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <repositories>
        <repository>
            <id>tigase</id>
            <name>Tigase repository</name>
            <url>http://maven.tigase.org</url>
        </repository>
        <repository>
            <id>tigase-snapshot</id>
            <name>Tigase repository</name>
            <url>http://build.xmpp-test.net/maven/</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>

mvn依赖：tree：

[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Test Server 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ server ---
[INFO] my.pckg:server:jar:0.0.1-SNAPSHOT
[INFO] +- com.restfb:restfb:jar:1.6.11:compile
[INFO] +- com.google.code.gson:gson:jar:2.2.2:compile
[INFO] +- tigase:tigase-server:jar:5.2.0-SNAPSHOT:compile
[INFO] |  +- tigase:tigase-utils:jar:3.4.1-SNAPSHOT:compile
[INFO] |  \- tigase:tigase-xmltools:jar:3.4.3-SNAPSHOT:compile
[INFO] +- commons-codec:commons-codec:jar:1.7:compile
[INFO] \- junit:junit:jar:4.11:test
[INFO]    \- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.240s
[INFO] Finished at: Fri Feb 22 18:07:55 CET 2013
[INFO] Final Memory: 5M/81M
[INFO] ------------------------------------------------------------------------

mvn版本：

Apache Maven 3.0.3 (r1075438; 2011-02-28 18:31:09+0100)
Maven home: /usr/share/maven
Java version: 1.6.0_41, vendor: Apple Inc.
Java home: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
Default locale: de_CH, platform encoding: MacRoman
OS name: "mac os x", version: "10.8.2", arch: "x86_64", family: "mac"

请注意，我不是java或maven的专家，只是刚开始（尤其是maven）。 从我从其他文章和问题中看到的，我应该在src/test/java内进行我的测试，在src/main/java内进行我的“真实”代码 - 我这样做了。

此外，我删除了整个〜/ .m2 /文件夹，但它仍然无效。

我也跑了mvn test -X，但它对我没有帮助。如果我发帖请告诉我。

Answer 1

除非您有充分理由，否则不应覆盖POM <sourceDirectory>元素中的<build>设置。此属性确定Maven查找非测试代码的位置。此属性的默认值为src/main/java。 <testSourceDirectory>属性设置 test 代码的路径（默认为src/test/java。通过将<sourceDirectory>设置为src，Maven认为整个包含主应用程序代码的目录。由于src目录包含src/test/java，Maven然后尝试将测试代码编译为主应用程序的一部分。

这很重要，因为在编译主应用程序时（在compile阶段），Maven忽略了test范围的依赖关系。在主编译之后，测试代码在单独的阶段（test-compile阶段）编译。

因此，由于Maven尝试将测试代码编译为主应用程序的一部分，因此它省略了junit依赖项，并且它们在类路径中不可用。这里的解决方案是不在POM中指定<sourceDirectory>元素。

Answer 2

默认情况下，maven分别查看java和测试类的这些文件夹 - src / main / java和src / test / java

当在源代码下使用测试类指定src并且在pom.xml中提到junit依赖的范围时，maven将找不到test-org.unit。

Answer 3

只需将图像放在@matts Answer上，其他人就很容易纠正问题。

<sourceDirectory>src</sourceDirectory>

只需删除或注释 pom.xml

中存在的这一行

<!--  <sourceDirectory>src</sourceDirectory> !-->

有关解释，请仔细阅读@matt的答案