异常（堆栈跟踪）在springboot单元测试中不可用

Question

我开始使用 spring 启动框架，每一步都会出错。目前我有一个我完全不明白的情况。

我正在使用 spring boot 2.3。5.RELEASE 使用 maven 构建

    <properties>
        <java.version>11</java.version>
        <maven.compiler.source>${java.version}</maven.compiler.source>
        <maven.compiler.target>${java.version}</maven.compiler.target>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.5.RELEASE</version>
        <relativePath/>
        <!-- lookup parent from repository -->
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.hibernate.validator/hibernate-validator -->
        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>6.1.6.Final</version>
        </dependency>

        <!-- OpenAPi (swagger)-->
        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-ui</artifactId>
            <version>1.2.32</version>
        </dependency>

    </dependencies>

我创建了一个相当简单的 class REST 通信。没有@Component、@Controller 或类似的东西。

public class RESTCommunication {
    private final Logger m_logger = LoggerFactory.getLogger(this.getClass());
    private String m_contentType;
    private String m_path;    
    private String m_body;

    private HashMap<String,String> m_urlParams;
    private HashMap<String,String> m_queryParams;

    public RESTCommunication() {
    m_logger.debug("RESTCommunication constructor");
        
    m_scheme    = RESTCommunication.SCHEME_DEFAULT;
    m_authority = RESTCommunication.AUTHORITY_DEFAULT;
    m_port      = RESTCommunication.PORT_DEFAULT;
    m_path      = RESTCommunication.PATH_DEFAULT;

    m_urlParams = new HashMap<>();
    // m_queryParams = new HashMap<>();  // I know that this is the reason for the exception
}

@Override
public String toString() {
    StringBuilder sbToString = new StringBuilder();
    sbToString.append(buildURI());
    sbToString.append("|numURLParams:").append(m_urlParams.size());
    sbToString.append("|numQueryParams:").append(m_queryParams.size());  // This has to fail because m_queryParams is not initialized
    return sbToString.toString();
}
    .....

为此 class 我创建了一个非常简单的测试 class RESTCommunicationTest

@SpringBootTest
public class RESTCommunicationTest {
    private final Logger m_logger = LoggerFactory.getLogger(this.getClass());

    @Test
    public void defaultInitTest() {
        RESTCommunication restComm = new RESTCommunication();
  
        String restCommURL = restComm.toString();  // Expect the nullpointer INSIDE the toString method
        String expectedURL = sbExpected.toString();
        
        assertEquals(expectedURL, restCommURL, "Expected URL does not match generated");
    }

我运行用命令测试：$./mvnw -e -X package -Dtest=RESTCommunicationTest#defaultInitTest 正如预期的那样，我在标准输出日志记录中看到了 Nullpointer。但是在日志中我发现了这个：

webServerFactoryCustomizerBeanPostProcessor
websocketServletWebServerCustomizer
welcomePageHandlerMapping
[ERROR] Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 3.532 s <<< FAILURE! - in org.highpots.hippo.core.communication.RESTCommunicationTest
[ERROR] defaultInitTest  Time elapsed: 0.399 s  <<< ERROR!
java.lang.NullPointerException                                                                                                                                                                                                                                                    
    at org.ilovespringboot.not.RESTCommunicationTest.defaultInitTest(RESTCommunicationTest.java:36)

2020-12-08 22:18:10.810  INFO 10381 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
[INFO]
[INFO] Results:
[INFO]
[ERROR] Errors:
[ERROR]   RESTCommunicationTest.defaultInitTest:36 » NullPointer
[INFO]
[ERROR] Tests run: 1, Failures: 0, Errors: 1, Skipped: 0

RESTCommunicationTest.java:36 中的空指针。绝对没有暗示真正的 NullPointer 发生在 RESTCommunication class.
有人可以解释我的行为吗？我做错了什么吗？
我知道我是某种编程恐龙。（java 个项目大约是 10 多年以前的事了）。但我希望得到抛出异常的提示。我希望有一个由部分引起的详细堆栈跟踪。
如果无法想象这是不正常的行为。因为那意味着我必须通过完整的源代码逐步查找所有错误...这是不可能的

提前感谢您的帮助哈里·E

Answer 1

Maven 使用 surefire 插件运行 tests.To 请参阅异常堆栈跟踪，您必须将 trimStackTrace 设置为 false surefire插件配置。

历史上 surefire 插件用于打印完整的堆栈跟踪。尽管堆栈跟踪中的信息对调试很有用，但堆栈跟踪在控制台输出中占据了相当多的 space。特别是如果有很多失败的测试，很容易迷失在噪音中。

自 2.13 版本以来，surefire 默认只打印摘要。

    <build>
      <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>${your.maven.surefire.version.here}</version>
            <configuration>
                <trimStackTrace>false</trimStackTrace>
            </configuration>
        </plugin>
      </plugins>
    </build>

异常（堆栈跟踪）在springboot单元测试中不可用

Exception (stacktrace) not available in springboot unit test

java

exception

spring-boot

junit5