使用 LogCaptor 测试 Logging

背景

在测试过程中，有的时候我们需要根据打出的日志来判断整个 process flow 是否正确。这就需要用到 LogCaptor 。

兼容性

支持 Java 8 和 Java 11+ 。

主流的 Logging framework 都支持。

• SLFJ4
• Logback
• Java Util Logging
• Apache Log4j
• Apache Log4j2
• Log4j with Lombok
• Log4j2 with Lombok
• SLFJ4 with Lombok
• Java Util Logging with Lombok

依赖

添加 Maven 依赖

<dependency>
    <groupId>io.github.hakky54</groupId>
    <artifactId>logcaptor</artifactId>
    <version>2.7.0</version>
    <scope>test</scope>
</dependency>

使用

服务类，会输出日志：

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class FooService {
    private static final Logger LOGGER = LogManager.getLogger(FooService.class);
    public void sayHello() {
		// do something 1
        LOGGER.info("process_1 finish");
		// do something 2
        LOGGER.warn("process_2 finish");
    }
}

测试类，验证日志信息：

import static org.assertj.core.api.Assertions.assertThat;

import nl.altindag.log.LogCaptor;
import org.junit.jupiter.api.Test;

public class FooServiceShould {

    @Test
    public void logInfoAndWarnMessages() {
        LogCaptor logCaptor = LogCaptor.forClass(FooService.class);

        FooService fooService = new FooService();
        fooService.sayHello();

        // Get logs based on level
        assertThat(logCaptor.getInfoLogs()).containsExactly("process_1 finish");
        assertThat(logCaptor.getWarnLogs()).containsExactly("process_2 finish");

        // Get all logs
        assertThat(logCaptor.getLogs())
                .hasSize(2)
                .contains(
                    "process_1 finish",
                    "process_2 finish"
                );
    }
}

参考

• Gitlab 源码地址： https://github.com/Hakky54/log-captor