class 的模拟方法

Question

运行 junit

时出现异常

class JSONTool {
    private static MipLogger logger = MipLogger.getLogger(MIPJsonTool.class);

    public Object fetch(String url) {
        return invokeEndPoint(url, 2000, new HashMap<String, String>());
    }
}

我想测试这个class 下面是测试方法

public void testFetchString() {
    JSONTool mipJsonTool = new JSONTool();
    JSONTool mipJsonTool1 = Mockito.spy(mipJsonTool);       
    Mockito.doReturn(new JSONObject()
            .put("status", 200))
            .when(mipJsonTool1)
            .fetch("http://localhost:5000/author");
    Object obj = mipJsonTool1.fetch("http://localhost:5000/author");
    System.out.println("Done!");
}

运行 junit 给出以下异常

java.lang.NoClassDefFoundError: org/apache/logging/log4j/util/ReflectionUtil Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.util.ReflectionUtil

Answer 1

NoClassDefFoundError 是当 Java 运行时系统尝试加载 class 的定义时抛出的错误，并且 class 定义不再可用。所需的 class 定义在编译时存在，但在运行时缺失。

检查您使用的记录器配置和 jar。

同时您可以为 org.apache.logging.log4j.util.ReflectionUtil

提供缺少的依赖项

将 log4j 版本更改为 2.8.2 看看是否有帮助

//编辑后的版本

我已经创建了一个具有以下配置的项目来使记录器工作

build.gradle

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java Library project to get you started.
 * For more details take a look at the Java Libraries chapter in the Gradle
 * user guide available at https://docs.gradle.org/5.0/userguide/java_library_plugin.html
 */

plugins {
    // Apply the java-library plugin to add support for Java Library
    id 'java-library'
}

repositories {
    // Use jcenter for resolving your dependencies.
    // You can declare any Maven/Ivy/file repository here.
    jcenter()
}

dependencies {
    // This dependency is exported to consumers, that is to say found on their compile classpath.
    api 'org.apache.commons:commons-math3:3.6.1'
    api 'org.apache.logging.log4j:log4j-web:2.8.2'

    // This dependency is used internally, and not exposed to consumers on their own compile classpath.
    implementation 'com.google.guava:guava:26.0-jre'


    // Use JUnit test framework
    testImplementation 'junit:junit:4.12'
}

在 src/main/resources 下创建一个 log4j2.properties 文件，其中包含以下条目以向控制台显示日志

appender.console.type = Console
appender.console.name = STDOUT


rootLogger.level = debug
rootLogger.appenderRefs = stdout
rootLogger.appenderRef.stdout.ref = STDOUT

下面是调用记录器的 Java 代码（为了测试，我把它放在 main 方法中）

package GradleEclipseTestProject;

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

public class GradleLog4jTest {


    public static void main(String[] args) {
        System.out.println("Testing log4j dependencies");
        Logger logger = LogManager.getLogger();
        logger.info("This is a sample logger");
    }

}

class 的模拟方法

mocking method of class

java

junit

log4j

mocking