使用 junit test 将命令行参数传递给 Spring Boot 应用程序

Question

新手上路，请多包涵

我有一个非常基本的 Spring Boot 应用程序，它需要来自命令行的参数，没有它就无法工作。这是代码。

 @SpringBootApplication
public class Application implements CommandLineRunner {

    private static final Logger log = LoggerFactory.getLogger(Application.class);

    @Autowired
    private Reader reader;

    @Autowired
    private Writer writer;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Override
    public void run(String... args) throws Exception {

        Assert.notEmpty(args);

        List<> cities = reader.get("Berlin");
         writer.write(cities);
    }
}

这是我的 JUnit 测试类。

 @RunWith(SpringRunner.class)
@SpringBootTest
public class CityApplicationTests {

    @Test
    public void contextLoads() {
    }
}

现在， Assert.notEmpty() 要求传递参数。但是，现在，我正在为此编写 JUnit 测试。但是，我从 Assert 得到以下异常引发。

 2016-08-25 16:59:38.714 ERROR 9734 --- [           main] o.s.boot.SpringApplication               : Application startup failed

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:801) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:782) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:769) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:111) [spring-boot-test-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.boot.test.autoconfigure.AutoConfigureReportTestExecutionListener.prepareTestInstance(AutoConfigureReportTestExecutionListener.java:46) [spring-boot-test-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) [.cp/:na]
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) [.cp/:na]
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) [.cp/:na]
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678) [.cp/:na]
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) [.cp/:na]
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) [.cp/:na]
Caused by: java.lang.IllegalArgumentException: [Assertion failed] - this array must not be empty: it must contain at least 1 element
    at org.springframework.util.Assert.notEmpty(Assert.java:222) ~[spring-core-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at org.springframework.util.Assert.notEmpty(Assert.java:234) ~[spring-core-4.3.2.RELEASE.jar:4.3.2.RELEASE]
    at com.deepakshakya.dev.Application.run(Application.java:33) ~[classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:798) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
    ... 32 common frames omitted

任何想法，如何传递参数？