java - 将 Spring Java8 Junit 测试转换为 Kotlin 时摆脱 lateinit

Question

我正忙于将 Java8 Junit 测试转换为 Kotlin

Java8:

@ActiveProfiles("junit")
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath*:META-INF/spring/applicationContext.xml"})
public class AuctionTest {

    @Autowired
    AccountProcessor ap;

    @Test
    @Rollback
    public void securityTest(){

用Kotlin重写，看起来像这样:

@ActiveProfiles("junit")
@RunWith(SpringJUnit4ClassRunner::class)
@ContextConfiguration("classpath*:META-INF/spring/applicationContext.xml")
class AccountTest() {

    @Autowired
    lateinit var ap: AccountProcessor

    @Test
    @Rollback
    fun securityTest() {

上面的单元测试运行良好，但我想去掉 lateinit

像这样重写:

@ActiveProfiles("junit")
@RunWith(SpringJUnit4ClassRunner::class)
@ContextConfiguration("classpath*:META-INF/spring/applicationContext.xml")
class AccountTest(@Autowired val ap: AccountProcessor) {

    @Test
    @Rollback
    fun securityTest() {

Junit 提示

java.lang.Exception: Test class should have exactly one public zero-argument constructor

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.(SpringJUnit4ClassRunner.java:104) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:29) at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:21) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:26) at org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:31) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:96) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

有没有办法解决这个问题，还是我坚持使用 lateinit @Autowires ？

Answer 1

在 spring 组件注入(inject)处理器的情况下，你应该注释构造函数，而不是构造函数参数:

@Service
class AccountTest @Autowired constructor(val ap: AccountProcessor) {
}

Bit Junit 添加了他们对如何实现测试类的限制，并且不可能以您想要的方式注入(inject) bean。

附言。从 Spring 4.3 开始你不需要 @Autowired:

@Service
class AccountTest(val ap: AccountProcessor) {