java.lang.UnsupportedOperationException：删除

Question

我正在构建一个带有 spring 引导的 ATM，并且我正在尝试在模拟存储库中包含一些测试。 但是当我尝试使用我的一种测试方法时，我得到了“java.lang.UnsupportedOperationException：remove”错误。 我是新手，所以我真的不明白为什么会这样。

不起作用的是withdrawOneThousand() 测试方法。 getAllBills() 测试方法工作正常。

在我在测试 class 中制作模拟存储库之前，我直接在数据库上尝试了测试方法，效果很好。

我的 controller：

@RestController
@RequestMapping("/bills")
public class BillController {

    private int calculate;

    @Autowired
    private BillRepository billRepository;



    @GetMapping(path = "/withdraw2/{value}")
    public String withdraw2(@PathVariable int value){
        List<Bill> billsToWithdraw = new ArrayList<>();
        List<Bill> dbCopy = (List<Bill>) billRepository.findAll();
        calculate = value;
        System.out.println("calc start " + calculate);

        try {
            while (calculate != 0) {

                if (calculate >= 1000 && searchBillList(1000, dbCopy)) {
                    billTransfer(1000, billsToWithdraw, dbCopy);

                } else if (calculate >= 500 && searchBillList(500, dbCopy)) {
                    billTransfer(500, billsToWithdraw, dbCopy);

                } else if (calculate >= 100 && searchBillList(100, dbCopy)) {
                    billTransfer(100, billsToWithdraw, dbCopy);

                }
                else {
                    return "No bills left";
                }
            }

            deleteFromDB(billsToWithdraw);

            System.out.println("returning");
            return "Bills: " + billsToWithdraw;

        } catch (NullPointerException e) {
            System.out.println(e);
            return "Not enough bills";
        } catch (Exception e){
            return e.toString();
        }

    }


    public void deleteFromDB(List<Bill> billsToWithdraw){
        billsToWithdraw.forEach((bill) -> billRepository.delete(bill));
    }

    public Boolean searchBillList(int valueToCheck, List<Bill> tempList) {
        return tempList.stream().anyMatch((bill -> bill.getValue() == valueToCheck));
    }

    public void billTransfer(int value, List<Bill> billsToWithdraw, List<Bill> tempList){
        Bill bill = tempList.stream().filter((currentBill) -> currentBill.getValue() == value).findFirst().get();
        calculate = calculate - bill.getValue();
        billsToWithdraw.add(bill);
        tempList.remove(bill);
    }

我的存储库：

public interface BillRepository extends CrudRepository<Bill, Long> {
    Iterable<Bill> findByValue(int value);
}

我的测试：

@SpringBootTest
@AutoConfigureMockMvc
public class BillControllerTest2 {

    @Autowired
    private MockMvc mvc;

    @MockBean
    private BillRepository mockRepo;

    @BeforeEach
    public void init(){
        Bill b1 = new Bill(1000, 1L);
        Bill b2 = new Bill(500, 2L);
        Bill b3 = new Bill(100, 3L);
        when(mockRepo.findByValue(1000)).thenReturn(List.of(b1));
        when(mockRepo.findByValue(500)).thenReturn(Arrays.asList(b2));
        when(mockRepo.findByValue(100)).thenReturn(Arrays.asList(b3));
        when(mockRepo.findAll()).thenReturn(Arrays.asList(b1, b2, b3));
    }

    @Test
    public void withdrawOneThousand() throws Exception {

        mvc.perform(MockMvcRequestBuilders.get("/bills/withdraw2/1000").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().string("Bills: [Bill{id=1, number=1000}]"));
    }

    @Test
    public void getAllBills() throws Exception {
        mvc.perform(MockMvcRequestBuilders.get("/bills/all").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().json("[{\"id\": 1, \"value\": 1000}, " +
                        "{\"id\": 2, \"value\": 500 }, " +
                        "{\"id\": 3, \"value\": 100}]"));
    }

我得到的错误：

java.lang.AssertionError: Response content expected:<Bills: [Bill{id=1, number=1000}]> but was:<java.lang.UnsupportedOperationException: remove>
Expected :Bills: [Bill{id=1, number=1000}]
Actual   :java.lang.UnsupportedOperationException: remove
<Click to see difference>


    at org.springframework.test.util.AssertionErrors.fail(AssertionErrors.java:59)
    at org.springframework.test.util.AssertionErrors.assertEquals(AssertionErrors.java:122)
    at org.springframework.test.web.servlet.result.ContentResultMatchers.lambda$string$4(ContentResultMatchers.java:136)
    at org.springframework.test.web.servlet.MockMvc$1.andExpect(MockMvc.java:196)
    at com.example.demo.controllers.BillControllerTest2.withdrawOneThousand(BillControllerTest2.java:51)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:210)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

Answer 1

您在模拟中返回的List.of(b1)返回不可修改的列表。 顺便说一句Arrays.asList也不支持删除。 如果您需要从集合中删除，您应该将模拟的返回更改为类似

new ArrayList<>(List.of(b1));
new ArrayList<>(Arrays.asList(b2));

所以完整的代码应该是这样的：

when(mockRepo.findByValue(1000)).thenReturn(new ArrayList<>(List.of(b1)));
when(mockRepo.findByValue(500)).thenReturn(new ArrayList<>(Arrays.asList(b2)));
when(mockRepo.findByValue(100)).thenReturn(new ArrayList<>(Arrays.asList(b3)));
when(mockRepo.findAll()).thenReturn(new ArrayList<>(Arrays.asList(b1, b2, b3)));