JSON 路径“$.name”处没有值，异常：json 不能为 null 或为空，使用 Mockmvc 和 Spring-boot

Question

本着学习 Spring-boot with Spring Mock-Mvc and/or Mockito 的精神，我构建了一个小的 API ，以后可能会变得复杂当我学到更多东西时。

主题是 "A Song of Ice and Fire" 或 "Game Of Thrones"。到目前为止，我只有一个包，当您向“/Westeros”发送请求时，您可以在其中添加、删除和获取不同的王国。每个王国现在只需要一个名字属性。

我使用的数据库是Neo4J。

我把代码上传到github，这里是linkhttps://github.com/darwin757/IceAndFire

问题：问题出在我的 KingdomControllerTest class 方法 addKingdomTest 和 updateKingdomTest

    @Test
public void addKingdomTest() throws Exception {

    mockMvc.perform(post("/Westeros").contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"name\":\"Dorne\"}")
            .accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isCreated()).andReturn();

    //This part of the test is not working
    mockMvc.perform(get("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
            .andExpect(jsonPath("$.name").value("Dorne"));

}

@Test
public void updateKingdomTest() throws Exception {

    mockMvc.perform(post("/Westeros").contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"name\":\"Dorne\"}")
            .accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isCreated());

    mockMvc.perform(put("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)
            .content("{\"name\":\"theReach\"}").accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk());

    //This Part of the test is not working
    mockMvc.perform(get("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
            .andExpect(jsonPath("$.name").value("the Reach"));

}

如你所见，当我要求 API 创建一个新王国时，它 returns 201 isCreated 或 200 isOK，但是当我发送一个 get 请求时，我得到一个 "No value at JSON path exception"

java.lang.AssertionError: No value at JSON path "$.name", exception: json can not be null or empty
at org.springframework.test.util.JsonPathExpectationsHelper.evaluateJsonPath(JsonPathExpectationsHelper.java:245)
at org.springframework.test.util.JsonPathExpectationsHelper.assertValue(JsonPathExpectationsHelper.java:99)
at org.springframework.test.web.servlet.result.JsonPathResultMatchers.match(JsonPathResultMatchers.java:100)
at org.springframework.test.web.servlet.MockMvc.andExpect(MockMvc.java:171)
at com.example.Westeros.Kingdoms.KingdomControllerTest.addKingdomTest(KingdomControllerTest.java:95)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
at org.junit.runners.ParentRunner.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access[=14=]0(ParentRunner.java:58)
at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

总的来说，我对 Spring 很陌生，我没有在 spring Mock-Mvc 或 Mockito 上找到合适的指南。我不知道哪里出了问题，是我的语法还是我的 API？任何帮助将不胜感激。

这是完整的 Class:

package com.example.Westeros.Kingdoms;

import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.stubbing.OngoingStubbing;
import org.springframework.beans.factory.annotation.Autowired;
import 
org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import static org.mockito.Mockito.when;
import static org.junit.Assert.*;
import static org.mockito.Mockito.any;

import static 
org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static 
org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static 
org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static 
org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
import static 
org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static 
org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static 
org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
import static 
org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup;

import java.util.ArrayList;
import java.util.List;
import org.junit.Assert;

//TODO Major refactor required to clean up this class and consider the 
testing strategy 
@RunWith(SpringRunner.class)
@SpringBootTest
public class KingdomControllerTest {

@Autowired
private WebApplicationContext context;

private MockMvc mockMvc;

@MockBean
private KingdomService kingdomServiceMock;

@Before
public void setup() {
    this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context).build();
}

@Test
public void getAllKingdomsTest() throws Exception {

    List<Kingdom> kingdoms = setUpAListOfKingdoms();

    when(kingdomServiceMock.getAllKingdoms()).thenReturn(kingdoms);

    mockMvc.perform(get("/Westeros").accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
            .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))
            .andExpect(jsonPath("$[0].name").value("TheNorth"))
            .andExpect(jsonPath("$[1].name").value("TheRiverlands"));
}


@Test
public void getKingdomTest() throws Exception {

    Kingdom theNorth = setUpAKingdom("TheNorth");
    kingdomServiceMock.addKingdom(theNorth);

    when(kingdomServiceMock.getKingdom("TheNorth")).thenReturn(theNorth);

    mockMvc.perform(get("/Westeros/TheNorth")).andExpect(status().isOk())
            .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))
            .andExpect(jsonPath("$.name").value("TheNorth"));
}

// FIXME This test is returning 201 isCreated,
// but if I perform a get after I get an assertion exception that the variable
// name is empty.
@Test
public void addKingdomTest() throws Exception {

    mockMvc.perform(post("/Westeros").contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"name\":\"Dorne\"}")
            .accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isCreated()).andReturn();

    //This part of the test is not working
    mockMvc.perform(get("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
            .andExpect(jsonPath("$.name").value("Dorne"));

}

@Test
public void updateKingdomTest() throws Exception {

    mockMvc.perform(post("/Westeros").contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"name\":\"Dorne\"}")
            .accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isCreated());

    mockMvc.perform(put("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)
            .content("{\"name\":\"theReach\"}").accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk());

    //This Part of the test is not working
    mockMvc.perform(get("/Westeros/Dorne").contentType(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
            .andExpect(jsonPath("$.name").value("the Reach"));

}

@Test
public void deleteKingdomTest() throws Exception {

    mockMvc.perform(post("/Westeros").contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"name\":\"theVale\"}")
            .accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isCreated());

    mockMvc.perform(delete("Westeros/theVale").contentType(MediaType.APPLICATION_JSON_UTF8))
            .andExpect(status().isNotFound());

}

// FIXME refer to the KingdomController class, the method should be moved to
// another class more suited to it's purpose
@Test
public void deleteAlltest() {
}

private List<Kingdom> setUpAListOfKingdoms() {

    Kingdom theNorth = setUpAKingdom("TheNorth");
    Kingdom theRiverlands = setUpAKingdom("TheRiverlands");

    List<Kingdom> kingdoms = new ArrayList<Kingdom>();

    kingdoms.add(theNorth);
    kingdoms.add(theRiverlands);

    // FIXME wrong place for this code but I can't find another
    kingdomServiceMock.addKingdom(theNorth);
    kingdomServiceMock.addKingdom(theRiverlands);

    return kingdoms;

}

private Kingdom setUpAKingdom(String name) {

    Kingdom kingdom = new Kingdom(name);
    return kingdom;
}

}

提前谢谢你。

Answer 1

好的，我检查了你的 github，问题是你在嘲笑你的 KingdomService:

@MockBean
private KingdomService kingdomServiceMock;

但是在这些失败的测试中，您没有断言被调用的模拟方法有任何行为。模拟 class 的默认响应是 return null 因此这里的 kingdomService.getKingdom(name) 方法 returns null always:

@RequestMapping("/Westeros/{name}")
    public Kingdom getKingdom(@PathVariable String name) {
        return kingdomService.getKingdom(name);
}

你可能想做更多的集成测试，在这种情况下我会说你不想模拟服务。

因此，在您当前正在运行的 get 测试中，您应该自动装配存储库并实际添加您要测试的王国，而不是设置模拟行为，例如：

@Autowired
KingdomRepository kingdomRepository;

@Test
@Transactional
    public void getAllKingdomsTest() throws Exception {

        List<Kingdom> kingdoms = setUpAListOfKingdoms();

        kingdomRepository.saveAll(kingdoms);
        kingdomRepository.flush();

        mockMvc.perform(get("/Westeros").accept(MediaType.APPLICATION_JSON_UTF8)).andExpect(status().isOk())
                .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))
                .andExpect(jsonPath("$[0].name").value("TheNorth"))
                .andExpect(jsonPath("$[1].name").value("TheRiverlands"));
    }

@Transactional 注释确保您与数据库的交互在每次测试结束时回滚。

编辑：您还应该确保您的存储库实现的是 JpaRepository 而不是 PagingAndSortingRepository。通过这种方式，您可以在您的存储库上调用 .flush() 方法，以确保对数据库的所有未决更改立即刷新到它。

JSON 路径“$.name”处没有值，异常：json 不能为 null 或为空，使用 Mockmvc 和 Spring-boot

No value at JSON path "$.name", exception: json can not be null or empty, Using Mockmvc and Spring-boot

java

mockito

spring-boot

mockmvc