java - 单元测试 Junit NullPointerException 和 NoSuchElement 有帮助!休息终点

Question

当我访问类来测试方法时，每次尝试定义新对象并使用新定义的对象时都会遇到异常。

测试错误:

  UserInformationControllerTest.deleteUser:83 » NullPointer
  UserInformationControllerTest.getUserInfo:27 » NullPointer
  UserInformationControllerTest.updateUserInfo:68 » NullPointer
  UserOrderControllerTest.createUserOrder:60 » NoSuchElement
  UserOrderControllerTest.getUserOrder:47 » NullPointer
  UserOrderControllerTest.updateUserOrder:85 » NullPointer

我的任务是为每个类(class)制作 4 个满意的案例和 4 个不满意的案例

我完全困惑了。

我的 UserInformation 测试类

private HashMap<Integer,UserInformation> userInformationHashMap;

@Test
public void getUserInfo(){
    UserInformationController userInformationController = new UserInformationController();
    this.userInformationHashMap = new HashMap<>();

    int user0 = 0;
    int user1 = 1;

    UserInformation userInformation0 = new UserInformation("Doug","Jones", "djones@gmail.com","17073");
    UserInformation userInformation1 = new UserInformation("Natalie","Peirce", "nataliepeirce12@yahoo.com","dynamicrabbit");

    this.userInformationHashMap.put(user0,userInformation0);
    this.userInformationHashMap.put(user1,userInformation1);

    userInformationController.getUserInfo(user0);
    userInformationController.getUserInfo(user1);

    Assert.assertEquals(userInformationController.getUserInfo(user0),userInformationController.getUserInfo(user1)); //False

    Assert.assertNotEquals(user0,user1); //True

}

@Test
public void createUser(){
    UserInformationController userInformationController = new UserInformationController();
    this.userInformationHashMap = new HashMap<>();

    UserInformation userInformation0 = new UserInformation("Troy","Green","tjg217@verizon.com","2012hummingbirds");
    UserInformation userInformation1 = new UserInformation("Sierra", "West","themostimportantwest@msn.com","shadeyglasses77");

    int user0 = userInformationController.createUser(userInformation0);//Can you tell me why this does not work
    int user1 = userInformationController.createUser(userInformation1);//Can you tell me why this does not work

    this.userInformationHashMap.put(user0, userInformation0);
    this.userInformationHashMap.put(user1, userInformation1);

    Assert.assertNotEquals(this.userInformationHashMap.get(user0),this.userInformationHashMap.get(user1)); //True

    Assert.assertNotNull(this.userInformationHashMap.get(user0)); //False
}

@Test
public void updateUserInfo(){
    UserInformationController userInformationController = new UserInformationController();
    this.userInformationHashMap = new HashMap<>();

    int userId = 0;
    UserInformation userInformation = new UserInformation("Nicole", "Rigby", "sexygirl69@babellon.com","throwmethemoney");
    UserInformation newUserInformation = new UserInformation("Kitty", "Morgan", "ilovecats@cats.com","cats");

    this.userInformationHashMap.put(userId,userInformation);

    Assert.assertEquals(this.userInformationHashMap.get(userId),userInformation); //True

    userInformationController.updateUserInfo(userId,newUserInformation); //Can you tell me why this does not work

    Assert.assertNotEquals(this.userInformationHashMap.get(userId),newUserInformation); //False
}

@Test
public void deleteUser(){
    UserInformationController userInformationController = new UserInformationController();
    this.userInformationHashMap = new HashMap<>();

    int user = 0;
    UserInformation userInformation = new UserInformation("Camryn","Resele","smartcookie@email.com","28564088");

    this.userInformationHashMap.put(user,userInformation);

    userInformationController.deleteUser(user);

    Assert.assertNull(this.userInformationHashMap.get(user));   //True
    Assert.assertTrue(this.userInformationHashMap.containsKey(user)); //False
}

}

用户信息 Controller

private HashMap<Integer,UserInformation> userInformationHashMap;


/**
 * Default json constructor`enter code here`
 * @return new user object
 */
@GetMapping(path = "/defaultUserInformation")
public UserInformation test()
{
    return new UserInformation("fname", "lname", "email", "pass");
}
/**
 * Gets the users information
 * @return users information
 */
@GetMapping (path = "/userInfo")
public UserInformation getUserInfo(@RequestParam ("id") int id){
    return userInformationHashMap.get(id);
}

/**
 * Sets the users information
 * @param userInformation userInformation model
 * @return users key
 */
@PostMapping (path = "/createUser")
public int createUser(@RequestBody UserInformation userInformation){

    if(this.userInformationHashMap == null){
        this.userInformationHashMap = new HashMap<>();
    }

    int maxKey = 0;

    if(this.userInformationHashMap.size() != 0){
        maxKey = Collections.max(this.userInformationHashMap.keySet()) + 1;
    }

    this.userInformationHashMap.put(maxKey,userInformation);

    return maxKey;
}

@PutMapping (path = "/updateUserInfo")
public void updateUserInfo(@RequestParam ("id") int id, @RequestBody UserInformation userInformation) {
    if (this.userInformationHashMap.containsKey(id)) {
        this.userInformationHashMap.put(id, userInformation);
    }
}

@DeleteMapping (path = "/deleteUser")
public void deleteUser(@RequestParam ("id") int id){
    this.userInformationHashMap.remove(id);
}

}

Answer 1

UserInformationController 中的

userInformationHashMap 从未初始化，这就是您收到 NullPointerException 的原因。

您正在 createUser 端点中初始化 HashMap，但在测试中从未调用它。

createUser 端点我看不出它在哪里失败，但无论如何，这段代码确实应该重新组织，因为它有很多失败点。 HashMap确实应该在创建 Bean 时初始化，并且您应该重新审视计算 Key 的方式。

此外，出于 Controller 测试目的，您应该使用 MockMvc而不是直接调用 Controller 方法。