Question

我试图在play1.2.4中移植到YABE来播放2.0.4 Java。为此，我创建了一个initial-data.yml并尝试使用Global.java加载它

#Users
users:
    - !!models.User
        email:      bob@gmail.com
        password:   secret
        fullname:   Bob
        isAdmin:    true
#Posts

posts:

    - !!models.Post
        id:         1
        title:      About the model layer
        postedAt:   2009-06-14
        author:     
            - !!models.User
                email: bob@gmail.com
        content:    >
                    The model has a central position in a Play! application. Cut....

My Global.java位于

之下

public void onStart(Application app) {
        InitialData.insert(app);
    }

    static class InitialData {
        public static void insert(Application app) {
            if(Ebean.find(User.class).findRowCount() == 0) {
                Map<String, List<Object>> all = (Map<String, List<Object>>)Yaml.load("initial-data.yml");
                Ebean.save(all.get("users"));
                Ebean.save(all.get("posts"));
                Ebean.save(all.get("comments"));
            }
        }
    }

加载时我遇到以下错误

ConstructorException：null;无法为标记构造java对象：yaml.org，2002：models.Post; exception =无法为JavaBean = model.Post@1创建property = author;没有为类模型找到3个参数的合适构造函数。用户

org.yaml.snakeyaml.constructor.ConstructorException: null; Can't construct a java object for tag:yaml.org,2002:models.Post; exception=Cannot create property=author for JavaBean=models.Post@1; No suitable constructor with 3 arguments found for class models.User

     org.yaml.snakeyaml.constructor.Constructor$ConstructYamlObject.construct(Constructor.java:333)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:183)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructSequenceStep2(BaseConstructor.java:277)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructSequence(BaseConstructor.java:248)

     org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlSeq.construct(SafeConstructor.java:440)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:183)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:326)

     org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:143)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:307)

     org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:459)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:183)

     org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:142)

     org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:128)

     org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:480)

     org.yaml.snakeyaml.Yaml.load(Yaml.java:411)

任何想法为什么会这样？

Answer 1

我与YAML合作已经有一段时间了，但看起来好像你是在帖子中重新创建一个新用户，而不是引用Bob。

我会尝试这样的事情：

models.User(bob):
  email:      bob@gmail.com
  password:   secret
  fullname:   Bob
  isAdmin:    true

models.Post(firstPost):
  id:         1
  title:      About the model layer
  postedAt:   2009-06-14
  author:     bob
  content:    The model has a central position in a Play! application.

Answer 2

曼努埃尔，谢谢你的帮助。

当我稍微修改YAML时，我得到它的工作，我只是删除了“ - ”，它位于“model.class”前面

#Users
users:
    - !!models.User
        email:      bob@gmail.com
        password:   secret
        fullname:   Bob
        isAdmin:    true
#Posts

posts:

    - !!models.Post
        id:         1
        title:      About the model layer
        postedAt:   2009-06-14
        author: !!models.User
                email: bob@gmail.com
        content:    >
                    The model has a central position in a Play! application. Cut....

知道“ - ”代表什么？

在play 2.0中加载initial-data.yml时出现问题

2 个答案: