Java Jackson @JsonProperty(required=true) 不会抛出异常
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Hymanson @JsonProperty(required=true) doesn't throw an exception
提问by jaksky
I am using Hymanson 2.2 annotation @JsonProperty with required set to true. While deserializing json file which doesn't contain that property via ObjectMapper readValue() method no exception is being thrown. Is it supposed to work in a different way or did I missed something?
我正在使用 Hymanson 2.2 注释 @JsonProperty，并将 required 设置为 true。通过 ObjectMapper readValue() 方法反序列化不包含该属性的 json 文件时，不会引发异常。它应该以不同的方式工作还是我错过了什么？
My dto class:
我的 dto 课：
public class User {
public enum Gender {MALE, FEMALE}
;
public static class Name {
private String _first, _last;
public String getFirst() {
return _first;
}
public String getLast() {
return _last;
}
public void setFirst(String s) {
_first = s;
}
public void setLast(String s) {
_last = s;
}
}
private Gender _gender;
private Name _name;
private boolean _isVerified;
private byte[] _userImage;
@JsonProperty(value ="NAAME",required = true)
public Name getName() {
return _name;
}
@JsonProperty("VERIFIED")
public boolean isVerified() {
return _isVerified;
}
@JsonProperty("GENDER")
public Gender getGender() {
return _gender;
}
@JsonProperty("IMG")
public byte[] getUserImage() {
return _userImage;
}
@JsonProperty(value ="NAAME",required = true)
public void setName(Name n) {
_name = n;
}
@JsonProperty("VERIFIED")
public void setVerified(boolean b) {
_isVerified = b;
}
@JsonProperty("GENDER")
public void setGender(Gender g) {
_gender = g;
}
@JsonProperty("IMG")
public void setUserImage(byte[] b) {
_userImage = b;
}
}
This is how do I deserialize the class:
这是我如何反序列化类：
public class Serializer {
private ObjectMapper mapper;
public Serializer() {
mapper = new ObjectMapper();
SimpleModule sm = new SimpleModule("PIF deserialization");
mapper.registerModule(sm);
}
public void writeUser(File filename, User user) throws IOException {
mapper.writeValue(filename, user);
}
public User readUser(File filename) throws IOException {
return mapper.readValue(filename, User.class);
}
}
This is how it is actually called:
这就是它的实际名称：
Serializer serializer = new Serializer();
User result = serializer.readUser(new File("user.json"));
Actuall json looks like:
实际的 json 看起来像：
{"GENDER":"FEMALE","VERIFIED":true,"IMG":"AQ8="}
I would expect that since _name is not specified in json file and is required that the exception will be thrown.
我希望因为 _name 没有在 json 文件中指定并且需要抛出异常。
采纳答案by StaxMan
As per Hymanson annotations javadocs: "Note that as of 2.0, this property is NOT used by BeanDeserializer: support is expected to be added for a later minor version."
根据 Hymanson 注释javadocs：“请注意，从 2.0 开始，BeanDeserializer 不使用此属性：预计会为以后的次要版本添加支持。”
That is: no validation is performed using this settings. It is only (currently) used for generating JSON Schema, or by custom code.
即：不使用此设置执行验证。它仅（当前）用于生成 JSON Schema，或用于自定义代码。
回答by Bojan Petkovic
With Hymanson 2.6 you can use required, however you have to do it using JsonCreator
使用 Hymanson 2.6，您可以使用 required，但是您必须使用 JsonCreator
For example:
例如：
public class MyClass {
@JsonCreator
public MyClass(@JsonProperty(value = "x", required = true) Integer x, @JsonProperty(value = "value_y", required = true) Integer y) {
this.x = x;
this.y = y;
}
private Integer x;
private Integer y;
}
If x or y are not present an exception will be thrown when trying to deserialize it.
如果 x 或 y 不存在，则在尝试反序列化时会抛出异常。
