杰克逊动态过滤反序列化过程中的属性 [英] Jackson Dynamic filtering of properties during deserialization
问题描述
我有一个REST WS来更新一个接收JSON字符串作为输入的bean对象。
I have a REST WS to update a bean object which receives a JSON string as input.
ABean entity = svc.findEntity(...);
objectMapper.readerForUpdating(entity).readValue(json);
[...]
svc.save(entity);
ABean是一个包含其他对象的复杂类型,例如:
class ABean {
public BBean b;
public CBean c;
public String d;
}
svc.save(...)将保存bean和嵌入式对象。
svc.save(...) will save the bean and the embedded objects.
出于安全考虑,我想过滤掉一些可以通过JSON字符串更新的属性,但我想这样做动态地,以便对于每个WS(或用户角色),我可以决定阻止更新哪些属性(所以我不能简单地使用Jackson视图)
For security reasons I want to filter out some of the properties that can be updated by the JSON string, but I want to do this dynamically, so that for every WS (or user Role) I can decide which properties to prevent to be updated (so I can't simply use the Jackson Views)
To总结一下,有什么方法可以在JSON反序列化期间动态过滤掉属性吗?
To summarize, is there any way I can dynamically filter out properties during JSON Deserialization?
推荐答案
另一种方法是使用BeanDeserializerModifier:
Another way is using BeanDeserializerModifier:
private static class BeanDeserializerModifierForIgnorables extends BeanDeserializerModifier {
private java.lang.Class<?> type;
private List<String> ignorables;
public BeanDeserializerModifierForIgnorables(java.lang.Class clazz, String... properties) {
ignorables = new ArrayList<>();
for(String property : properties) {
ignorables.add(property);
}
this.type = clazz;
}
@Override
public BeanDeserializerBuilder updateBuilder(
DeserializationConfig config, BeanDescription beanDesc,
BeanDeserializerBuilder builder) {
if(!type.equals(beanDesc.getBeanClass())) {
return builder;
}
for(String ignorable : ignorables) {
builder.addIgnorable(ignorable);
}
return builder;
}
@Override
public List<BeanPropertyDefinition> updateProperties(
DeserializationConfig config, BeanDescription beanDesc,
List<BeanPropertyDefinition> propDefs) {
if(!type.equals(beanDesc.getBeanClass())) {
return propDefs;
}
List<BeanPropertyDefinition> newPropDefs = new ArrayList<>();
for(BeanPropertyDefinition propDef : propDefs) {
if(!ignorables.contains(propDef.getName())) {
newPropDefs.add(propDef);
}
}
return newPropDefs;
}
}
您可以将修改器注册到ObjectMapper: / p>
You can register the modfier to the ObjectMapper with:
BeanDeserializerModifier modifier = new BeanDeserializerModifierForIgnorables(YourType.class, "name");
DeserializerFactory dFactory = BeanDeserializerFactory.instance.withDeserializerModifier(modifier);
ObjectMapper mapper = new ObjectMapper(null, null, new DefaultDeserializationContext.Impl(dFactory));
然后忽略定义的属性。如果使用@JsonAnySetter注释,则可以忽略updateBuilder方法。
Then the defined properties are ignored. You can ignore the updateBuilder method if you use the @JsonAnySetter annotation.
问候,
Martin
Greetings, Martin
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