在Jackson中动态地向任何对象的所有属性名追加文本

Question

@Value
public class Example {
    @JsonProperty("StrValue")
    String strValue;
    @JsonProperty("Internal")
    Internal internal;
    
    @Value
    public static class Internal {
        @JsonProperty("InternalValue")
        String internalValue;
    }
}

"Example" : {
  "StrValue": "v1",
  "Internal": {
    "InternalValue": "v2"
  }
}

"ExampleFirst" : {
  "StrValueFirst": "v1",
  "InternalFirst": {
    "InternalValueFirst": "v2"
  }
}

(second)

请注意，这应该适用于嵌套属性和任何类的任何对象。有没有一个简单的方法可以做到这一点？我觉得这可能是BeanSerializerModifier或其他一些自定义序列化机制的工作，但是，自定义序列化API非常低级，文档很少。

Answer 1

回答我自己的问题，因为我（有点）解决了它：

首先，我将创建BeanPropertyWriter的子类，例如

   class AppendingPropertyWriter extends BeanPropertyWriter {
        private final BeanPropertyWriter writer;

        public AppendingPropertyWriter(BeanPropertyWriter writer) {
            super(writer);
            this.writer = writer;
        }

        @Override
        public void serializeAsField(Object bean,
                                     JsonGenerator gen,
                                     SerializerProvider prov) throws Exception {
            Object value = writer.get(bean);
            gen.writeObjectField(writer.getName() + "First", value);
        }
    }

然后将其添加到BeanSerializerModifier，如下所示：

public class AppendingSerializerModifier extends BeanSerializerModifier {

    @Override
    public List<BeanPropertyWriter> changeProperties(SerializationConfig config, BeanDescription beanDesc, List<BeanPropertyWriter> beanProperties) {
        for (int i = 0; i < beanProperties.size(); i++) {
            BeanPropertyWriter writer = beanProperties.get(i);
            beanProperties.set(i, new AppendingPropertyWriter(writer));
        }
        return beanProperties;
    }
}

        var serializerModifier = new AppendingSerializerModifier();
        var sf = BeanSerializerFactory.instance.withSerializerModifier(serializerModifier);

        ObjectMapper mapper = new XmlMapper();
        mapper.setSerializerFactory(sf);