如何使用Jackson将映射序列化为列表

How can I serialize a property which is a Map as a List of the Map's values? I've been able to do other simple conversions using the @JsonSerialize(using=...) annotation on the getter. However, I am not sure if one exists for what I want to do.

如何将映射的属性序列化为映射值的列表?我可以使用getter上的@JsonSerialize(使用=…)注释进行其他简单的转换。然而，我不确定是否存在一个我想做的事情。

2 个解决方案

#1

We needed something similar, in our case we used a customized @JsonSerialize as you commented, and it was stupid simple:

我们需要类似的东西，在我们的例子中，我们使用了定制的@JsonSerialize，就像你评论的那样，它是愚蠢的简单:

public class MyCustomSerializer extends JsonSerializer<Map<?, ?>> {
    @Override
    public void serialize(final Map<?, ?> value, final JsonGenerator jgen, final SerializerProvider provider)
            throws IOException, JsonProcessingException {
        jgen.writeObject(value.values());
    }
}

Code using it:

代码使用它:

import java.io.IOException;
import java.util.Collections;
import java.util.Map;

import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializerProvider;
import org.codehaus.jackson.map.annotate.JsonSerialize;

public class JacksonTest {

    public static class ModelClass {
        private final Map<String, String> map;

        public ModelClass(final Map<String, String> map) {
            super();
            this.map = map;
        }

        @JsonSerialize(using = MyCustomSerializer.class)
        public Map<String, String> getMap() {
            return map;
        }

    }

    public static void main(final String[] args) throws JsonGenerationException, JsonMappingException, IOException {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.writeValue(System.out, new ModelClass(Collections.singletonMap("test", "test")));
    }

}

#2

I implemented using default Serializer to handle values that are not just String :

我实现了使用默认序列化器来处理不只是字符串的值:

@Override
public void serialize(final Map<Long, ?> value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException,
            JsonProcessingException {
   provider.defaultSerializeValue(value.values(), jgen);
}

EDIT : As mentioned by Radu Simionescu this solution only works for Maps of Pojos.

编辑:正如Radu Simionescu提到的，这个解决方案只适用于pojo地图。

#1