SpringBoot 自定义JsonSerializer使用Bean

不知道为什么不可行---->不知道为什么可行

如果有知道原因的大神希望可以赐教

弄了好几个小时, 脑子好乱, 就不作总结了

demo如下:

package com.xceam.common.serializer;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.xceam.common.system.api.ISysBaseAPI;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.io.IOException;

/**
 * 用于用户id自动翻译为用户名
 *
 * @author xuyingfa
 * @date 2020/10/20 16:30
 */
@Slf4j
@Component
@NoArgsConstructor
public class UsernameSerializer extends JsonSerializer {

    private static ISysBaseAPI api;

    @Autowired
    public UsernameSerializer(ISysBaseAPI api) {
        UsernameSerializer.api = api;
    }

    @Override
    public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        try {
            String username = api.getUsernameById(value);
            gen.writeString(username);
        } catch (Exception e) {
            gen.writeString("-");
        }
    }
}