com.fasterxml.jackson.core.JsonGenerationException: Can not write a field name, expecting a value

Caused by: com.fasterxml.jackson.core.JsonGenerationException: Can not write a field name, expecting a value
	at com.fasterxml.jackson.core.JsonGenerator._reportError(JsonGenerator.java:1961)
	at com.fasterxml.jackson.core.json.UTF8JsonGenerator.writeFieldName(UTF8JsonGenerator.java:238)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:725)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:119)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:79)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:18)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
	at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1396)
	at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:913)
	at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:287)
	... 65 common frames omitted

此异常是bean 字段序列化异常。因为我的实体添加了序列化的注解

import com.fasterxml.jackson.databind.annotation.JsonSerialize;

public class BindBankCardVO {
    /**
     * 自增主键
     */
    @ApiModelProperty("自增主键")
    private Integer id;

    /**
     * 卡号
     */
    @ApiModelProperty("卡号")
    @JsonSerialize(using = AcctNoSerialize.class)
    private String acctNo;

    /**
     * 开户行
     */
    @ApiModelProperty("开户行")
    private String bankName;

}

AcctNoSerialize  这个类判断的时候没写 不满足条件是  也给写出去，等于一个字段就没有写出去。
 

以前的代码
 

package com.gaia.pay.vo;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;


public class AcctNoSerialize extends JsonSerializer {

    @Override
    public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        if (value != null&&value.length()>=16) {
            gen.writeString(new StringBuilder(value).replace(4, value.length() - 4, "********").toString());
        }

    }
}

修改后的代码
 

package com.gaia.pay.vo;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;

public class AcctNoSerialize extends JsonSerializer {

    @Override
    public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        if (value != null&&value.length()>=16) {
            gen.writeString(new StringBuilder(value).replace(4, value.length() - 4, "********").toString());
        } else {
            gen.writeString(value);
        }

    }
}