尝试使用自定义JsonSerializer（Jackson）时发生Stackoverflow异常

Question

我正在尝试使用Jackson将对象序列化到JSON，以便字段名基于一种类型的字段。

我有和这个线程中的OP一样的问题：

然而，这并不奏效。

我正在使用Wildfly 10.1 Final

null

CustomSerializer类：

public class CustomSerializer extends JsonSerializer<Object> {
  public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
    jgen.writeStartObject();
    jgen.writeObjectField(value.getClass().getSimpleName(), value);
    jgen.writeEndObject();
  }
}

>

将@jsonProperty（“data”）注释添加到object字段，因此我的Response类现在如下所示：

public class ResponseWithReturnValue extends Response {
    @JsonProperty("data")
    private Object object;

    public ResponseWithReturnValue (int code, String msg) {
        super(code, msg);
    }

    public Object getObject() {
        return object;
    }

    public void setObject(Object object) {
        this.object = object;
    }
}

当我测试它时，我得到了以下json对象：

{"code":0,"message":"Success","data":"test"}

现在，我尝试了本博客中的建议，并在我的ResponseWithReturnValue类上添加了@jsonSerialize(using=CustomSerializer.class)注释。

但是，现在我得到了这个StackOverflow：）异常：

Exception in thread "main" java.lang.StackOverflowError
at java.lang.Class.getEnclosingMethodInfo(Class.java:1072)
at java.lang.Class.getEnclosingClass(Class.java:1272)
at java.lang.Class.getSimpleBinaryName(Class.java:1443)
at java.lang.Class.getSimpleName(Class.java:1309)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)
at com.fasterxml.jackson.core.base.GeneratorBase.writeObject(GeneratorBase.java:324)
at com.fasterxml.jackson.core.JsonGenerator.writeObjectField(JsonGenerator.java:1415)
at rs.netset.authority.web.facade.utils.CustomSerializer.serialize(CustomSerializer.java:13)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2383)

我无法发布完整的stacktrace，因为它太长了。

有什么想法吗？

Answer 1

通过始终委托给相同的（自定义的）序列化程序，您已经创建了无限递归。行jgen.writeobjectfield(value.getClass().getSimplename()，value)；调用自定义序列化程序，以序列化object，后者再次调用jgen.writeobjectfield(...)等等。

您可以委托给另一个序列化程序或实际序列化对象：

jgen.writeObjectFieldStart("objectFieldName");
jgen.writeStringField("someValue", value.getSomeValue());
//...
jgen.writeEndObject();