Question

我有一个附件属性为LOB的实体。在通过Jackson JSON转换获取REST服务响应时，出现以下异常。我在Spring JPA中使用Spring Boot

@Lob
@Column(name = "attachment")
private byte[] attachment;

at com.fasterxml.jackson.module.afterburner.ser.ObjectMethodPropertyWriter.serializeAsField(ObjectMethodPropertyWriter.java:87)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:689)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
    at com.fasterxml.jackson.module.afterburner.ser.ObjectMethodPropertyWriter.serializeAsField(ObjectMethodPropertyWriter.java:87)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:689)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
    at com.fasterxml.jackson.module.afterburner.ser.ObjectMethodPropertyWriter.serializeAsField(ObjectMethodPropertyWriter.java:87)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:689)

2018-08-05 20:24:19.862  WARN 2084 --- [ XNIO-2 task-12] .m.m.a.ExceptionHandlerExceptionResolver : Failed to invoke @ExceptionHandler method: public default org.springframework.http.ResponseEntity org.zalando.problem.spring.web.advice.general.ThrowableAdviceTrait.handleThrowable(java.lang.Throwable,org.springframework.web.context.request.NativeWebRequest)

java.io.IOException: UT010029: Stream is closed
    at io.undertow.servlet.spec.ServletOutputStreamImpl.write(ServletOutputStreamImpl.java:136)
    at org.springframework.security.web.util.OnCommittedResponseWrapper$SaveContextServletOutputStream.write(OnCommittedResponseWrapper.java:639)
    at com.fasterxml.jackson.core.json.UTF8JsonGenerator._flushBuffer(UTF8JsonGenerator.java:2039)
    at com.fasterxml.jackson.core.json.UTF8JsonGenerator.flush(UTF8JsonGenerator.java:1051)
    at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:953)
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:286)
    at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:106)
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:231)
    at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:203)
    at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81)

Answer 1

您需要使用字节数组序列化：

字节数组序列化器：

public class ByteArraySerializer extends JsonSerializer<byte[]> {

 @Override
 public void serialize(byte[] bytes, JsonGenerator jgen,
        SerializerProvider provider) throws IOException,
        JsonProcessingException {
    jgen.writeStartArray();

    for (byte b : bytes) {
        jgen.writeNumber(unsignedToBytes(b));
    }

    jgen.writeEndArray();

}

private static int unsignedToBytes(byte b) {
    return b & 0xFF;
  }

}

使用序列化器：

@Lob
@Column(name = "attachment")
@JsonSerialize(using= ByteArraySerializer.class)
private byte[] attachment;

休息服务响应引发错误java.io.IOException：UT010029：流已关闭

1 个答案: