当杰克逊反序列化失败时，Jersey异常映射器无法正常工作 [英] Jersey Exception mappers not working when jackson deserialization fails

问题描述

我在REST API中使用Jersey 2.10和Jackson序列化/反序列化功能。

I am using Jersey 2.10 with Jackson serialization/deserialization feature in my REST API.

我的想法是让我的REST API始终返回标准的JSON错误响应。为此，我有ExceptionMapper类，为Jersey应用程序中抛出的任何异常构建正确的json错误响应。我还有一个生成相同类型的JSON响应的jsp，我在web.xml中注册为error-page，它涵盖了Jersey加载之前可能出现的所有错误。

My idea is to make my REST API to always return a standard JSON error response. For that I have ExceptionMapper classes that build proper json error responses for any exception being thrown in the Jersey application. I also have a jsp which produces the same kind of JSON response, which I registered as error-page in the web.xml that covers all the errors that could come before Jersey being loaded.

但是有一种情况，我的Exception mappers和我的json生成jsp都没有工作，也就是将一个错误形成的json发送到POST REST端点，它只返回以下消息：

But there is one case in which neither my Exception mappers nor my json producing jsp are working, that is when sending a bad formed json to a POST REST endpoint which just returns the following message:

HTTP/1.1 400 Bad Request
Server: Apache-Coyote/1.1
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, DELETE, PUT
Content-Type: text/plain
Content-Length: 210
Date: Tue, 24 Jun 2014 22:14:11 GMT
Connection: close

Can not deserialize instance of com.example.rest.User[] out of START_OBJECT token
 at [Source: org.glassfish.jersey.message.internal.EntityInputStream@1dcccac; line: 1, column: 1]

如何让Jersey返回我的自定义错误响应而不是这个？

How can I make Jersey to return my custom error response instead of this?

更新：

根据@Lucasz的回答，我做了更多的研究，发现在com.fasterxml.jackson.jaxrs.base包中定义了两个异常映射器（ https://github.com/FasterXML/jackson-jaxrs-providers/tree/master/base/src/main/ java / com / fasterxml / jackson / jaxrs / base ）JsonMappingExceptionMapper和JsonParseExceptionMapper似乎是在影响我的自定义映射器。

Based on the answer by @Lucasz, I did more research and found that there are two Exception mappers defined inside the package com.fasterxml.jackson.jaxrs.base (https://github.com/FasterXML/jackson-jaxrs-providers/tree/master/base/src/main/java/com/fasterxml/jackson/jaxrs/base) JsonMappingExceptionMapper and JsonParseExceptionMapper that seem to be shadowing my custom mappers.

如何取消注册这些映射器？

How can I unregister those mappers?

这就是我目前正在注册地图制作者的方式：

This is how I am currently registering the mappers:

@ApplicationPath("/")
public class MyApp extends ResourceConfig{
    public SyntheticAPIApp() {
        packages("com.example.resource", "com.example.mapper");
        register(org.glassfish.jersey.jackson.JacksonFeature.class);
    }
}

推荐答案

我使用如下的异常映射器测试它：

I tested it with an exception mapper like below:

import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

import com.fasterxml.jackson.core.JsonProcessingException;

@Provider
public class JsonProcessingExceptionMapper implements ExceptionMapper<JsonProcessingException>{

        public static class Error {
            public String key;
            public String message;
        }

        @Override
        public Response toResponse(JsonProcessingException exception) {
            Error error = new Error();
            error.key = "bad-json";
            error.message = exception.getMessage();
            return Response.status(Status.BAD_REQUEST).entity(error).build();
        }
}

并且有效。

更新：将JsonParseException更改为JsonProcessingException（更一般）

Update: changed JsonParseException to JsonProcessingException (more general)

Update2：
为了避免注册不需要的映射器，请替换

Update2: In order to avoid registering the unwanted mappers replace

register(org.glassfish.jersey.jackson.JacksonFeature.class);

with

register(com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider.class);

查看 JacksonFeature ，你会明白发生了什么。

Look at the source code of JacksonFeature and you'll understand what's happening.

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