Question

这没关系：

@RequestMapping(value = "/foos/{id}", method = RequestMethod.GET)
public ResponseEntity<Foo> _findOne(@PathVariable("id") Integer id) {
    Foo foo = findOne(id);
    if (foo == null) {
        return new ResponseEntity<Foo>(HttpStatus.NOT_FOUND);
    }
    return new ResponseEntity<Foo>(foo, HttpStatus.OK);
}

由于没有项目，尝试发生错误时异步版本失败）

服务器异常是：

java.lang.IllegalArgumentException: No converter found for return value of type: class org.springframework.http.ResponseEntity$DefaultBuilder
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:178) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:153) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:165) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]

这是DeferredResult版本

 @RequestMapping(value = "/foos/{id}", method = RequestMethod.GET)
public DeferredResult<ResponseEntity<Foo>> _findOne(@PathVariable("id") Integer id) {
    final DeferredResult<ResponseEntity<Foo>> deferred = new DeferredResult<>();
    findOne(id).singleOrDefault(null).timeout(1, TimeUnit.SECONDS)
            .subscribe(item -> {
                        if (item == null) {
                            deferred.setErrorResult(ResponseEntity.status(HttpStatus.NOT_FOUND));
                        } else {
                            deferred.setResult(ResponseEntity.ok(item));
                        }
                    }, t -> {
                        deferred.setErrorResult(ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR));
                    }
            );
    return deferred;
}

我已阅读Spring Boot Application: No converter found for return value of type但我认为我的情况有所不同，因为只有当我返回NOT_FOUND

时

Answer 1

使用this SO answer和this example 我看到deferred.setErrorResult 需要一个异常所以我现在有：

deferred.setErrorResult(new FooNotFoundException());

其中：

@ResponseStatus(HttpStatus.EXPECTATION_FAILED)
static class FooNotFoundException extends Exception {
}

保留此问题而不是将其删除为java.lang.IllegalArgumentException而不是链接的SO问题，并且非常令人困惑。

springmvc DeferredResult ..＆＃34;找不到类型返回值的转换器：class org.springframework.http.ResponseEntity $ DefaultBuilder＆＃34;

1 个答案: