Question

我目前正在使用Spring WebFlux。我正在尝试使用Spring WebFlux上传大文件（70mo）。

我的控制器

@RequestMapping(method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public Flux<String> uploadHandler(@RequestBody Flux<Part> fluxParts, @RequestParam(value = "categoryType") String categoryType, @PathVariable(value = "traceabilityReportUuid") String traceabilityUuid) {
    return documentHandler.upload(fluxParts, UUID.fromString(traceabilityUuid), categoryType);
}

我的服务

public Flux<String> upload(Flux<Part> fluxParts, UUID traceabilityUuid, String categoryType) {

    return fluxParts
            .filter(part -> part instanceof FilePart)
            .ofType(FilePart.class)
            .flatMap(p -> this.upload(p, traceabilityUuid, categoryType));


}


private Mono<String> upload(FilePart filePart, UUID traceabilityUuid, String categoryType) {

    return filePart.content().collect(InputStreamCollector::new, (t, dataBuffer) -> t.collectInputStream(dataBuffer.asInputStream()))
            .flatMap(inputStreamCollector -> {
                upload(traceabilityUuid, inputStreamCollector.getInputStream(), filePart.filename(), categoryType);

                return Mono.just("OK");
            });
}

我的收藏家

public class InputStreamCollector {

private InputStream is;

public void collectInputStream(InputStream is) {
    if (this.is == null) this.is = is;
    this.is = new SequenceInputStream(this.is, is);
}

public InputStream getInputStream() {
    return this.is;
}

}

最后，我通过这种方式检索完整的输入流：inputStreamCollector.getInputStream（）并传递给我的对象。

我用这个对象来发送到存储桶S3。

但是在发送到S3之前，我必须将其转换为文件（使用apache工具），我有一个stackoverflow异常。

java.lang.StackOverflowError: null
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)
at java.base/java.io.SequenceInputStream.read(SequenceInputStream.java:156)

它可以很好地处理一个小文件（7mo ..）

您有解决我问题的想法吗？

谢谢

Answer 1

最后我找到了解决方案！

https://github.com/entzik/reactive-spring-boot-examples/blob/master/src/main/java/com/thekirschners/springbootsamples/reactiveupload/ReactiveUploadResource.java

我修改了代码以返回InputStream，并且对大型文件也可以正常工作;-）

Answer 2

要将 DataBuffer 转换为 String 或 List ，您可以使用 Apache IOUtils 。在此示例中，我返回了助焊剂，为避免尝试/捕获，我用Mono.fromCallable包装。

protected Flux<String> getLines(final DataBuffer dataBuffer) {
    return Mono.fromCallable(() -> IOUtils.readLines(dataBuffer.asInputStream(), Charsets.UTF_8))
        .flatMapMany(Flux::fromIterable);
}

Answer 3

此示例将帮助您了解如何从FilePart加载数据：

public static Mono<String> readBase64Content(FilePart filePart) {
    return filePart.content().flatMap(dataBuffer -> {
         byte[] bytes = new byte[dataBuffer.readableByteCount()];
         dataBuffer.read(bytes);
         String content = Base64.getEncoder().encodeToString(bytes);
         return Mono.just(content);
    }).last();
}

休息方法

@PostMapping(value = "/person/{personId}/photo", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
Mono<String> uploadPhoto(@PathVariable Long personId, @RequestPart("photo") Mono<FilePart> photo) {
        return photo.ofType(FilePart.class).flatMap(StringUtil::readBase64Content);
}

Spring Webflux Flux <databuffer>转换为InputStream

3 个答案: