从 rest 模板获取打开的输入流以进行大文件处理

Question

我正在寻找一种从 rest 模板中获取打开的输入流的方法 - 我试图使用 ResponseExtractor，但是在返回之前流正在关闭，如下所示：

https://jira.spring.io/browse/SPR-7357

"Note that you cannot simply return the InputStream from the extractor, because by the time the execute method returns, the underlying connection and stream are already closed"

我希望有办法，我将不必直接在其余模板中写入我的输出流。

Answer 1

我没找到办法，流总是关闭。作为解决方法，我创建了以下代码：

public interface ResourceReader {
    void read(InputStream content);
}

实施如下：

public class StreamResourceReader implements ResourceReader {

private HttpServletResponse response;

public StreamResourceReader(HttpServletResponse response) {
    this.response = response;
}

@Override
public void read(InputStream content) {
    try {
        IOUtils.copy(content, response.getOutputStream());
    } catch (IOException e) {
        throw new IllegalStateException(e);
    }
}
}

然后在控制器中：

@RequestMapping(value = "document/{objectId}")
public void getDocumentContent(@PathVariable String objectId, HttpServletResponse response) {
    ResourceReader reader = new StreamResourceReader(response);
    service.readDocumentContent(objectId, reader);
}

调用休息模板：

restTemplate.execute(uri, HttpMethod.GET, null,
            new StreamResponseExtractor(reader));

和字符串响应提取器：

@Override
public ResponseEntity extractData(ClientHttpResponse response) throws IOException {
    reader.read(response.getBody());
    return null;
}

它就像一个魅力！ :)

从 rest 模板获取打开的输入流以进行大文件处理

Get opened input stream from rest template for large file processing

java

rest

spring

spring-mvc

resttemplate