Apache Camel 多部分路由

Question

我正在尝试通过 Apache Camel 将文件路由到 HTTP 文件上传 API。但是我遇到了以下异常

org.apache.camel.InvalidPayloadException: No body available of type: java.io.InputStream but has value: org.apache.http.entity.mime.MultipartFormEntity@71ef4d4f of type: org.apache.http.entity.mime.MultipartFormEntity on: org.apache.camel.component.file.GenericFileMessage@7e693963. Caused by: No type converter available to convert from type: org.apache.http.entity.mime.MultipartFormEntity to the required type: java.io.InputStream with value org.apache.http.entity.mime.MultipartFormEntity@71ef4d4f. Exchange[org.apache.camel.component.file.GenericFileMessage@7e693963]. Caused by: [org.apache.camel.NoTypeConversionAvailableException - No type converter available to convert from type: org.apache.http.entity.mime.MultipartFormEntity to the required type: java.io.InputStream with value org.apache.http.entity.mime.MultipartFormEntity@71ef4d4f]

有人可以帮忙吗？ 以下是我到目前为止尝试过的

与 URL api/fileupload 映射的文件上传控制器方法需要 MultipartHttpServletRequest

MyCamelRouter.java

public class MyCamelRouter extends RouteBuilder {

@Override
public void configure() throws Exception {
    from("file:C:/src")
        .process(new MyProcessor())
        .log("POST ${header.CamelFileName} to /upload")
        .setHeader(Exchange.CONTENT_TYPE, constant("multipart/form-data"))
        .setHeader(Exchange.HTTP_METHOD, constant("POST"))
        .to("http:localhost:8080/sampleUploader/api/fileupload")
        .log("HTTP response status: ${header.CamelHttpResponseCode}")
        .log(LoggingLevel.DEBUG, "HTTP response body:\n${body}");
}

}

在 MyProcessor.java 中

public class MyProcessor implements Processor {
    public void process(Exchange exchange) throws Exception {

        File filetoUpload = exchange.getIn().getBody(File.class);
        String fileName = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);

        MultipartEntityBuilder entity = MultipartEntityBuilder.create();
        entity.addTextBody("fileName", fileName);
        entity.addBinaryBody("file", new File(filePath));

        exchange.getOut().setBody(entity.build());  
    }

}

This 是我为此关注的链接（Scala DSL）

Answer 1

当它说你需要一个 InputStream 时，消息很清楚

方法 build 返回一个 HttpEntity。

http://hc.apache.org/httpcomponents-client-ga/httpmime/apidocs/org/apache/http/entity/mime/MultipartEntityBuilder.html

你可以试试getContent()方法

http://hc.apache.org/httpcomponents-core-ga/httpcore/apidocs/org/apache/http/HttpEntity.html?is-external=true

尝试改变你的：

exchange.getOut().setBody(entity.build());  

到：

exchange.getOut().setBody(entity.build().getContent());  

更新

在您发表评论后，您可以做的另一件事是：

ByteArrayOutputStream out = new ByteArrayOutputStream();
entity.build().writeTo(out);
InputStream  inputStream = new ByteArrayInputStream(out.toByteArray());
exchange.getOut().setBody(inputStream);