java - png 文件 上传 Restful Web 服务 java

Question

我尝试为我的网络服务编写一个图像文件上传 post 方法。这是我的发帖方法。图片文件可以通过post方法上传，但不能转换为Image类型。

@POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
@Produces("text/html")
public Response uploadFile(@FormDataParam("file") File file2) throws IOException {
    InputStream IS = null;

    String output = "";

    try {
        IS = new FileInputStream(file2);
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {

    }


    try {
        if (file2 != null && IS != null) {
            Image img = ImageIO.read(IS);
            if (img != null) {
                output = "image file transmission sucessed";

            } else {
                String out = convertStreamToString(IS);
                output = "file uploaded into post method, however can not transfer it into image type "+
                "\n"+ out;
            }

        } else if (file2 == null) {
            output = "the file uploaded into post method is null";
        }

    } catch (IOException e) {
        e.printStackTrace();

    }

    return Response.status(200).entity(output).build();

}

static String convertStreamToString(java.io.InputStream is) {
    java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
    return s.hasNext() ? s.next() : "";
}

“文件已上传到post方法中，但无法将其转为图像类型“+”\n”+ out；显示消息。我相信的原因是 inputStream 包含额外的文件信息+图像的内容。当我尝试将 inputStream 转换回 Image 时，我需要找到一种方法来摆脱传递的额外信息。

这是我的新版本:

@POST
@Path("/images")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response imageUpload(
        @FormDataParam("image") InputStream hereIsImage,
        @FormDataParam("image") FormDataContentDisposition hereIsName) {
    String path = "f://";
    if (hereIsName.getSize() == 0) {
        return Response.status(500).entity("image parameter is missing")
                .build();
    }
    String name = hereIsName.getFileName();
    path += name;

    try {
        OutputStream out = new FileOutputStream(new File(path));
        int read;
        byte[] bytes = new byte[1024];
        while ((read = hereIsImage.read(bytes)) != -1) {
            out.write(bytes, 0, read);
        }
        out.flush();
        out.close();
    } catch (IOException e) {
        return Response.status(500)
                .entity(name + " was not uploaded\n" + e.getMessage())
                .build();
    }
    return Response.status(200).entity(name + " was uploaded").build();
}

但是，当我上传图片时，会弹出错误:

[ERROR] An exception occurred during processing of the au.edu.rmit.srtwebservice.util.rest.testWS class. This class is ignored. com/sun/jersey/core/header/FormDataContentDisposition

testWS.calss 是我的方法所在的位置。

Answer 1

public Response uploadFile(@FormDataParam("file") File file2)

File 输入可能不起作用，因为您很可能从客户端发送八位字节流。因此，尝试使用 InputStream 作为输入类型，希望它能够工作。

public Response uploadFile(@FormDataParam("file") InputStream file2)