通过 MobileFirst Adapter 下载 PDF 文件

Question

我正在构建一个应用程序以从后端服务器下载 PDF 文件。我写了以下代码：

在后端服务器上，方法如下：

        @POST
        @Consumes(MediaType.APPLICATION_JSON)
        @Produces("application/pdf")
        public Response download() {
                ResponseBuilder response = Response.ok((Object) new File("myFile.pdf"));
                response.header("Content-Disposition", "attachment; filename=myFile.pdf");
                Response responseBuilder = response.build();
                return responseBuilder;

        }

我正在从我的适配器中调用此 rest 方法：

function downloadFile(){
            var input = {
                    method              : 'post',
                    returnedContentType : "plain",
                    path                : "getfiles",
                    body                : {
                        contentType : 'application/json;charset=utf-8',
                        content     : JSON.stringify({username: "testuser"})
                    }

            };
            var response = WL.Server.invokeHttp(input);
            return response;
}

通话结束后，我收到此服务的以下响应：

    {
       "errors": [
       ],
       "info": [
       ],
       "isSuccessful": true,
       "responseHeaders": {
          "Content-Disposition": "attachment; filename=myFile.pdf",
          "Content-Length": "692204",
          "Content-Type": "application\/pdf",
          "Date": "Thu, 15 Oct 2015 15:19:56 GMT",
          "X-Powered-By": "Servlet\/3.0"
       },
       "responseTime": 11,
       "statusCode": 200,
       "statusReason": "OK",
       "text":"%PDF-1.6\n%ï¿½ï¿½ï¿½ï¿½\n159 0 obj\n<<\/Linearized 1\/L 692204\/O 162\/E 156949\/N 25\/T 691602\/H [ 531 579]>>\nendobj\n"
--long lines of characters in text field.
    }

如何将此响应解析为 PDF 文件并将其显示给用户？当我右键单击适配器并选择运行作为 "call mobile adapter" 时，我也得到了这个响应，当我使用以下代码从应用程序中简单地调用这个适配器方法时：

    var invocationData = {
            adapter : "MyAdapter",
            procedure: "downloadFile",
            parameters: []
    };


    WL.Client.invokeProcedure(invocationData, {
        onSuccess: downloadFileOK, 
        onFailure: downloadFileFAIL,
        onConnectionFailure: disconnectDetect
    });

我在浏览器的控制台上得到了相同的响应，但是我的 "OnFailure" 方法 "downloadFileFAIL" 被调用了。

编辑以下是在浏览器控制台中打印的日志：

R\n>>\nstartxref\n451945\n%%EOF","errors":[],"isSuccessful":true,"statusReason":"OK","responseHeaders":{"Date":"Thu, 15 Oct 2015 21:52:40 GMT","Content-Length":"453132","Content-Disposition":"attachment; filename=myFile.pdf","Content-Type":"application\/pdf","X-Powered-By":"Servlet\/3.0"},"warnings":[],"responseTime":15,"totalTime":151,"info":[]}
worklight.js:5356 Procedure invocation error.WL.Logger.__log @ worklight.js:5356
worklight.js:5360 Uncaught Exception: Uncaught SyntaxError: Unexpected number at (compiled_code):3879WL.Logger.__log @ worklight.js:5360
worklight.js:3879 Uncaught SyntaxError: Unexpected number
worklight.js:5992 Local storage capacity reached. WL.Logger will delete old logs to make room for new ones.
worklight.js:5356 Piggybacking event transmission
worklight.js:5356 Flush called

编辑2

以下是项目及其资源的链接：

Answer 1

更新：

您遇到的问题是因为JS无法处理二进制数据。最好的选择是在后端服务器上对文件进行 base64 编码，然后在保存到文件之前在应用程序上对文件进行 base64 解码。例如：

后端服务器：

您的项目需要额外的依赖项import org.apache.commons.codec.binary.Base64;

@POST
@Consumes(MediaType.APPLICATION_JSON)
@Produces("application/pdf")
public Response downloads() throws IOException {

    File file = new File("myFile.pdf");

    InputStream fileStream = new FileInputStream(file);

    byte[] data = new byte[1024];

    ByteArrayOutputStream buffer = new ByteArrayOutputStream();

    int read = 0;
    while ((read = fileStream.read(data, 0, data.length)) != -1) {
        buffer.write(data, 0, read);
    }

    buffer.flush();

    fileStream.close();

    ResponseBuilder response = Response.ok(Base64.encodeBase64(buffer.toByteArray()));
    response.header("Content-Disposition", "attachment; filename=myFile.pdf");
    Response responseBuilder = response.build();
    return responseBuilder;
}

通过 MobileFirst Adapter 下载 PDF 文件

Download PDF file from through MobileFirst Adapter

java

ibm-mobilefirst

mobilefirst-adapters