没有文件被发送到SAP Leonardo图像特征提取API使用FormData

Question

我正在测试SAP Leonardo图像特征提取API（https://sandbox.api.sap.com/ml/featureextraction/inference_sync）。我有图像的bas64字符串，我想将其转换为文件对象并压缩，然后使用XMLHttpRequest将压缩后的图像文件发送到该API。但是响应文本是“服务需要（压缩）图像列表”。

我在下面的截图中附上我的HTTP请求头和参数。

虽然我们在参数中看到了混乱的代码，但这里的压缩文件下载成功创建。

如果无法下载压缩文件，请参考下面的屏幕截图。

一切似乎都很好。然而，回复文本如下，状态为400。

我的javascript代码如下所示。怎么了？这让我疯狂。。。

js lang-js prettyprint-override">dataURItoBlob: function(dataURI, fileName) {
	//convert base64/URLEncoded data component to raw binary data held in a string
	var byteString;
	if (dataURI.split(',')[0].indexOf('base64') >= 0)
		byteString = atob(dataURI.split(',')[1]);
	else
		byteString = unescape(dataURI.split(',')[1]);
	
	//separate out the mime component
	var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
	
	//write the bytes of the string to a typed array
	var ia = new Uint8Array(byteString.length);
	for (var i = 0; i < byteString.length; i++) {
		ia[i] = byteString.charCodeAt(i);
	}
	
	var blob = new Blob([ia], {encoding:"UTF-8",type:mimeString});
	//A Blob() is almost a File() - it's just missing the two properties below which we will add
	blob.lastModifiedDate = new Date();
	blob.name = fileName + '.' + mimeString.split('/')[1];
	
	return blob;
},

onSubmit: function(oEvent) {
	var oImage = this.getView().byId('myImage');
	//oImage.getSrc() : 'data:image/png;base64,iVBORw0KGgo...'
	var imageFile = this.dataURItoBlob(oImage.getSrc(), 'myImage');
	var zip = new JSZip();
	zip.file(imageFile.name, imageFile);
	
	zip.generateAsync({
		type:"blob",
		compression: 'DEFLATE', // force a compression for this file
		compressionOptions: {
			level: 6,
	    },
	}).then(function(content) {
		//saveAs(content, "hello.zip");
		// start the busy indicator
		var oBusyIndicator = new sap.m.BusyDialog();
		oBusyIndicator.open();
		
		var formData = new FormData();
		formData.append('files', content, 'myImage.zip');
		
		var xhr = new XMLHttpRequest();
		xhr.withCredentials = false;
		
		xhr.addEventListener("readystatechange", function () {
			if (this.readyState === this.DONE) {
				oBusyIndicator.close();
				//navigator.notification.alert(this.responseText);
				console.log(this.responseText);
			}
		});

		//setting request method
		//API endpoint for API sandbox
		//Destionation '/SANDBOX_API' in HCP is configured as 'https://sandbox.api.sap.com'
		var api = "/SANDBOX_API/ml/featureextraction/inference_sync";
		xhr.open("POST", api);

		//adding request headers
		xhr.setRequestHeader("Content-Type", "multipart/form-data");
		xhr.setRequestHeader("Accept", "application/json");
		//API Key for API Sandbox
		xhr.setRequestHeader("APIKey", "yQd5Oy785NkAIob6g1eNwctBg4m1LGQS");

		//sending request
		xhr.send(formData);
	});
	
},

Answer 1

我自己解决这个问题。我提出我的解决方案只是为了让别人知道。这很简单，在发送请求之前只需删除下面的代码。我不知道为什么。如果你知道原因，请提出建议。提前谢谢！

xhr.setRequestHeader("Content-Type", "multipart/form-data");