一、使用AngularJS上傳檔案

• 前臺是Angular頁面
• 後臺使用SpringBoot/SpirngMVC

上傳檔案

• html

<div>
    <input id="fileUpload" type="file" />
    <button ng-click="uploadFile()">上傳</button>
</div>

• js

 $scope.upload = function(){
            var form = new FormData();
            var file = document.getElementById("fileUpload").files[0];
            form.append('file', file);
            $http({
                method: 'POST',
                url: '/upload',
                data: form,
                headers: {'Content-Type': undefined},
                transformRequest: angular.identity
            }).success(function (data) {
                console.log('upload success');
            }).error(function (data) {
                 console.log('upload fail');
            })
        }
 

注意：

• AngularJS預設的'Content-Type'是application/json ，通過設定'Content-Type': undefined，這樣瀏覽器不僅幫我們把Content-Type 設定為 multipart/form-data，還填充上當前的boundary，
• 如果手動設定為：'Content-Type': multipart/form-data，後臺會丟擲異常：the request was rejected because no multipart boundary was found
• boundary 是隨機生成的字串，用來分隔文字的開始和結束
• 通過設定 transformRequest: angular.identity ，anjularjs transformRequest function 將序列化我們的formdata object，也可以不新增

• 後臺

@RequestMapping("/upload")
    public void uploadFile(@RequestParam(value = "file" , required = true) MultipartFile file) {
        //deal with file
    }
 

 注意：

• 檔案必須通過@RequestParam註解來獲取，且需指定value才能獲取到

•  這樣就完成了上傳檔案

上傳檔案的同時傳遞其他引數

• html

    <div>
        <input id="fileUpload" type="file" />
        <button ng-click="ok()">上傳</button><br>
        <input ng-model="user.username" />
        <input ng-model="user.password" />
    </div>

    $scope.ok = function () {
        var form = new FormData();
        var file = document.getElementById("fileUpload").files[0];   
        var user =JSON.stringify($scope.user);

        form.append('file', file);
        form.append('user',user);

        $http({
            method: 'POST',
            url: '/addUser',
            data: form,
            headers: {'Content-Type': undefined},
            transformRequest: angular.identity
        }).success(function (data) {
            console.log('operation success');
        }).error(function (data) {
            console.log('operation fail');
        })
    };

• js

$scope.ok = function () {
        var form = new FormData();
        var file = document.getElementById("fileUpload").files[0];   
        var user =JSON.stringify($scope.user);

        form.append('file', file);
        form.append('user',user);

        $http({
            method: 'POST',
            url: '/addUser',
            data: form,
            headers: {'Content-Type': undefined},
            transformRequest: angular.identity
        }).success(function (data) {
            console.log('operation success');
        }).error(function (data) {
            console.log('operation fail');
        })
    };

注意 

• 需要將Object轉為String後在附加到form上，否則會直接被轉為字串[Object,object]

• 後臺

 @RequestMapping("/upload")
    public Map<String, Object> upload(@RequestParam(value = "file") MultipartFile file, @RequestParam(value = "user", required = true) String user) {

        try (FileInputStream in = (FileInputStream) headImg.getInputStream();
             FileOutputStream out = new FileOutputStream("filePathAndName")) {

            //將Json物件解析為UserModel物件
            ObjectMapper objectMapper = new ObjectMapper();
            UserModel userModel = objectMapper.readValue(user, UserModel.class);

            //儲存檔案到filePathAndName
            int hasRead = 0;
            byte[] bytes = new byte[1024];
            while ((hasRead = in.read(bytes)) > 0) {
                out.write(bytes, 0, hasRead);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

注意

• ObjectMapper為com.fasterxml.jackson.databind.ObjectMapper