简体   繁体   English

通过Google App Engine(Java)将文件上传到Google云端存储

[英]Upload file to Google cloud storage from Google App Engine (Java)

How can I upload file from servlet in google app engine to google cloud storage? 如何将文件从谷歌应用引擎中的servlet上传到谷歌云存储?

When I did it, Google cloud storage didn't know the type of the file, the file I send from an HTML form. 当我这样做时,谷歌云存储不知道文件的类型,我从HTML表单发送的文件。 What is the correct way to write HTML/JavaScript and servlet to upload a file to cloud storage? 编写HTML / JavaScript和servlet以将文件上传到云存储的正确方法是什么?

Below is a code example from Google for interacting with the Cloud Storage in Java Script. 以下是Google提供的与Java Script中的云存储交互的代码示例。 It does much more than uploading, ie you can download, create new bucket, etc. Below I've added the function I use to upload which is derived from this example. 它不仅仅是上传,即你可以下载,创建新的存储桶等。下面我添加了我用来上传的功能,这个功能是从这个例子中得到的。

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset='utf-8' />
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
    <script src="https://apis.google.com/js/client.js"></script>
    <script type="text/javascript">
        /**
         * The Project ID of your Google Cloud Storage Project.
         */
        var PROJECT = 'abcd';
        /**
         * Enter a client ID for a web application from the Google Developers
         * Console on the "APIs & auth", "Credentials" page.
         * In your Developers Console project add a JavaScript origin
         * that corresponds to the domain from where you will be running the
         * script. For more info see:
         * https://developers.google.com/console/help/new/#generatingoauth2
         */
        var clientId = '701111116470-55bj2lkjlkkjkljhe97di22gus5hs3.apps.googleusercontent.com';
        /**
         * Enter the API key from the Google Developers Console, by following these
         * steps:
         * 1) Visit https://cloud.google.com/console and select your project
         * 2) Click on "APIs & auth" in the left column and then click “Credentials”
         * 3) Find section "Public API Access" and use the "API key." If sample is
         * being run on localhost then delete all "Referers" and save. Setting
         * should display "Any referer allowed." For more info see:
         * https://developers.google.com/console/help/new/#generatingdevkeys
         */
        var apiKey = 'JHJhhguy8786875hghgjbS0nYjcMY';
        /**
         * To enter one or more authentication scopes, refer to the documentation
         * for the API.
         */
        var scopes = 'https://www.googleapis.com/auth/devstorage.full_control';
        /**
         * Constants for request parameters. Fill these values in with your custom
         * information.
         */
        var API_VERSION = 'v1';
        /**
         * Enter a unique bucket name to create a new bucket. The guidelines for
         * bucket naming can be found here:
         * https://developers.google.com/storage/docs/bucketnaming
         */
        //var BUCKET = 'code-sample-bucket-' + Date.now();
        var BUCKET = 'testbucket';
        /**
         * The name of the object inserted via insertObject method.
         */
        var object = "";
        /**
         * Get this value from the Developers Console. Click on the
         * “Cloud Storage” service in the Left column and then select
         * “Project Dashboard”. Use one of the Google Cloud Storage group IDs
         * listed and combine with the prefix “group-” to get a string
         * like the example below.
         */
        var GROUP =
                'group-kjhHJKHJKH897897878jgjghg8728f21c3ff22597efbfc63ccdb8f2294d8fd2561cb9';
        /**
         * Valid values are user-userId, user-email, group-groupId, group-email,
         * allUsers, allAuthenticatedUsers
         */
        var ENTITY = 'allUsers';
        /**
         * Valid values are READER, OWNER
         */
        var ROLE = 'READER';
        /**
         * Valid values are READER, OWNER
         */
        var ROLE_OBJECT = 'READER';
        /**
         * A list of example calls to the Google Cloud Storage JavaScript client
         * library, as well as associated explanations of each call.
         */
        var listApiRequestExplanations = {
            'listBuckets': 'This API call queries the Google Cloud Storage API ' +
            'for a list of buckets in your project, and returns the result as ' +
            'a list of Google Cloud Storage buckets.',
            'listObjects': 'This API call queries the Google Cloud Storage API ' +
            'for a list of objects in your bucket, and returns the result as ' +
            'a list of Google Cloud Storage objects.',
            'listBucketsAccessControls': 'This API call queries the Google Cloud ' +
            'Storage API for the list of access control lists on buckets in your ' +
            'project and returns the result as a list of Google Cloud Storage ' +
            'Access Control Lists.',
            'listObjectsAccessControls': 'This API call queries the Google Cloud ' +
            'Storage API for the list of access control lists on objects in your ' +
            'bucket and returns the result as a list of Google Cloud Storage ' +
            'Access Control Lists.',
            'getBucket': 'This API call queries the Google Cloud Storage API ' +
            'for a bucket in your project, and returns the result as a ' +
            'Google Cloud Storage bucket.',
            'getBucketAccessControls': 'This API call queries the Google Cloud ' +
            'Storage API for the access control list on a specific bucket ' +
            'and returns the result as a Google Cloud Storage Access Control List.',
            'getObjectAccessControls': 'This API call queries the Google Cloud ' +
            'Storage API for the access control list on a specific object ' +
            'and returns the result as a Google Cloud Storage Access Control List.',
            'insertBucket': 'This API call uses the Google Cloud Storage API ' +
            'to insert a bucket into your project.',
            'insertObject': 'This API call uses the Google Cloud Storage API ' +
            'to insert an object into your bucket.',
            'insertBucketAccessControls': 'This API uses the Google Cloud ' +
            'Storage API to insert an access control list on a specific bucket ' +
            'and returns the result as a Google Cloud Storage Access Control List.',
            'insertObjectAccessControls': 'This API uses the Google Cloud ' +
            'Storage API to insert an access control list on a specific object ' +
            'and returns the result as a Google Cloud Storage Access Control List.',
            'deleteBucket': 'This API uses the Google Cloud Storage API to delete ' +
            'an empty bucket and returns an empty response to indicate success.',
            'deleteObject': 'This API uses the Google Cloud Storage API to delete ' +
            'an object and returns an empty response to indicate success.'
        };
        /**
         * Google Cloud Storage API request to retrieve the list of buckets in
         * your Google Cloud Storage project.
         */
        function listBuckets() {
            var request = gapi.client.storage.buckets.list({
                'project': PROJECT
            });
            executeRequest(request, 'listBuckets');
        }
        /**
         * Google Cloud Storage API request to retrieve the list of objects in
         * your Google Cloud Storage project.
         */
        function listObjects() {
            var request = gapi.client.storage.objects.list({
                'bucket': BUCKET
            });
            executeRequest(request, 'listObjects');
        }
        /**
         * Google Cloud Storage API request to retrieve the access control list on
         * a bucket in your Google Cloud Storage project.
         */
        function listBucketsAccessControls() {
            var request = gapi.client.storage.bucketAccessControls.list({
                'bucket': BUCKET
            });
            executeRequest(request, 'listBucketsAccessControls');
        }
        /**
         * Google Cloud Storage API request to retrieve the access control list on
         * an object in your Google Cloud Storage project.
         */
        function listObjectsAccessControls() {
            var request = gapi.client.storage.objectAccessControls.list({
                'bucket': BUCKET,
                'object': object
            });
            executeRequest(request, 'listObjectsAccessControls');
        }
        /**
         * Google Cloud Storage API request to retrieve a bucket in
         * your Google Cloud Storage project.
         */
        function getBucket() {
            var request = gapi.client.storage.buckets.get({
                'bucket': BUCKET
            });
            executeRequest(request, 'getBucket');
        }
        /**
         * Google Cloud Storage API request to retrieve a bucket's Access Control
         * List in your Google Cloud Storage project.
         */
        function getBucketAccessControls() {
            var request = gapi.client.storage.bucketAccessControls.get({
                'bucket': BUCKET,
                'entity': GROUP
            });
            executeRequest(request, 'getBucketAccessControls');
        }
        /**
         * Google Cloud Storage API request to retrieve an object's Access Control
         * List in your Google Cloud Storage project.
         */
        function getObjectAccessControls() {
            var request = gapi.client.storage.objectAccessControls.get({
                'bucket': BUCKET,
                'object': object,
                'entity': GROUP
            });
            executeRequest(request, 'getObjectAccessControls');
        }
        /**
         * Google Cloud Storage API request to insert a bucket into
         * your Google Cloud Storage project.
         */
        function insertBucket() {
            resource = {
                'name': BUCKET
            };
            var request = gapi.client.storage.buckets.insert({
                'project': PROJECT,
                'resource': resource
            });
            executeRequest(request, 'insertBucket');
        }
        /**
         * Google Cloud Storage API request to insert an object into
         * your Google Cloud Storage bucket.
         */
        function insertObject(event) {
            try{
                var fileData = event.target.files[0];
            }
            catch(e) {
                //'Insert Object' selected from the API Commands select list
                //Display insert object button and then exit function
                filePicker.style.display = 'block';
                return;
            }
            const boundary = '-------314159265358979323846';
            const delimiter = "\r\n--" + boundary + "\r\n";
            const close_delim = "\r\n--" + boundary + "--";
            var reader = new FileReader();
            reader.readAsBinaryString(fileData);
            reader.onload = function(e) {
                var contentType = fileData.type || 'application/octet-stream';
                var metadata = {
                    'name': fileData.name,
                    'mimeType': contentType
                };
                var base64Data = btoa(reader.result);
                var multipartRequestBody =
                        delimiter +
                        'Content-Type: application/json\r\n\r\n' +
                        JSON.stringify(metadata) +
                        delimiter +
                        'Content-Type: ' + contentType + '\r\n' +
                        'Content-Transfer-Encoding: base64\r\n' +
                        '\r\n' +
                        base64Data +
                        close_delim;
                //Note: gapi.client.storage.objects.insert() can only insert
                //small objects (under 64k) so to support larger file sizes
                //we're using the generic HTTP request method gapi.client.request()
                var request = gapi.client.request({
                    'path': '/upload/storage/' + API_VERSION + '/b/' + BUCKET + '/o',
                    'method': 'POST',
                    'params': {'uploadType': 'multipart'},
                    'headers': {
                        'Content-Type': 'multipart/mixed; boundary="' + boundary + '"'
                    },
                    'body': multipartRequestBody});
                //Remove the current API result entry in the main-content div
                listChildren = document.getElementById('main-content').childNodes;
                if (listChildren.length > 1) {
                    listChildren[1].parentNode.removeChild(listChildren[1]);
                }
                try{
                    //Execute the insert object request
                    executeRequest(request, 'insertObject');
                    //Store the name of the inserted object
                    object = fileData.name;
                }
                catch(e) {
                    alert('An error has occurred: ' + e.message);
                }
            }
        }
        /**
         * Google Cloud Storage API request to insert an Access Control List into
         * your Google Cloud Storage bucket.
         */
        function insertBucketAccessControls() {
            resource = {
                'entity': ENTITY,
                'role': ROLE
            };
            var request = gapi.client.storage.bucketAccessControls.insert({
                'bucket': BUCKET,
                'resource': resource
            });
            executeRequest(request, 'insertBucketAccessControls');
        }
        /**
         * Google Cloud Storage API request to insert an Access Control List into
         * your Google Cloud Storage object.
         */
        function insertObjectAccessControls() {
            resource = {
                'entity': ENTITY,
                'role': ROLE_OBJECT
            };
            var request = gapi.client.storage.objectAccessControls.insert({
                'bucket': BUCKET,
                'object': object,
                'resource': resource
            });
            executeRequest(request, 'insertObjectAccessControls');
        }
        /**
         * Google Cloud Storage API request to delete a Google Cloud Storage bucket.
         */
        function deleteBucket() {
            var request = gapi.client.storage.buckets.delete({
                'bucket': BUCKET
            });
            executeRequest(request, 'deleteBucket');
        }
        /**
         * Google Cloud Storage API request to delete a Google Cloud Storage object.
         */
        function deleteObject() {
            var request = gapi.client.storage.objects.delete({
                'bucket': BUCKET,
                'object': object
            });
            executeRequest(request, 'deleteObject');
        }
        /**
         * Removes the current API result entry in the main-content div, adds the
         * results of the entry for your function.
         * @param {string} apiRequestName The name of the example API request.
         */
        function updateApiResultEntry(apiRequestName) {
            listChildren = document.getElementById('main-content')
                    .childNodes;
            if (listChildren.length > 1) {
                listChildren[1].parentNode.removeChild(listChildren[1]);
            }
            if (apiRequestName != 'null') {
                window[apiRequestName].apply(this);
            }
        }
        /**
         * Determines which API request has been selected, and makes a call to add
         * its result entry.
         */
        function runSelectedApiRequest() {
            var curElement = document.getElementById('api-selection-options');
            var apiRequestName = curElement.options[curElement.selectedIndex].value;
            updateApiResultEntry(apiRequestName);
        }
        /**
         * Binds event listeners to handle a newly selected API request.
         */
        function addSelectionSwitchingListeners() {
            document.getElementById('api-selection-options')
                    .addEventListener('change',
                    runSelectedApiRequest, false);
        }
        /**
         * Template for getting JavaScript sample code snippets.
         * @param {string} method The name of the Google Cloud Storage request
         * @param {string} params The parameters passed to method
         */
        function getCodeSnippet(method, params) {
            var objConstruction = "// Declare your parameter object\n";
            objConstruction += "var params = {};";
            objConstruction += "\n\n";
            var param = "// Initialize your parameters \n";
            for (i in params) {
                param += "params['" + i + "'] = ";
                param += JSON.stringify(params[i], null, '\t');
                param += ";";
                param += "\n";
            }
            param += "\n";
            var methodCall = "// Make a request to the Google Cloud Storage API \n";
            methodCall += "var request = gapi.client." + method + "(params);";
            return objConstruction + param + methodCall;
        }
        /**
         * Executes your Google Cloud Storage request object and, subsequently,
         * inserts the response into the page.
         * @param {string} request A Google Cloud Storage request object issued
         *    from the Google Cloud Storage JavaScript client library.
         * @param {string} apiRequestName The name of the example API request.
         */
        function executeRequest(request, apiRequestName) {
            request.execute(function(resp) {
                console.log(resp);
                var apiRequestNode = document.createElement('div');
                apiRequestNode.id = apiRequestName;
                var apiRequestNodeHeader = document.createElement('h2');
                apiRequestNodeHeader.innerHTML = apiRequestName;
                var apiRequestExplanationNode = document.createElement('div');
                apiRequestExplanationNode.id = apiRequestName + 'RequestExplanation';
                var apiRequestExplanationNodeHeader = document.createElement('h3');
                apiRequestExplanationNodeHeader.innerHTML = 'API Request Explanation';
                apiRequestExplanationNode.appendChild(apiRequestExplanationNodeHeader);
                var apiRequestExplanationEntry = document.createElement('p');
                apiRequestExplanationEntry.innerHTML =
                        listApiRequestExplanations[apiRequestName];
                apiRequestExplanationNode.appendChild(apiRequestExplanationEntry);
                apiRequestNode.appendChild(apiRequestNodeHeader);
                apiRequestNode.appendChild(apiRequestExplanationNode);
                var apiRequestCodeSnippetNode = document.createElement('div');
                apiRequestCodeSnippetNode.id = apiRequestName + 'CodeSnippet';
                var apiRequestCodeSnippetHeader = document.createElement('h3');
                apiRequestCodeSnippetHeader.innerHTML = 'API Request Code Snippet';
                apiRequestCodeSnippetNode.appendChild(apiRequestCodeSnippetHeader);
                var apiRequestCodeSnippetEntry = document.createElement('pre');
                //If the selected API command is not 'insertObject', pass the request
                //paramaters to the getCodeSnippet method call as 'request.wc.wc.params'
                //else pass request paramaters as 'request.wc.wc'


/*                if (apiRequestName != 'insertObject') {
                    apiRequestCodeSnippetEntry.innerHTML =
                            getCodeSnippet(request.wc.wc.method, request.wc.wc.params);
                    //Selected API Command is not 'insertObject'
                    //hide insert object button
                    filePicker.style.display = 'none';
                } else {
                    apiRequestCodeSnippetEntry.innerHTML =
                            getCodeSnippet(request.wc.wc.method, request.wc.wc);
                }*/


                apiRequestCodeSnippetNode.appendChild(apiRequestCodeSnippetEntry);
                apiRequestNode.appendChild(apiRequestCodeSnippetNode);
                var apiResponseNode = document.createElement('div');
                apiResponseNode.id = apiRequestName + 'Response';
                var apiResponseHeader = document.createElement('h3');
                apiResponseHeader.innerHTML = 'API Response';
                apiResponseNode.appendChild(apiResponseHeader);
                var apiResponseEntry = document.createElement('pre');
                apiResponseEntry.innerHTML = JSON.stringify(resp, null, ' ');
                apiResponseNode.appendChild(apiResponseEntry);
                apiRequestNode.appendChild(apiResponseNode);
                var content = document.getElementById('main-content');
                content.appendChild(apiRequestNode);
            });
        }
        /**
         * Set required API keys and check authentication status.
         */
        function handleClientLoad() {
            gapi.client.setApiKey(apiKey);
            window.setTimeout(checkAuth, 1);
        }
        /**
         * Authorize Google Cloud Storage API.
         */
        function checkAuth() {
            gapi.auth.authorize({
                client_id: clientId,
                scope: scopes,
                immediate: true
            }, handleAuthResult);
        }
        /**
         * Handle authorization.
         */
        function handleAuthResult(authResult) {
            var authorizeButton = document.getElementById('authorize-button');
            if (authResult && !authResult.error) {
                authorizeButton.style.visibility = 'hidden';
                initializeApi();
                filePicker.onchange = insertObject;
            } else {
                authorizeButton.style.visibility = '';
                authorizeButton.onclick = handleAuthClick;
            }
        }
        /**
         * Handle authorization click event.
         */
        function handleAuthClick(event) {
            gapi.auth.authorize({
                client_id: clientId,
                scope: scopes,
                immediate: false
            }, handleAuthResult);
            return false;
        }
        /**
         * Load the Google Cloud Storage API.
         */
        function initializeApi() {
            gapi.client.load('storage', API_VERSION);
        }
        /**
         * Driver for sample application.
         */
        $(window)
                .bind('load', function() {
                    addSelectionSwitchingListeners();
                    handleClientLoad();
                });
    </script>
</head>
<body>
<!--Add a button for the user to click to initiate auth sequence -->
<button id="authorize-button" style="visibility: hidden">Authorize</button>
<header>
    <h1>Google Cloud Storage JavaScript Client Library Application</h1>
</header>
<label id="api-label">Try a sample API call!</label>
<select id="api-selection-options">
    <option value="null">
        Please select an example API call from the dropdown menu
    </option>
    <option value="listBuckets">
        List Buckets
    </option>
    <option value="insertBucket">
        Insert Bucket
    </option>
    <option value="getBucket">
        Get Bucket
    </option>
    <option value="getBucketAccessControls">
        Get Bucket Access Controls
    </option>
    <option value="insertBucketAccessControls">
        Insert Bucket Access Controls
    </option>
    <option value="listBucketsAccessControls">
        List Buckets Access Control List
    </option>
    <option value="insertObject">
        Insert Object
    </option>
    <option value="listObjects">
        List Objects
    </option>
    <option value="getObjectAccessControls">
        Get Object Access Controls
    </option>
    <option value="insertObjectAccessControls">
        Insert Object Access Controls
    </option>
    <option value="listObjectsAccessControls">
        List Objects Access Control List
    </option>
    <option value="deleteObject">
        Delete Object
    </option>
    <option value="deleteBucket">
        Delete Bucket
    </option>
</select>
<br/>
<input type="file" id="filePicker" style="display: none" />
<div id="main-content">
</div>
</body>
</html>

Below is the function to upload a file, fully inspired from the example above. 下面是上传文件的功能,完全受上面例子的启发。 Note that it uses the JavaScript client library to interact with Google API (gapi), which means that you can secure the upload with authentication via google accounts ( https://developers.google.com/api-client-library/javascript/start/start-js ). 请注意,它使用JavaScript客户端库与Google API(gapi)进行交互,这意味着您可以通过Google帐户进行身份验证来保护上传( https://developers.google.com/api-client-library/javascript/start / start-js )。

function uploadFile(fileData, bucket) {
    var boundary = '-------314159265358979323846';
    var delimiter = "\r\n--" + boundary + "\r\n";
    var close_delim = "\r\n--" + boundary + "--";
    var reader = new FileReader();
    reader.readAsBinaryString(fileData);

    reader.onload = function (e) {
        var contentType = fileData.type || 'application/octet-stream';
        var metadata = {
            'name': fileData.name,
            'mimeType': contentType
        };
        var base64Data = btoa(reader.result);
        var multipartRequestBody =
                delimiter +
                'Content-Type: application/json\r\n\r\n' +
                JSON.stringify(metadata) +
                delimiter +
                'Content-Type: ' + contentType + '\r\n' +
                'Content-Transfer-Encoding: base64\r\n' +
                '\r\n' +
                base64Data +
                close_delim;

        var request = gapi.client.request({
            'path': '/upload/storage/v1/b/' + bucket + '/o',
            'method': 'POST',
            'params': {'uploadType': 'multipart'},
            'headers': {
                'Content-Type': 'multipart/mixed; boundary="' + boundary + '"'
            },
            'body': multipartRequestBody
        });

        try {
            request.execute(function (resp) {
                if (resp.hasOwnProperty("error")) {
                    //Treat Error
                } else {
                    //Treat Success
                }
            });
        }
        catch (e) {
            //Treat Error
        }

    };

}

Finally, you can use the Object Change Notification of Cloud Storage to call a task in App engine. 最后,您可以使用云存储的对象更改通知来调用App引擎中的任务。 You can pass the bucket and file name and treat the file that was just uploaded via App Engine. 您可以传递存储桶和文件名,并处理刚通过App Engine上传的文件。 https://cloud.google.com/storage/docs/object-change-notification https://cloud.google.com/storage/docs/object-change-notification

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM