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? When I did it, Google cloud storage didn't know the type of the file, the file I send from an HTML
Solution 1:
Below is a code example from Google for interacting with the Cloud Storage in Java Script. It does much more than uploading, i.e. you can download, create new bucket, etc. Below I've added the function I use to upload which is derived from this example.
<!DOCTYPE html><html><headlang="en"><metacharset='utf-8' /><scriptsrc="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script><scriptsrc="https://apis.google.com/js/client.js"></script><scripttype="text/javascript">/**
* The Project ID of your Google Cloud Storage Project.
*/varPROJECT = '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.
*/varAPI_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();varBUCKET = '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.
*/varGROUP =
'group-kjhHJKHJKH897897878jgjghg8728f21c3ff22597efbfc63ccdb8f2294d8fd2561cb9';
/**
* Valid values are user-userId, user-email, group-groupId, group-email,
* allUsers, allAuthenticatedUsers
*/varENTITY = 'allUsers';
/**
* Valid values are READER, OWNER
*/varROLE = 'READER';
/**
* Valid values are READER, OWNER
*/varROLE_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.
*/functionlistBuckets() {
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.
*/functionlistObjects() {
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.
*/functionlistBucketsAccessControls() {
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.
*/functionlistObjectsAccessControls() {
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.
*/functiongetBucket() {
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.
*/functiongetBucketAccessControls() {
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.
*/functiongetObjectAccessControls() {
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.
*/functioninsertBucket() {
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.
*/functioninsertObject(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 = newFileReader();
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 requestexecuteRequest(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.
*/functioninsertBucketAccessControls() {
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.
*/functioninsertObjectAccessControls() {
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.
*/functiondeleteBucket() {
var request = gapi.client.storage.buckets.delete({
'bucket': BUCKET
});
executeRequest(request, 'deleteBucket');
}
/**
* Google Cloud Storage API request to delete a Google Cloud Storage object.
*/functiondeleteObject() {
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.
*/functionupdateApiResultEntry(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.
*/functionrunSelectedApiRequest() {
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.
*/functionaddSelectionSwitchingListeners() {
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
*/functiongetCodeSnippet(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.
*/functionexecuteRequest(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.
*/functionhandleClientLoad() {
gapi.client.setApiKey(apiKey);
window.setTimeout(checkAuth, 1);
}
/**
* Authorize Google Cloud Storage API.
*/functioncheckAuth() {
gapi.auth.authorize({
client_id: clientId,
scope: scopes,
immediate: true
}, handleAuthResult);
}
/**
* Handle authorization.
*/functionhandleAuthResult(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.
*/functionhandleAuthClick(event) {
gapi.auth.authorize({
client_id: clientId,
scope: scopes,
immediate: false
}, handleAuthResult);
returnfalse;
}
/**
* Load the Google Cloud Storage API.
*/functioninitializeApi() {
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 --><buttonid="authorize-button"style="visibility: hidden">Authorize</button><header><h1>Google Cloud Storage JavaScript Client Library Application</h1></header><labelid="api-label">Try a sample API call!</label><selectid="api-selection-options"><optionvalue="null">
Please select an example API call from the dropdown menu
</option><optionvalue="listBuckets">
List Buckets
</option><optionvalue="insertBucket">
Insert Bucket
</option><optionvalue="getBucket">
Get Bucket
</option><optionvalue="getBucketAccessControls">
Get Bucket Access Controls
</option><optionvalue="insertBucketAccessControls">
Insert Bucket Access Controls
</option><optionvalue="listBucketsAccessControls">
List Buckets Access Control List
</option><optionvalue="insertObject">
Insert Object
</option><optionvalue="listObjects">
List Objects
</option><optionvalue="getObjectAccessControls">
Get Object Access Controls
</option><optionvalue="insertObjectAccessControls">
Insert Object Access Controls
</option><optionvalue="listObjectsAccessControls">
List Objects Access Control List
</option><optionvalue="deleteObject">
Delete Object
</option><optionvalue="deleteBucket">
Delete Bucket
</option></select><br/><inputtype="file"id="filePicker"style="display: none" /><divid="main-content"></div></body></html>Below is the function to upload a file, fully inspired from the example above. 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).
functionuploadFile(fileData, bucket) {
var boundary = '-------314159265358979323846';
var delimiter = "\r\n--" + boundary + "\r\n";
var close_delim = "\r\n--" + boundary + "--";
var reader = newFileReader();
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. You can pass the bucket and file name and treat the file that was just uploaded via App Engine. https://cloud.google.com/storage/docs/object-change-notification
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