{"id":19092,"date":"2015-04-20T23:11:33","date_gmt":"2015-04-20T17:41:33","guid":{"rendered":"http:\/\/www.tothenew.com\/blog\/?p=19092"},"modified":"2015-05-07T17:40:08","modified_gmt":"2015-05-07T12:10:08","slug":"file-upload-on-amazon-s3-server-via-html-form","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/file-upload-on-amazon-s3-server-via-html-form\/","title":{"rendered":"File Upload on Amazon S3 server via HTML Form"},"content":{"rendered":"

Use Case<\/strong> : \u00a0\u00a0File upload was require on web by end user which needs to be frequent and multiple at a time and if it goes through our tomcat server than it would be\u00a0overhead on server\u00a0. So for that we directly send the file to S3 server.<\/span><\/span><\/p>\n

We can upload file on Amazon S3 Server directly without routing the file through web\u00a0server by submitting\u00a0HTML form directly to S3 server with some configurations.<\/p>\n


\nFollowing are the Required Inputs<\/strong>:<\/h3>\n

<\/br><\/p>\n

    \n
  • Bucket name which is already created on S3.<\/span><\/li>\n
  • File which needs to be uploaded.<\/span><\/li>\n
  • ContentType is the type of file.<\/span><\/li>\n
  • Access Key of S3 server.<\/span><\/li>\n
  • Secret key of S3 Server.<\/span><\/li>\n
  • Base64 Encoded Signature by using S3 secret key .<\/span><\/li>\n
  • Expiration date in ISO 8601 UTC\u00a0format.<\/span><\/li>\n<\/ul>\n

    <\/br>
    \nA policy needs to be created which will have required conditions on the html form. There will be expiration date after which the upload form will no longer work.\u00a0HTML form must follow these\u00a0conditions to be submitted and also the elements of HTML form must be in a specific order.
    \nFirst we will create signature string using policy.
    \nThis string will be base 64 encoded using S3 secret key.<\/p>\n


    \nServer side code:<\/strong><\/h3>\n

    <\/br><\/p>\n

    \n

    import sun.misc.BASE64Encoder<\/span>
    \n import javax.crypto.Mac<\/span>
    \n import javax.crypto.spec.SecretKeySpec<\/span><\/p>\n

    String aws_bucket = “S3_BUCKET_NAME”<\/span>
    \n String aws_folderName = “ANY_FOLDER_NAME” \u00a0 \u00a0 \u00a0 \u00a0 \/\/ in which the file will be uploaded<\/span>
    \n String policy_document = “{ \\”expiration\\”: \\”EXPIRATION_DATE_IN_GMT_FORMAT\\”,” + \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/ 20016-12-01T12:00:00.000Z — date example in GMT<\/span>
    \n ” \\”conditions\\”: [” +<\/span>
    \n “{\\”acl\\”: \\”public-read\\” },” + \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/access control policy to apply to the uploaded file<\/span>
    \n “[\\”starts-with\\”, \\”\\$Content-Type\\”, \\”multipart\/form-data\\”],” + \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \/\/ starts-with : checks that\u00a0value begins with a given string<\/span>
    \n ” {\\”bucket\\”: \\”${aws_bucket}\\”},” +<\/span>
    \n “[\\”starts-with\\”, \\”\\$key\\”, \\”${aws_folderName}\/\\”]” +<\/span>
    \n ” ]” +<\/span>
    \n “}”<\/span>
    \n String aws_secret_key = “S3_SECRET_KEY”<\/span>
    \n String policy = (new BASE64Encoder()).encode(<\/span>
    \n policy_document.getBytes(“UTF-8”)).replaceAll(“\\n”, “”).replaceAll(“\\r”, “”);<\/span><\/p>\n

    Mac hmac = Mac.getInstance(“HmacSHA1”);<\/span>
    \n hmac.init(new SecretKeySpec(<\/span>
    \n aws_secret_key.getBytes(“UTF-8”), “HmacSHA1”));<\/span>
    \n String signature = (new BASE64Encoder()).encode(<\/span>
    \n hmac.doFinal(policy.getBytes(“UTF-8”)))<\/span>
    \n .replaceAll(“\\n”, “”);<\/span>
    \n String serverUrl = “http:\/\/${aws_bucket}.s3.amazonaws.com\/”<\/span>
    \n String accessKey = “S3_ACCESS_KEY”<\/span>
    \n String filePath = aws_folderName+”SOME_STRING_WHICH_WILL_BE_APPENDED_TO_FILE” \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/\u00a0this will be the path on S3 where file will be uploaded<\/span><\/p>\n<\/div>\n


    \nHTML form with GSP:<\/strong><\/h3>\n

     <\/p>\n

    Following form must be following all the conditions of policy document.
    \nFor our example : Key must be starting with “aws_folderName” , acl must be same , content type must starts with “multipart\/form-data”.<\/p>\n

    \n


    \n<form action=”${serverUrl}” name=”fileUploadForm” id=”fileUploadForm” method=”post”<\/span>
    \n enctype=”multipart\/form-data”><\/span>
    \n <input type=”hidden” name=”key” value=”${filePath+FILE_NAME}”\/><\/span>
    \n <input type=”hidden” name=”acl” value=”public-read”\/><\/span>
    \n <input type=”hidden” name=”Content-Type” value=”multipart\/form-data”\/><\/span>
    \n <input type=”hidden” name=”AWSAccessKeyId” value=”${accessKey}”\/><\/span>
    \n <input type=”hidden” name=”Policy” value=”${policy}”\/><\/span>
    \n <input type=”hidden” name=”Signature” value=”${signature}”\/><\/span>
    \n <input type=”file” name=”dataFile” id=”dataFile”\/><\/span>
    \n <\/form><\/span><\/p>\n

     <\/p><\/blockquote>\n

    <\/br><\/p>\n","protected":false},"excerpt":{"rendered":"

    Use Case : \u00a0\u00a0File upload was require on web by end user which needs to be frequent and multiple at a time and if it goes through our tomcat server than it would be\u00a0overhead on server\u00a0. So for that we directly send the file to S3 server. We can upload file on Amazon S3 Server […]<\/p>\n","protected":false},"author":180,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":6},"categories":[1174,7,446],"tags":[1763,1762,1764],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/19092"}],"collection":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/users\/180"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/comments?post=19092"}],"version-history":[{"count":0,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/19092\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/media?parent=19092"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/categories?post=19092"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/tags?post=19092"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}