Integrate Amazon S3(Simple Storage Service) into WaveMaker App

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Learn how to implement file upload, download and delete file on S3 bucket using AWS S3 Connector.

AWS S3 Connector

Amazon S3 (Simple Storage Service) is a scalable, high-speed, low-cost web-based service designed for online backup and archiving of data and application programs. It allows to upload, store, and download any type of files up to 5 TB in size. This service allows the subscribers to access the same systems that Amazon uses to run its own web sites. The subscriber has control over the accessibility of data, i.e. privately/publicly accessible.

This connector exposes api to interact with AWS S3 from WaveMaker application.

Step 1: Importing the aws-s3-connector to project

1. Download the latest aws-s3-connector zip here
2. Import the downloaded aws-s3-connector zip into your app using the Import Resource option to the Connector folder.

Step 2: Configure aws-s3-connector properties in profiles

1. By default externalized connector properties are added in the project profiles Know More.
2. Connector externalized properties are prefixed with connector.${connectorName}

connector.aws-s3-connector.default.aws.accessKey=
connector.aws-s3-connector.default.aws.accessSecret=
connector.aws-s3-connector.default.aws.clientRegion=
connector.aws-s3-connector.default.aws.bucketName=

Step3: Perform File Operations in Storage Account.

Autowire the Connector Service into the added JavaService.

Import Statement:

import com.wavemaker.connector.awss3connector.S3Connector;

@Autowired
private S3Connector s3Connector;

1. Upload file to Amazon S3 bucket.

Uploads a new file object to the specified Amazon S3 bucket.

Import statements required:

import org.springframework.web.multipart.MultipartFile;
import java.io.IOException; 

Source Code:

public void uploadFile(MultipartFile file){
    try{
        s3Connector.uploadFileToS3(file.getInputStream(),file.getOriginalFilename(), null);
    } catch (IOException e) {
        throw new RuntimeException("Exception occurred while uploading file: "+e);
    }
}

note

The third param for upload API is the custom metadata. Add the key value pairs of the custom user-metadata for the associated file object. If the entry in the custom user-metadata map already contains the specified key, it will be replaced with these new contents.

2. List files from Amazon S3.

Returns a list of summary information about the objects in the specified bucket.

Import statements required:

import com.wavemaker.connector.awss3connector.AWSS3ObjectSummary;
import java.util.List;

Source Code:

public List<AWSS3ObjectSummary> listObjects(){
    return s3Connector.listS3Objects();
}

3. Download file from S3.

Gets the object from Amazon S3 under the specified bucket.

Import statements required:

import com.wavemaker.runtime.file.model.DownloadResponse;
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;
import java.io.ByteArrayInputStream;

Source Code:

public DownloadResponse downloadFile(String s3KeyName){
    try{
        OutputStream data= s3Connector.downloadFile(s3KeyName);
        DownloadResponse downloadResponse=new DownloadResponse();
        ByteArrayOutputStream outStream = (ByteArrayOutputStream)data;
        downloadResponse.setContents(new ByteArrayInputStream(outStream.toByteArray()));
        downloadResponse.setInline(false);
        downloadResponse.setFileName(s3KeyName);
        return downloadResponse;
        }catch(IOException e){
            throw new RuntimeException("Exception occurred while downloading file"+e);
        }
    }

4. Delete file in S3.

Deletes the specified object in the specified bucket.

Source Code:

public void deleteFile(String s3KeyName){
    s3Connector.deleteFile(s3KeyName);
}

note

s3KeyName is the file key name. Example: IMG_20200202.jpg