getObject(bucketName: string, key: string)

Description

The getObject method retrieves an object from a specified S3 bucket. This is useful for accessing and reading the content stored in your S3 buckets.

Usage

const content = await this.s3Service.getObject('my-new-bucket', 'my-object-key');
console.log('Object content:', content);

Parameters

• bucketName: The name of the bucket where the object is stored.
• key: The key under which the object is stored.

Returns

• Promise<string | undefined>: A promise that resolves with the object content as a string, or undefined if the object does not exist.

Example Integration

Example 1: Basic Object Retrieval

This example demonstrates how to retrieve a simple text object from an S3 bucket using the getObject method.

import { Injectable } from '@nestjs/common';
import { S3Service } from '@open-nebel/nestjs-s3';

@Injectable()
export class MyService {
  constructor(private readonly s3Service: S3Service) {}

  async retrieveObject(): Promise<void> {
    try {
      const content = await this.s3Service.getObject('my-new-bucket', 'my-object-key');
      console.log('Object content:', content);
    } catch (error) {
      console.error('Error retrieving object:', error);
    }
  }
}

In this example:

• The MyService class uses the S3Service to retrieve a text object from the my-new-bucket bucket with the key my-object-key.
• The retrieveObject method logs the content of the object or logs an error if the retrieval fails.

Example 2: Retrieving JSON Data

This example demonstrates how to retrieve JSON data from an S3 bucket using the getObject method and parse it.

import { Injectable } from '@nestjs/common';
import { S3Service } from '@open-nebel/nestjs-s3';

@Injectable()
export class MyService {
  constructor(private readonly s3Service: S3Service) {}

  async retrieveJsonObject(bucketName: string, key: string): Promise<void> {
    try {
      const content = await this.s3Service.getObject(bucketName, key);
      if (content) {
        const data = JSON.parse(content);
        console.log('JSON data:', data);
      } else {
        console.log('Object not found.');
      }
    } catch (error) {
      console.error('Error retrieving JSON object:', error);
    }
  }
}

In this example:

• The MyService class retrieves a JSON object from the specified bucket and key.
• The content is parsed using JSON.parse and logged to the console.

Example 3: Handling Large Objects

This example demonstrates how to handle the retrieval of large objects from an S3 bucket.

import { Injectable } from '@nestjs/common';
import { S3Service } from '@open-nebel/nestjs-s3';

@Injectable()
export class MyService {
  constructor(private readonly s3Service: S3Service) {}

  async retrieveLargeObject(bucketName: string, key: string): Promise<void> {
    try {
      const content = await this.s3Service.getObject(bucketName, key);
      if (content) {
        // Process the large content as needed
        console.log('Large object content size:', content.length);
      } else {
        console.log('Object not found.');
      }
    } catch (error) {
      console.error('Error retrieving large object:', error);
    }
  }
}

In this example:

• The MyService class retrieves a large object from the specified bucket and key.
• The size of the object content is logged to the console.

Example 4: Retrieving Object with Error Handling

This example demonstrates enhanced error handling for object retrieval, capturing specific error codes and providing user-friendly messages.

import { Injectable } from '@nestjs/common';
import { S3Service } from '@open-nebel/nestjs-s3';

@Injectable()
export class MyService {
  constructor(private readonly s3Service: S3Service) {}

  async retrieveObjectWithEnhancedErrorHandling(bucketName: string, key: string): Promise<void> {
    try {
      const content = await this.s3Service.getObject(bucketName, key);
      if (content) {
        console.log('Object content:', content);
      } else {
        console.log('Object not found.');
      }
    } catch (error) {
      if (error.name === 'NoSuchKey') {
        console.error('The specified key does not exist.');
      } else {
        console.error('Error retrieving object:', error);
      }
    }
  }
}

In this example:

• The MyService class provides specific error handling for object retrieval.
• Different error scenarios (e.g., object not found) are handled with custom error messages.

Summary

The getObject method is essential for retrieving content from S3 buckets in AWS. With this method, you can access various types of data, including text, JSON objects, and large files. The provided examples show how to integrate this method into your NestJS application, demonstrating various use cases and handling common scenarios for robust application behavior.