How to Use Amazon Textract API for Document Analysis in Java

Integrate AWS SDK for Java

• Make sure to include the AWS SDK dependency in your project. You can do this through Maven by adding the necessary dependency in your `pom.xml` file. Below is an example of what to include:

<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>textract</artifactId>
    <version>2.x.y</version>
</dependency>

Set Up AWS Credentials

• AWS requires credentials to interact with Amazon Textract. Use the SDK's default credential provider chain, which looks for credentials in the following order:
• Environment Variables - `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`
• Java System Properties - `aws.accessKeyId` and `aws.secretKey`
• Default credential profiles file - typically located at `~/.aws/credentials`

Initialize the Textract Client

• Use the AWS SDK for Java to create the Textract client instance. The following code snippet demonstrates how to establish this connection:

import software.amazon.awssdk.services.textract.TextractClient;

TextractClient textractClient = TextractClient.builder()
        .build();

Prepare Your Document

• You must upload your document (PDF or image) to an S3 bucket. Amazon Textract processes documents from within the S3 environment.
• Ensure that the S3 bucket's permissions allow Textract to access it.

Call Amazon Textract API

• To invoke the Textract API for document analysis, utilize the `analyzeDocument` method from the client. Below is a code example illustrating this API call:

import software.amazon.awssdk.services.textract.model.*;

public AnalyzeDocumentResponse analyzeDocument() {
    S3Object s3Object = S3Object.builder()
            .bucket("your-s3-bucket-name")
            .name("your-document-key")
            .build();

    Document document = Document.builder()
            .s3Object(s3Object)
            .build();

    AnalyzeDocumentRequest request = AnalyzeDocumentRequest.builder()
            .document(document)
            .featureTypesWithStrings("TABLES", "FORMS")
            .build();

    return textractClient.analyzeDocument(request);
}

Process and Interpret Results

• The `AnalyzeDocumentResponse` object contains detailed information about the document's textual content, including detected form data and tables. Here's an example of processing the result:

public void processDocumentAnalysis(AnalyzeDocumentResponse response) {
    for (Block block : response.blocks()) {
        if (block.blockTypeAsString().equals("LINE")) {
            System.out.println("Detected Text: " + block.text());
        }
    }
}

Handle Exceptions and Errors

• Always ensure proper error handling. Amazon Textract might throw exceptions due to issues like unsupported document formats or access permissions.
• Use try-catch blocks to manage potential exceptions and log them to understand issues effectively.