Tag: example

Aws Lambda Java Post example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP POST request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the post data
            JsonNode postData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String name = postData.get("name").asText();
            Response responseBody = new Response("Hello, " + name);

            return ApiGatewayResponse.builder()
                    .setStatusCode(200)
                    .setObjectBody(responseBody)
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        } catch (IOException e) {
            logger.log(e.getMessage());
            return ApiGatewayResponse.builder()
                    .setStatusCode(500)
                    .setObjectBody("Error while parsing input: " + e.getMessage())
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        }
    }
}

In this example, the class MyLambdaFunction implements the RequestHandler interface, which is provided by the AWS Lambda Java SDK. The class takes in two parameters: Map and Context, which represent the input to the function and the runtime context of the function, respectively.

The function uses the ObjectMapper class to parse the request body as a JSON object and extract the name property. It then creates an instance of the Response class with the message “Hello, ” + name and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming POST request and route it to your Lambda function.

It’s important to note that this is just a basic example and depending on your use case you might need to handle authentication, validation, error handling and other requirements.
You might also need to import the classes used on this example like com.amazonaws.services.lambda.runtime.Context, com.amazonaws.services.lambda.runtime.LambdaLogger, com.amazonaws.services.lambda.runtime.RequestHandler and other.

Aws Lambda Java Get Header example code

Here is an example of an AWS Lambda function written in Java that retrieves and parses headers from an HTTP request:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve headers from input
        Map headers = (Map)input.get("headers");

        // Parse specific header
        String myHeader = headers.get("my-header");

        // Do something with the header value
        Response responseBody = new Response("Hello, " + myHeader);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the headers from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of a specific header, in this case “my-header”, and save it to a variable. Then the function creates an instance of the Response class with the message “Hello, ” + myHeader and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming GET request and route it to your Lambda function.

It’s important to note that this is just a basic example and depending on your use case you might need to handle authentication, validation, error handling and other requirements.
You might also need to import the classes used on this example like com.amazonaws.services.lambda.runtime.Context, com.amazonaws.services.lambda.runtime.LambdaLogger, com.amazonaws.services.lambda.runtime.RequestHandler and other.

Aws Lambda Java get Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP GET request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve query string parameters
        Map queryParams = (Map)input.get("queryStringParameters");

        // Retrieve name
        String name = queryParams.get("name");

        // Do something with the query string parameters
        Response responseBody = new Response("Hello, " + name);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the query string parameters from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of the name parameter and saves it to a variable. Then the function creates an instance of the Response class with the message “Hello, ” + name and returns it as the response to the request.

Aws Lambda Java Put Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP PUT request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the put data
            JsonNode putData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String name = putData.get("name").asText();
            Response responseBody = new Response("Hello, " + name);

            return ApiGatewayResponse.builder()
                    .setStatusCode(200)
                    .setObjectBody(responseBody)
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        } catch (IOException e) {
            logger.log(e.getMessage());
            return ApiGatewayResponse.builder()
                    .setStatusCode(500)
                    .setObjectBody("Error while parsing input: " + e.getMessage())
                    .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                    .build();
        }
    }
}

In this example, the class MyLambdaFunction implements the RequestHandler interface, which is provided by the AWS Lambda

Aws Lambda Java Delete Example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP DELETE request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();

        // Retrieve query string parameters
        Map queryParams = (Map)input.get("queryStringParameters");

        // Retrieve id
        String id = queryParams.get("id");

        // Delete the item
        deleteItem(id);

        // Create a response
        Response responseBody = new Response("Successfully deleted item with id: " + id);

        return ApiGatewayResponse.builder()
                .setStatusCode(200)
                .setObjectBody(responseBody)
                .setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
                .build();
    }
}

This example retrieves the query string parameters from the input object, which is passed as the first argument to the Lambda function. It then uses the get() method to retrieve the value of the id parameter and saves it to a variable. It then calls the deleteItem(id) function to delete the item from the database. Finally, it creates an instance of the Response class with the message “Successfully deleted item with id: ” + id and returns it as the response to the request.

You would need to create a new Lambda function in the AWS Lambda console and then upload the JAR file containing this code. After that, you would need to configure an API Gateway trigger to handle the incoming DELETE request and route it to your Lambda function.

Aws Lambda Java Patch example code

Here is an example of an AWS Lambda function written in Java that handles an HTTP PATCH request and returns a JSON response:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Map;

public class MyLambdaFunction implements RequestHandler, ApiGatewayResponse> {

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public ApiGatewayResponse handleRequest(Map input, Context context) {
        LambdaLogger logger = context.getLogger();
        try {
            // parse the patch data
            JsonNode patchData = objectMapper.readTree((String) input.get("body"));

            // do something with the data
            String id = patchData.get("id").asText();
            String newValue = patchData.get("new_value").asText();
            updateItem(id, newValue);

            Response responseBody = new Response("Successfully updated