Forem: Fazeem Mohammed

Tricks to Increase your productivity

Fazeem Mohammed — Sun, 13 Nov 2022 09:24:19 +0000

Is anybody faced a scenario where they found it's efficient to automate the code generation so that eliminate monotonous work,
here a few scenarios I faced and how few tricks helped me to increase the productivity

Creating Database domain class from Schema, most of the time the database columns will be in snake case (eg: COLUMN_NAME), it will be error prone to create domain object of Table which have more than 20 columns manually. There are tools available in Hibernate and other ORM frame work to do it, but if don't want to use it please use the following snippet.

public static void printSnakeListToJavaVar(List<String> snakeList) {
    for (String columnName : snakeList) {
        columnName = columnName.trim();
        System.out.println("@Column(name=\"" + columnName + "\")");
        System.out.println("String " + snakeToJavaVar(columnName.toLowerCase()) + ";");
    }

}
public static String snakeToJavaVar(String str) {
    str=str.toLowerCase();
    // Run a loop till string
    return capitalizeFirstCharAfterDelimiter(str, "_");
}
private static String capitalizeFirstCharAfterDelimiter(String str, String deLimiter) {
    // string contains delimiter
    while (str.matches(".*" + deLimiter + ".*")) {

        str = str.replaceFirst(
                deLimiter + "[a-z0-9]",
                String.valueOf(
                        Character.toUpperCase(
                                str.charAt(
                                        str.indexOf(deLimiter) + 1))));
    }

    return str;
}

Schema from Domain object like in the first example there might situations a dev will be encountering to create a schema from domain object, the following code snippet will be helpful in this scenario

public static String camelToSnake(String str) {
    String result = "";
    char c = str.charAt(0);
    result = result + Character.toLowerCase(c);
    for (int i = 1; i < str.length(); i++) {

        char ch = str.charAt(i);
        if (Character.isUpperCase(ch)) {
            result = result + '_';
            result
                    = result
                    + Character.toLowerCase(ch);
        }else {
            result = result + ch;
        }
    }

    return result;
}

Delimited String to Upper Camel Case this is used when situation when dev has to Transform a String or set of String's which are Saved in ERP,DB etc. to a String presentable in UI

CaseConvertor.stringToUpperCamelIncludeDelimiter("12 DAYS"," ")
public static String stringToUpperCamelIncludeDelimiter(String str, String delimiter) {
    return Arrays.stream(str.toLowerCase().split(delimiter))
            .map(CaseConvertor::capitalize)
            .collect(Collectors.joining(delimiter));
}

public static String capitalize(String str) {
    if (str == null || str.length() <= 1) return str;
    return str.substring(0, 1).toUpperCase() + str.substring(1);
}

Want more tricks?
Please comment here

[Solution] Elastic Integration issue of Apollo server Graph QL program deployed as AWS lambda

Fazeem Mohammed — Mon, 07 Nov 2022 22:02:15 +0000

Hi,

Anybody facing Elastic Integration issue with Apollo server GraphQL program deployed as AWS lambda?
with error message
Unable to instrument Lambda handler \"graphql.graphqlHandler\" due to name conflict with \"graphql\", please choose a different Lambda handler name
here is the solution for it ->
https://github.com/trentm/example-apollo-lambda/tree/v1.0.0#notes--troubleshooting

Open source e-commerce project?

Fazeem Mohammed — Wed, 26 Oct 2022 17:44:25 +0000

I am looking for an e-commerce open source project, preferred Techstack is php/react, could you please comment here if you have any suggestions

Tools and Web Site helpful for Java folks

Fazeem Mohammed — Tue, 25 Oct 2022 10:09:18 +0000

Websites

json2csharp.com - this website helps to convert JSON string to Java Classes
yamllint - now a days Yml/Yaml is used across java projects as config tool, it's really hard to validate yml file structure as a single space can make yml corrupted, yaml lint helps to validate formatting of yml file

InteliJ Idea Plugins

GitLink - Gitlink Plugin Integrates most of the popular Git Based platform (GitLab, Bitbucket etc) to InteliJ Idea so Developers can open Web console directly from IDE
AWS toolkit - Rather than logging into aws console dev's can Trigger lambda, ecs tasks directly from IDE using this plugin

Tools

NotePad++ - NotePad++ Regulars expression Search/Replace functionality and Column Mode (Alt+select) helped me to improve my productivity significantly

Along with these tools using various shortcut's in InteliJ helped me to improve my productivity and speed of the development

more suggestion please ?

Enhanced Dynamo DB and Integration Test Using Dynamo Local

Fazeem Mohammed — Sun, 16 Oct 2022 23:03:35 +0000

AWS Released new Enhanced Dynamo Client Enhanced Dynamo Client which helps Java developers to easily Implement DAO Implementation without writing the mapping logic and AWS provides Downloadable DynamoDb which helps developers to do the Integration testing with Dynamo DB without connecting to the Cloud.

This post explains how to Implement a generic DynamoDBService Class using Enhanced Dynamo Client and Write Unit/Integration Test Cases using Downloadable DynamoDb

The full source code can be found under following repo

I have used following links and github repos to build this example

Prerequisite

Java > 11
Gradle > 5

Setting Enhanced Client in Gradle

To set up enhanced Client in Gradle following dependencies needs to be added

  implementation 'com.amazonaws:aws-java-sdk-dynamodb:1.11.434'
  implementation 'software.amazon.awssdk:dynamodb:2.17.28'
   implementation 'software.amazon.awssdk:dynamodb-enhanced:2.17.28'

Setting up DynamoDb Local

Aws documentation provides steps to setting up maven build but Gradle setting up is not provided by AWS and this library is not available central maven repo, so users needs to set up aws maven repo for setting DynamoDb Local

repositories {
    maven {
        name
         url "https://s3-us-west-2.amazonaws.com/dynamodb-local/release"
    }
}

following dependency will add DynamoDbLocal to the gradle project

testImplementation group: 'com.amazonaws', name: 'DynamoDBLocal', version: '1.11.119'

you can find more info about the set up in https://github.com/redskap/aws-dynamodb-java-example-local-testing/blob/master/README.md . As a part of test setup copy AwsDynamoDbLocalTestUtils and call AwsDynamoDbLocalTestUtils#initSqLite() during setup function of JUnit Test class

DynamoDb Domain POJO

This class is POJO representation of Dynamo DB schema, I have used lombok to avoid boiler plating of Getter and Setter methods, @DynamoDbBean represents dynamo db structure and @DynamoDbPartitionKey represents primary key id

 @Data
@DynamoDbBean
public class Student {
    private String studentId;
    private String studentName;
    private String department;
    @DynamoDbPartitionKey
    @DynamoDbAttribute("studentId")
    public String getStudentId() {
        return studentId;
    }
}

DynamoDb Service Implementation

This class has full DAO implementation

CreateTable
Insert/Update Item based on partitions key
Get Item by Id

DynamoDBService.java

Setting Up JUnit Test class

During the startup JUnit will spin up a local dynamo DB instance and following code shows how to establish DynamoClient connectivity to local instance

private static final String TABLE\_NAME = "Student";
private static  DynamoDBProxyServer server;
private static final String port = "8000";
private static final String uri = "http://localhost:"+port;

 @BeforeEach
    public void setUpTest() throws Exception {

        AwsDynamoDbLocalTestUtils.initSqLite();

        server = ServerRunner.createServerFromCommandLineArgs(
                new String\[\]{"-inMemory", "-port", port});
        server.start();
        client=DynamoDbClient.builder()
                .endpointOverride(URI.create(uri))
                .region(Region.AF\_SOUTH\_1)                .credentialsProvider(StaticCredentialsProvider.create(
                        AwsBasicCredentials.create("fakeMyKeyId","fakeSecretAccessKey")))
                .build();
}