How to use the command 'jhipster' (with examples)

JHipster is an application generator that simplifies the development of modern web applications and microservices architecture. It offers a robust environment for creating monolithic or distributed applications, equipping developers with both server-side (Java) and client-side (JavaScript) technologies. The tool is widely appreciated for automating various parts of the development process, resulting in efficient initialization, scaffolding, and deployment.

Use case 1: Generate a simple full-stack project (monolithic or microservices)

Code:

jhipster

Motivation: This command is the quintessential starting point for developers who wish to build a full-stack application using JHipster. By simply executing jhipster, users are led through an interactive process that guides them to create a complete application solution, tailored to either a monolithic or microservices architecture. This functionality is valued for its simplicity and ability to quickly bootstrap extensive projects with minimal setup, allowing developers to focus on business logic rather than infrastructure.

Explanation: The command jhipster with no additional arguments initiates the full experience of application generation. It invokes an interactive session that prompts the user for numerous options, including the choice between monolithic or microservices architecture and additional configurations such as the database or authentication mechanisms.

Example Output: Upon execution, the console will prompt for inputs and display the creation of application files, setup logs, and installation of dependencies. The resulting directory structure will contain a ready-to-run full-stack application.

Use case 2: Generate a simple frontend project

Code:

jhipster --skip-server

Motivation: Often, developers are tasked with crafting user interfaces while leveraging pre-existing backend services. In these instances, generating just the frontend code allows developers to focus on the client layer, without the overhead of server-side components. It becomes particularly useful in teams split between front-end and back-end roles, or when integrating with REST services not developed with JHipster.

Explanation: The argument --skip-server signals JHipster to bypass the generation of the server-side components. As a result, only the Angular, React, or Vue.js-based client-side code is scaffolded, depending on the developer’s preference.

Example Output: The command generates a structured directory containing HTML, CSS, JavaScript, and related frontend assets, but omits any Java backend components. The build scripts for the front-end framework specified during the interactive process are also included.

Use case 3: Generate a simple backend project

Code:

jhipster --skip-client

Motivation: In scenarios where the emphasis is on creating robust API services that other applications or clients will consume, generating only the backend code can be most beneficial. This allows a team to focus on optimizing data handling, security, and business processes independently from UI concerns.

Explanation: Using the --skip-client argument instructs JHipster to generate only server-side components, such as the Spring Boot applications in Java. No client-side code is generated, directing focus to API and service development.

Example Output: Executing this command yields a backend service application, complete with controllers, services, and repositories tailored to a specified database. There are no HTML/CSS/JavaScript assets involved.

Use case 4: Apply latest JHipster updates to the project

Code:

jhipster upgrade

Motivation: Keeping software dependencies and configurations updated is crucial for maintaining security and performance standards. The upgrade command automates the process of bringing an existing JHipster project up to date with the latest stable releases, sparing developers from the complexities of manual merging.

Explanation: The command jhipster upgrade searches for newer stable versions of the JHipster generator, applies them locally, and updates any altered configurations or dependencies in the project.

Example Output: On execution, the console shows the progress of the upgrade, including fetching new versions, updating project files, and resolving any dependency conflicts. A summary of updated components is displayed post completion.

Use case 5: Add a new entity to a generated project

Code:

jhipster entity entity_name

Motivation: Entities in JHipster represent domain objects that are crucial to application logic. Adding an entity is commonplace in application development, as projects evolve to meet new business requirements. This command makes it easy to manage the full stack of necessary changes from database schema updates to API endpoints and front-end interfaces.

Explanation: The entity command followed by the desired entity name triggers an interactive process where fields, relationships, and constraints for the new entity can be specified. JHipster efficiently scaffolds all necessary layers corresponding to the entity across the application.

Example Output: The process results in updated database schema files, new API endpoints, and front-end interfaces, automatically aligned with the new entity and ready for integration into the app workflow.

Use case 6: Import a JDL file to configure your application

Code:

jhipster import-jdl first_file.jh second_file.jh ... n_file.jh

Motivation: JHipster Domain Language (JDL) is a syntax crafted to define and document the entities and relationships within an application. Importing a JDL file allows for rapid configuration of complex entities, themes, or actions across an application, ideal for rapid prototyping and clear visual domain mapping.

Explanation: The import-jdl command accepts one or more .jh files, each containing JDL code, as inputs. It parses these files and translates the JDL definitions into application configurations, involving entities, relationships, deployments, or even complete app setups.

Example Output: Execution of this command processes the JDL file(s) and generates the respective entities and configurations as defined, visibly updating project directories with new code and documentation.

Use case 7: Generate a CI/CD pipeline for your application

Code:

jhipster ci-cd

Motivation: Continuous Integration and Continuous Deployment (CI/CD) pipelines automate testing, building, and deployment of code, enhancing reliability and speed of software releases. JHipster simplifies setting up these pipelines to match industry standards for DevOps practices, significantly aiding agile processes.

Explanation: The ci-cd command engages configuration scripts and templates to generate necessary files for setting up different CI/CD environments (e.g., Jenkins, GitLab CI, Travis CI), enabling automated deployment routines and integration testing for the project.

Example Output: The generation process outputs a set of files tailored to the chosen CI/CD tools, complete with configuration scripts that can be directly utilized within the CI/CD platform.

Use case 8: Generate a Kubernetes configuration for your application

Code:

jhipster kubernetes

Motivation: As applications scale, Kubernetes facilitates efficient container orchestration across clusters. JHipster supports this need by automating Kubernetes configuration generation, aiding developers to deploy and manage their applications seamlessly in a containerized ecosystem.

Explanation: The kubernetes command crafts the Docker and Kubernetes YAML configuration files required to containerize the application components and deploy them onto a Kubernetes cluster.

Example Output: This command generates a suite of configuration and descriptor files that define Kubernetes pods, services, persistent volumes, and more, making it easy to initiate deployments using Kubernetes’s orchestration abilities.

Conclusion:

With its range of functionalities and ease of use, JHipster acts as a powerful enabler for the rapid development and deployment of modern applications. Whether forming the foundation of a new project or scaling existing solutions, its commands cover a spectrum of development needs, from full-stack generation to tailored CI/CD integration and container orchestration.