test page for Grails projects
Key Points
- Grails scaffolding and GORM is IBM i DFU on steroids - any database, any Java runtime environment
- Where it fits, Grails is the fastest way to build Web apps or microservices using the right templates
- Grails generated apps provide a good starting point to understand how Web and REST microservices are built
- Grails generates Spring Boot applications and REST services
- Grails can build traditional MVC web apps or REST microservices using templates and generators
- Grails can generate simple front-ends for REST microservices - Angular, React, Web
- Grails profiles define which options an application or service will use
- Grails uses Groovy - a Java superset and a dynamic JVM language
- Grails v4x will use Groovy v3x when available in 2020
- Groovy v3x will support latest Java versions ( Lamba expressions, modules etc )
- I should look at running Grails REST service in Docker container similar to a Spring Boot REST service
- Tracking Grails releases in Github ( milestones etc ) https://github.com/grails/grails-core/releases
References
Test References
Find grails scripts, files and apps
from ~/
Groovy, Grails scripts
find ./ -iregex ".*setGr.*" 2>/dev/null -exec ls -l {} \;
Groovy work folders & files
find ./ -iregex ".*groovy" 2>/dev/null -exec ls -l {} \; | more
find ./ -ctime -150d -iregex ".*groovy" 2>/dev/null -exec ls -l {} \; | more
gdrv/_work/
use_case_template1.groovy
find ./ -ctime -120d -iregex ".*groovy" 2>/dev/null -exec ls -l {} \; | more
-rw-r--r--@ 1 jimmason staff 372220 Jul 22 09:09 .//learn/blearn-pc/gtest6.groovy
-rw-r--r-- 1 jimmason staff 1807 Dec 9 19:06 .//sfw/gdsl_base.groovy
-rw-r--r-- 1 jimmason staff 1944 Dec 13 18:52 .//sfw/use_case_template1.groovy
Grails apps list
find ./ -iregex ".*spring\/resources.groovy.*" 2>/dev/null -exec ls -l {} \; > ./temp/_grails_apps_list1.txt
gdrv files
gtwf1
gdrv//_work/learn/blearn-pc/gtwf1/grails-app/views/layouts/main.gsp.gz
gdrv//_work/jim-acer/blearn/gtwf1/grails-app/init/gtwf1/BootStrap.groovy
MAC files
grails4
jim-macbook:_dev jimmason$ ls -l ~/_dev/grails4
total 32
ptp test scripts
jim-macbook:~ jimmason$ ls -l _dev/_gdev
total 576
-rw-r--r-- 1 jimmason staff 2295 Aug 24 2015 JdbcTester1.groovy
-rw-r--r-- 1 jimmason staff 3727 Aug 31 2015 RunJdbcTester1.groovy
drwxr-xr-x 16 jimmason staff 512 Feb 19 2015 bookstore
drwxr-xr-x 3 jimmason staff 96 Aug 28 2015 com
drwxr-xr-x 15 jimmason staff 480 Feb 19 2015 gtest1
-rw-r--r-- 1 jimmason staff 282970 Jun 30 2016 gtest1a.groovy
drwxr-xr-x 15 jimmason staff 480 May 7 2016 test2
udemy grails course test
gdrv//_work/jim-acer/blearn/grails/peblock/grails-app/controllers/peblock/UrlMappings.groovy
Grails Install
Grails Setup
cat ./setGrails4.sh
#!/bin/bash
#
echo "----------- "
echo " setGrails4.sh - adds Grails4 home to path"
echo " "
#
# $GRAILS_HOME set
export MYSQL_JDBC=/Users/jimmason/_dev/lib/mysql-connector-java-5.1.34.jar
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home
export GRAILS_HOME=/Users/jimmason/_dev/grails4
export PATH=$PATH:$GRAILS_HOME:$GRAILS_HOME/bin
export CLASSPATH=$MYSQL_JDBC:$CLASSPATH
echo $PATH
Grails 3x requires JDK8 not JDK11
verify JDK is JDK8 NOT JDK11 ( the default system JDK I set )
grails --version && groovy --version
Project References
Key Concepts
Grails Training
grails v4x books - authors 4 days
http://docs.grails.org/latest/
grails mvc app using spring services - mode coding
https://www.baeldung.com/grails-mvc-application
https://www.google.com/search?client=firefox-b-1-d&q=grails+version+4+tutorials
Grails and Okta
https://developer.okta.com/blog/2018/04/19/okta-with-grails
Grails CRUD app with Okta
https://developer.okta.com/blog/2018/06/04/okta-with-grails-part2
Grails with Spring Security - default
https://www.slideshare.net/JesusPerezFranco/spring-security-5?from_action=save
Grails download & install
http://grails.org/download.html
Grails Application Forge
Manual Grails install
http://docs.grails.org/latest/guide/gettingStarted.html#downloadingAndInstalling
Set the GRAILS_HOME environment variable to the location where you extracted the zip
On Unix/Linux based systems this is typically a matter of adding something like the following
export GRAILS_HOME=/path/to/grailsto your profile
Then add the bin directory to your PATH variable:
On Unix/Linux based systems this can be done by adding
export PATH="$PATH:$GRAILS_HOME/bin"to your profile
Run version check
- grails version
Create shell script to set Grails version
setGrails41.sh
export GRAILS_HOME=`/Library/Grails/grails-4.1.0.M1`
export PATH=$GRAILS_HOME/bin:$PATH
groovy -version
Grails beta versions
Check for Grails versions released in Github here ( including milestones ) - https://github.com/grails/grails-core/releases
For a given release / milestone - check the Github issues to see what's important that's still open - https://github.com/grails/grails-core/issues
https://github.com/grails/grails-core/releases/tag/v4.1.0.M1
http://docs.grails.org/4.1.0.M1/guide/introduction.html#whatsNew
install from Zip file
ensure GRAILS_HOME, GROOVY_HOME, JAVA_HOME are set
ensure any CLASSPATH and path updates are correct
to validate, run:
grails -version
Grails docs on skwebteam
grails4-update-Slide_Deck_Introducing_Grails_4_Webinar.pdf
grails-181115-tutorial-guestbook-java-web-app-vogella.com-.pdf
gorm-basics-tutorial-relations-maps.pptx
grails-best-practices-web-profile-2016-MarProg_Grails_WP_Web.pdf
grails-web-mvc-tutorial-v4-mongodb-2019-vgood.pdf
grails-plugins.github.io-DB Reverse Engineering Plugin - Reference Documentation.pdf
Grails v4.0 Features
https://objectcomputing.com/products/grails/grails-roadmap
- Groovy 2.5
- GORM 7.0 (Hibernate 5.2 minimum, Java 8 baseline)
- Java 8 Baseline
- Java 11 Support
- Spring 5.1
- Spring Boot 2.1
- Micronaut Integration
Grails JAX-RS plugin documentation ( for Grails v3x )
http://budjb.github.io/grails-jaxrs/3.x/latest/guide/introduction.html
The jaxrs project is a set of Grails plugins that supports the development of RESTful web services based on the Java API for RESTful Web Services (JSR 311: JAX-RS).
It is targeted at developers who want to structure the web service layer of an application in a JSR 311 compatible way but still want to continue to use Grails' powerful features such as GORM, automated XML and JSON marshalling, Grails services, Grails filters and so on. This plugin is an alternative to Grails' built-in mechanism for implementing RESTful web services.
Features
- Makes the JSR 311 (JAX-RS) available to Grails applications for developing RESTful web services.
- New Grails artefact types, Resource and Provider, for JAX-RS classes.
- JAX-RS Resource classes under
grails-app/resourcesare auto-detected and can be modified at runtime. - JAX-RS Provider classes under
grails-app/providersare auto-detected and can be modified at runtime. - Extended Grails command line interface
- Create new resources and unit test templates via
grails create-resource <resource name>. - Generate ready-to-use resources from domain objects via
grails generate-resources <domain class name>. - Scaffolding
- Generate RESTful service interfaces for Grails domain objects.
- Content negotiation support for XML and JSON representations.
- Ability to use any Grails feature within JAX-RS resources and providers such as:
- GORM can be used for interacting with persistent domain objects.
- Grails filters for intercepting requests to JAX-RS resources. ( Deprecated )
- Grails services which can be auto-injected by name.
- Entity providers
- Domain object providers that convert between Grails domain objects and XML or JSON representations.
- Support classes for developing custom entity providers.
- Support for content negotiation based on the
Acceptrequest header. - Easy integration testing of JAX-RS resources and providers.
- Plugin users may choose between Jersey and Restlet as JAX-RS implementations by means of configuration.
- jaxrs applications can be deployed to Google App Engine (GAE).
Tutorial Migrate React Node.js app to Grails backend
https://guides.grails.org/grails-vs-nodejs/guide/index.html
To complete this guide, you will need the following:
Some time on your hands
A decent text editor or IDE
JDK 1.7 or greater installed with
JAVA_HOMEconfigured appropriately
To get started do the following:
Download and unzip the source
or
Clone the Git repository:
git clone https://github.com/grails-guides/grails-vs-nodejs.git
The Grails guides repositories contain two folders:
initialInitial project. Often a simple Grails app with some additional code to give you a head-start.completeA completed example. It is the result of working through the steps presented by the guide and applying those changes to theinitialfolder.
To complete the guide, go to the initial folder
cdintograils-guides/grails-vs-nodejs/initial
and follow the instructions in the next sections.
You can go right to the completed example if you The completed sample project for this article can be found at: https://github.com/grails-guides/grails-vs-nodejs/tree/master/complete create react profile appEvery Grails project begins with a single Choose the latest version of Grails (3.3.0 as of the time of writing) and select the
start client and server appsOnce you’ve downloaded your application, expand it into a directory of your choice, gradle wrapper can eliminate need to install Grails locallyThe gradle is similar to npm for build management It doesn’t provide the CLI that npm offers but it fulfills a similar purpose in dependency management and build-processing. When a Gradle command (or "task") is run, Gradle will first download all dependencies listed in the project’s What about the When running a Gradle “task” from the project root directory, anything after |
Where does bootRun come from? This Gradle task is inherited from the Spring Boot framework, upon which Grails is based. Of course create-react-app projects don’t have such a task by default. The React profile provides the client:bootRun task as a wrapper around the npm/yarn start script. This allows you to use advanced Gradle features like running both server and client in parallel mode with one command. For developers, running ../gradlew client:bootRun is the same as running npm start (or yarn start) in a stock create-react-app project, and in fact you can run the client app exactly that way if you have npm/yarn installed on your machine.
Once the gradlew commands have completed downloading dependencies and launching their respective apps, you should be able to browse to http://localhost:8080 to see the Grails backend application, and http://localhost:3000 to view the React app.
Data source setup - postgresql
GORM - Grails Object Relational Management
http://gorm.grails.org/6.1.x/hibernate/manual/#quickStartGuide
A domain class can be created with the create-domain-class command if you are using Grails, or if you are not using Grails you can just create the .groovy file manually:
grails create-domain-class helloworld.PersonThis will create a class at the location grails-app/domain/helloworld/Person.groovy such as the one below:
package helloworld
class Person {
}If you have the configured the dataSource.dbCreate property and set it to "update", "create" or "create-drop", GORM will automatically generate/modify the database tables for you. |
You can customize the class by adding properties:
class Person {
String name
Integer age
Date lastVisit
}Once you have a domain class try and manipulate it with console command in Grails by typing:
grails consoleThis loads an interactive GUI where you can run Groovy commands with access to the Spring ApplicationContext, GORM, etc.
Or if you are not using Grails here is a unit test template (using Spock) that can be run to test out the examples:
import spock.lang.*
import grails.gorm.annotation.Entity
import grails.transaction.Rollback
import org.grails.orm.hibernate.HibernateDatastore
import org.springframework.transaction.PlatformTransactionManager
class ExampleSpec extends Specification {
@Shared @AutoCleanup HibernateDatastore hibernateDatastore
@Shared PlatformTransactionManager transactionManager
void setupSpec() {
hibernateDatastore = new HibernateDatastore(Person)
transactionManager = hibernateDatastore.getTransactionManager()
}
@Rollback
void "test execute GORM standalone in a unit test"() {
// your logic here
}
}
@Entity
class Person {
...
}3.1. Basic CRUD
Try performing some basic CRUD (Create/Read/Update/Delete) operations.
3.1.1. Create
To create a domain class use Map constructor to set its properties and call the save() method:
def p = new Person(name: "Fred", age: 40, lastVisit: new Date())
p.save()The save() method will persist your class to the database using the underlying Hibernate ORM layer.
The save() method is defined by the GormEntity trait.
3.1.2. Read
GORM transparently adds an implicit id property to your domain class which you can use for retrieval:
def p = Person.get(1)
assert 1 == p.idThis uses the static get(id) method that expects a database identifier to read the Person object back from the database.
You can also load an object in a read-only state by using the read(id) method:
def p = Person.read(1)In this case the underlying Hibernate engine will not do any dirty checking and the object will not be persisted. Note that if you explicitly call the save() method then the object is placed back into a read-write state.
In addition, you can also load a proxy for an instance by using the load(id) method:
def p = Person.load(1)This incurs no database access until a method other than getId() is called. Hibernate then initializes the proxied instance, or throws an exception if no record is found for the specified id.
3.1.3. Update
To update an instance, change some properties and then call save() again:
def p = Person.get(1)
p.name = "Bob"
p.save()GORM DB Reverse Engineering Plugin - no longer supported
https://grails-plugins.github.io/grails-db-reverse-engineer/grails3v4/index.html
Burt Beckwith
Grails DB reverse engineering plugin does not work after Grails 3.1 - 2017
https://groups.google.com/forum/#!topic/grails-dev-discuss/CNmd8BRuf28
DB Reverse Tutorial
https://grails-plugins.github.io/grails-db-reverse-engineer/grails3v4/index.html#tutorial
last version of DB reverse engineering plugin
db-reverse-engineer-4.0.0-manual.pdf
early version of DB reverse engineering manual with books authors output classes
grails-db-reverse-engineering-plugin-v51-manual.pdf
Books and authors tables
create table author ( id bigint not auto_increment null, version bigint not null, name varchar(255) not null, email varchar(255) null, primary key (id)) ENGINE=InnoDB; create table book ( id bigint not auto_increment null, version bigint not null, title varchar(255) not null, type varchar(255), description varchar(2048), sold bigint null, primary key (id)) ENGINE=InnoDB; create table author_books ( author_id bigint not null, book_id bigint not null, primary key (author_id, book_id)) ENGINE=InnoDB; alter table author_books add index FKauthor_books_2_books (book_id), add constraint FKauthor_books_2_books foreign key (book_id) references book (id); alter table author_books add index FKauthor_books_2_authors (author_id), add constraint FKauthor_books_2_authors foreign key (author_id) references author(id);
Books and authors output classes from DB plugin
class Author {
String name
String email
String phone
static hasMany = [books: Book]
};
class Book {
String title
String publisher
BigDecimal price
String description
Integer quantitySold
static hasMany = [authors: Author]
static belongsTo = Author
};
class Author_Books {
String name
String email
static hasMany = [books: Book]
};
Final version of Books and authors output classes
Example of DB Reverse Engineering Output
Yes GORM. The reverse engineering for Grails is a little simpler because all that is needed are Domain classes and the framework handles all the hibernate mappings. So for example a DB table called Application would only need a single Domain class instead of a Domain, DAO and XML Mapping file. Here is an example with one-to-many and many-to-one relationships
class Application {
BigDecimal gpa
Date submitDate
String appliedFlag
String acceptedFlag
String deniedFlag
String managerNetid
Date timeStamp
AcademicYear academicYear
Quarter quarter
Student student
Set<ApplicationFile> applicationFiles = []
Set<ApplicationQa> applicationQas = []
Set<ApplicationAccepted> applicationAccepteds = []
Set<ApplicationDenied> applicationDenieds = []
static hasMany = [applicationAccepteds: ApplicationAccepted,
applicationDenieds: ApplicationDenied,
applicationFiles: ApplicationFile,
applicationQas: ApplicationQa]
static belongsTo = [AcademicYear, Quarter, Student]
static mapping = {
version false
quarter column: "quarter_code"
student column: "sid"
applicationAccepteds cascade: "save-update, delete-orphan"
applicationDenieds cascade: "save-update, delete-orphan"
applicationQas cascade: "save-update"
}
static constraints = {
submitDate nullable: true
appliedFlag maxSize: 1
acceptedFlag maxSize: 1
deniedFlag maxSize: 1
managerNetid nullable: true, maxSize: 36
}
}
There used to be a plugin for Grails that had this functionality and uses the hibernate-tools library but it stopped being maintained a while ago and the newer Grail releases are not compatible. I figured since MyEclipse uses the same hibernate-tools to generate Java code that maybe it would be possible to expand on that to generate Grails domain classes?
http://grails-plugins.github.io/grails-db-reverse-engineer/grails3v4/index.html
Depends on Hibernate Tools, Maven, Eclipse
Golang GORM
GORM - create tables from GOR
- Full-Featured ORM (almost)
- Associations (Has One, Has Many, Belongs To, Many To Many, Polymorphism)
- Callbacks (Before/After Create/Save/Update/Delete/Find)
- Preloading (eager loading)
- Transactions
- Composite Primary Key
- SQL Builder
- Auto Migrations
- Logger
- Extendable, write Plugins based on GORM callbacks
- Every feature comes with tests
install
go get -u github.com/jinzhu/gormsimple crud example
package main
import (
"github.com/jinzhu/gorm"
_ "github.com/jinzhu/gorm/dialects/sqlite"
)
type Product struct {
gorm.Model
Code string
Price uint
}
func main() {
db, err := gorm.Open("sqlite3", "test.db")
if err != nil {
panic("failed to connect database")
}
defer db.Close()
// Migrate the schema
db.AutoMigrate(&Product{})
// Create
db.Create(&Product{Code: "L1212", Price: 1000})
// Read
var product Product
db.First(&product, 1) // find product with id 1
db.First(&product, "code = ?", "L1212") // find product with code l1212
// Update - update product's price to 2000
db.Model(&product).Update("Price", 2000)
// Delete - delete product
db.Delete(&product)
}Generate Golang structs from SQL databases
https://github.com/smallnest/gen
could create a converter to generate GORM domain classes from Golang structs
or
directly create tool to build GORM domain classes from db tables using JDBC metadata and groovy
benefits of direct tool:
- no external dependencies
- could extend to NoSQL
- can pickup reference relations as "has" or "owns"
- can pickup primary key
Grails with Groovy 3x
4.1 M builds use Groovy 3
https://github.com/grails/grails-core/releases/tag/v4.1.0.M1
Potential Value Opportunities
Potential Challenges
Grails Java JDK compatibility
At some later point, ( 2020 or ? ), Grails will catch up with supported Java JDKs but not now.
The low-end default that will work is always JDK 8.
Groovy 2x still works with JDK 8 ( used by Grails 4x ) but not JDK 11 without a lot of custom work.
Grails 4 upgrade issues related to Java etc
https://github.com/grails/grails-core/wiki/Grails-4-Upgrade
Bug> Grails console can't open groovy file from menu or cli
bug> can't open a file from grails console using the file menu
workaround> use CTL + O
- open groovyconsole normally
- use CTL + O to open file selector window
- select a groovy file
- press Enter
- << file opens normally in groovy console
option 1> specify the file name on the cli cmd to open grails console
specify the file to open on the grails console command using relative url
grails console -f ./zfiles/gtest-2a1.groovy
<< no file shown
option 2> manually copy file contents to console window
open grails console
open the file from the File menu ( nothing shows )
open the same groovy file in another text editor
copy and paste the entire contents to the console window
add a comment line
File > save
check the saved file in the text editor to see the comment line exists
Grails 4.1 M++ – Groovy 3 and JDK11
Candidate Solutions
Simple Grails CRUD app on Grails 2x
User
EBC
Account
Device
Location
Energy
Steps after Grails setup
grails createApp gtcrud1
cd gtcrud1
grails console
- add the application folder to the grails path in the console
Step-by-step guide for Example
sample code block