team02 : Team Project: Spring Boot Backend, part 2 (authenticated CRUD)

Big Picture: what is team02 all about?

From a high-level standpoint, you’ll be doing these things:

Set up Tasks:

• Setting up a Repo with qa and prod deployments on Heroku
• Configuring the documentation repos
• Configuring Codecov

Coding Tasks:

• Adding six database tables
• Setting up CRUD operations for all three of those tables
• Adding backend test coverage for all of that

For this assignment, we are still dealing directly with the backend via Swagger.

In the next assignment, we’ll start looking how how to build a proper front end for the types of things we did in both team01 and team02.

More details on team02

In this team project, our starter code has a frontend and backend, however we are still focusing only on the backend part. The front end provides only a place for us to login with our Google account.

We are focusing on learning these new Spring Boot backend concepts:

• Creating SQL database tables using @Entity and @Repository
• Using the Lombok annotations: @Data, @NoArgsConstructor, @Builder, etc.
• Implementing controller routes for CRUD operations (Created, Read, Update, Destroy)
• Writing unit tests for controller CRUD operations, including the use of:
  • Spring MockMvc
  • Mockito methods for creating mocks of repositories and services (when, `verify)
  • the idea of “dependency injection”

In addition, we’ll practice further with a few concepts that we touched on in jpa03, but may not have fully fleshed out:

• Set up of the documentation repos, the -docs and -docs-qa repos
• Working with feature branches, issues, a Kanban board, pull requests, and GitHub actions scripts
• Working with code coverage and mutation testing

The starting code

Your starter code provides Spring Boot code with the ability to do CRUD operations on two database tables:

• UCSBDates
• UCSBDiningCommons

These tables are set up to match the data that is available through two public APIs that are provided by UCSB and documented at https://developer.ucsb.edu.

The UCSBDates tables has three columns, and is intended to store data like that shown here:

The UCSBDiningCommons table has six columns, and is intended to store data like that shown here:

Your task: add CRUD for additional database tables

You’ll be adding CRUD operations for six additional database tables; one per team member:

Here are the six tables you’ll be adding (one per person).

On the Kanban board, you’ll find five issues for each of these tables:

• Add database table (the @Entity and @Repository classes, no test classes)
• Add GET endpoint to list all database records, and a POST endpoint to create new database records, plus tests (this, and all of the rest, are done in the Controller and Controller test classes)
• Add GET endpoint to get a single database row by its id. (plus tests)
• Add PUT endpoint to update a single database row by its id. (plus tests)
• Add DELETE endpoint to delete a single database row by its id. (plus tests)

You should choose one of these database tables, and then assign yourself the five issues that pertain to that database table.

As you look over these, note that some of them use an autogenerated Long as the @Id field, while others use a different field already in the data. That may not make any sense to you right now, but there is an explanation immediately following the list of database tables.
We’ll also go over this in lecture.

(1) UCSB Dining Commons Menu

(2) UCSB Organization

(3) Recommendation Request

(4) Menu Item Review

(5) Help Request

(6) Articles

Two types of id values

Every database table has a primary key marked in a Spring Boot @Entity class with the annotation @Id.

This value must be unique in the database table; no two rows can have the same primary key.

There are two strategies for dealing with this requirement:

1. Autogenerated ids, which start at 1 and then increment automatically. The UCSBDate entity in the starter code is an example. The code looks liek this:

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private long id;
   

   As an aside: you may wonder what happens when we run out of numbers. Since these id numbers are typically stored in a 64-bit Java Long, the maximum number is: 9,223,372,036,854,775,807L.

   • If you stored 1 Million records per second, 24 hours a day, 7 days a week, it would take you 292 thousand years to cycle through this many id numbers.
   • That’s also over 18,000 records for every square meter on the face of the planet earth. Not sure what database table needs that many records.

2. Using a value already in the data that is inherently unique. For example, we might use perm number as an id field for a table of students.

   The UCSBDiningCommons entity in the sample code shows an example, where the code field is guaranteed to be unique; no two dining commons will have the same code value:

   @Id
   private String code;
   

It is important to understand that when you set up an @Repository class, the types that you pass to CRUDRepository as shown below must match the type of the @Entity and the type of the @Id field, as in these examples:

1. UCSBDateRepository uses CrudRepository<UCSBDate, Long> because the @Id field of UCSBDate is a Long:

    @Repository
    public interface UCSBDateRepository extends CrudRepository<UCSBDate, Long> {
    ...
   

2. UCSBDiningCommonsRepository uses CrudRepository<UCSBDate, String> because the @Id field of UCSBDiningCommons is a String:

    @Repository
    public interface UCSBDiningCommonsRepository extends CrudRepository<UCSBDiningCommons, String> {
    ...
   

As you look over your database table description above, take note of which of these applies to you.

What you’ll do: Process

From a process standpoint, this project works the same as team01:

Here’s how that will play out in detail:

1. To start, each of you should clone your team’s team02-teamname repo, which should already have a Kanban board set up for it.
2. On the team’s Kanban board, there should be three types of issues, marked with Tags
   • Set up tasks: done at the start of the project (marked with the label SETUP)
   • Regular coding tasks: done in the middle of the project
   • Clean up tasks: done at the end of the project (marked with the label CLEANUP) Notice the tags for each of these types of issues.
3. First, divide up the set up tasks among the members of the team, and assign each of those to a team member. Leave them in the “to do” column, though, until you actually start working on the issue.

4. Then, divide up the six database tables among the team members. I suggest that you do this on your team slack channel in a single post, and then “pin” that post to your channel. That post might look something like this:

   Adam:  Articles
   Brianna: Menu Item Review
   Chris:  Help Request
   Danny: Recommendation Request
   Erin: UCSB Organization
   Fay: UCSB Dining Commons Menu
   

5. Now look on the Kanban board. You should find that there are five issues on the Kanban board for your specific database table:

   • create_database_table
   • add_list_all_and_post_endpoints
   • add get for single item
   • add put for single item
   • add delete for single item

   You should find all of the stories for your database item, and assign them to yourself; but drag only one into the In Progress column (and if you are already assigned to one of the set up tasks, don’t even drag that one yet!

   Typically, you should be assigned to only one item at a time in the In Progress column. The exception is if you drag an item to In Progress, make some progress on it, and then need to stop working on it for a while because you are blocked, or something else urgently needs your attention. But that should be the exception, not the normal way of doing things.

6. Now work on your issues as you did in team01; dragging them to “In Review” once they are ready for code review, and to “Done” when they are merged.
7. Near the end of the project there are a few “clean up tasks” for your team. Those are marked as such on the Kanban board. One of the last of those is to submit on Gauchospace for your team to note that your team is ready for the work to be graded.

Getting started

To get started:

• One member of your team should clone your teams empty team02 repo
• Add the STARTER-team02 repo as a remote called starter
• Do git checkout -b main, git pull starter main, git push origin main

Implement CRUD operations for a database table

To add an SQL database table in Spring Boot, you typically add two files:

• A Java class that is annotated with @Entity; each instance of this class represents a single row in the database table
• A Java class that is annotated with @Repository; each instance of this class represents a database table.

There is more information in the issues on the Kanban board to guide you through the rest of the process.

More Hints

We may add more hints about working with the team02 code as we discover what problems studnets run into.

In the meantime, use the #help-team02 channel to ask questions.

A note about open source

Note that this assignment is open source.

The repos are public on purpose.

• You are encouraged to consult with one another within and across teams where it helps your learning.
• That does not mean that you can cheat by just copying code from another team.
• You are not permitted to just look at another team’s code, even though you “can”.
• It does mean that you should try to solve the problems as best you can, but you may consult with members of other teams as you work. In that context, you may look at other team’s code.

This isn’t hard. You all know when you are are looking at other team’s work to try to learn, versus when you are just looking at it as a shortcut to learning.

I’m trusting you to do the right thing. This is practice for when, later on, you are all working on different assignments.

Understanding how to create the @Entity class

For example of @Entity classes, consult these files in the starter code:

• UCSBDate.java
• UCSBDiningCommons.java

You’ll see that these files have a particular structure, with these annotations:

UCSBDate.java:

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Entity(name = "ucsbdates")
public class UCSBDate {

UCSBDiningCommons.java:

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Entity(name = "ucsbdiningcommons")
public class UCSBDiningCommons {

What do these annotations do?

• @Data is an annotation from a package called Lombok. Lombok automatically generates code for some of the tedious things that can be automated: getters, setters, toString, hashCode and equals. It also implements a constructor for all “required arguments”, though that one is not always very convenient to use if we have lots of fields.
• @AllArgsConstructor and @NoArgsConstructor are additional Lombok annotations that define additional constructors for us. The @NoArgsConstructor is particularly important, since it’s a requirement of many pieces of Java Software that classes implement a no-args constructor (it’s part of what it means to be a Java Bean.)
• @Builder create a class and some methods that make it easy to build objects with a syntax like this:

  UCSBDiningCommons commons = UCSBDiningCommons.builder()
        .name("Carrillo")
        .code("carrillo")
        .hasSackMeal(false)
        .hasTakeOutMeal(false)
        .hasDiningCam(true)
        .latitude(34.409953)
        .longitude(-119.85277)
        .build();
  

• @Entity(name = "ucsbdiningcommons") is the annotation that says this will be a row in a database table; the parameter sets the name of the table.

With these annotations in place, it’s a simple matter of defining private fields for each of the columns in the database table.

Details: @Repository class

For the repository class, see the examples:

• UCSBDateRepository
• UCSBDiningCommonsRepository

Note that these are both interface files and not classes.

Normally, if you create an interface, you also need to create a class that implements that interface.

However, Spring Boot will automatically generate the code for you.

In addition, if you need certain kinds of queries, you can specify methods in your interface to implement those queries.

The rules for translating method naming conventions into generated code are complicated: we will not go over all of them in lecture, and you are not expected to memorize or learn them all, and you probably won’t need that for this assignment (though you may need to know it later in the course.)

In any case, if/when you do need to understand that, here is some documentation is here to help get you started: https://docs.spring.io/spring-data/jdbc/docs/current/reference/html/#jdbc.query-methods

Details: Controller methods and tests

The examples for the Controller Methods are tests are in these files:

• Controllers:
  • UCSBDatesController.java
  • UCSBDiningCommonsController.java
• Controller Tests:
  • UCSBDatesControllerTests.java
  • UCSBDiningCommonsControllerTests.java

You should be able to find the code you need for each of the methods, and use it as a model to create the code for your database table.

If you need additional guidance, ask on the #help-team02 channel, and we’ll try to steer you in the right direction.

When you are done

When all branches are merged to main, all tasks on Kanban board in the done column, please submit on Gauchospace