Coding Assignment- week7codingassignment-main - Solved

Background 
The weekly exercises are designed to augment the video lessons. In the exercises, you will develop a menu-driven applica<on in Java. This applica<on will demonstrate how to perform CRUD (Create, Read, Update, and Delete) opera<ons on a MySQL database.

You will be working in a Project schema (database) that contains do-it-yourself (DIY) projects. A DIY project contains project details, materials, steps, and categories. Below is a diagram of the tables and rela<onships in the Project schema. Don't worry at this point if you don't understand what the diagram is telling you. This will become clear soon. For now, just know that there are five tables in the Project schema: project, material, step, category, and project_category. This is what you will build in the exercises.

  

There will be a final project in this (MySQL) part of the back-end course. These exercises will help prepare you for that.

Instruc:ons
 

 

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InstrucHons:  

1.  Follow the Exercises below to complete this assignment.  

•         In Eclipse, or an IDE of your choice, write the code that accomplishes the objec<ves listed below. Ensure that the code compiles and runs as directed.  

•         Create a new repository on GitHub for this week’s assignment and push your completed code to this dedicated repo, including your en<re Maven Project Directory (e.g., mysql-java) and any .sql files that you create.   

•         Include the func<onality into your Video when you see:    

•         Create a video showcasing your work:  

•         In this video: record and present your project verbally while showing the results of the working project.   Don’t forget to include the requested func<onality, indicated by:   

•         Easy way to Create a video:  Start a mee<ng in Zoom, share your screen, open Eclipse with the code and your Console window, start recording & record yourself describing and running the program showing the results.  

•         Your video should be a maximum of 5 minutes. 

•         Upload your video with a public link. 

•         Easy way to Create a Public Video Link:  Upload your video recording to YouTube with a public link. 

2.  In addi<on, please include the following in your Coding Assignment Document: 

•          The URL for this week’s GitHub repository. 

•          The URL of the public link of your video. 

3.  Save the Coding Assignment Document as a .pdf and do the following:  

•          Push the .pdf to the GitHub repo for this week.   



Objec:ves
In these exercises, you will:

•       Use MySQL Workbench to create a schema and user.

•       Use MySQL Workbench to assign schema privileges to a user.

•       Create a Maven project in Eclipse.

•       Add the MySQL driver as a dependency in pom.xml (Maven's Project Object Model – POM).

•       Separate project concerns by crea<ng packages.

•       Write Java code to connect to a MySQL database and schema.

Important
In the exercises below, you will see this icon:  . This means to make sure that you include this func<onality in your video showcase.

Exercises
In these exercises, you will use MySQL Workbench to create the project schema, as well as a user account. Then, you will create a Maven project. In the project you will write code to connect to the database schema that you created using MySQL Workbench.

Create the schema with MySQL Workbench
In this sec<on, you will use MySQL Workbench to create the projects schema, which MySQL tradi<onally and unfortunately also calls a database. You will also create a user with privileges only for that schema. In other words, the user account that you will create can only access the tables in the projects schema and no others. This is a good prac<ce in which a database account is only able to access the data it needs to perform its job. This step will help you accomplish that goal.

1.       Open and log into MySQL Workbench.

2.       Create a schema named "projects". Include your projects schema.  Your video should include something like this:

  

3.       Create a user named "projects" and assign a password.

4.       Add all privileges except "GRANT OPTION"  . Show this in your video:

  

Create a Maven Project
Maven is a tool that is used to control the building of a Java project. Eclipse comes bundled with an internal version of Maven and the two tools have a <ght integra<on. Maven has lots of features, but we will only be using it to add project dependencies. A project dependency is a library of code packaged as a Java Archive (JAR file). For our DIY project applica<on, there is only one dependency required: the MySQL driver.

To create a new Maven project:

1.       Click on the File menu in the top menu bar. Then select "New" / "Project". When the New Project wizard appears, expand "Maven". Select "New Maven Project" and click "Next".

2.       Check the box, "Create a simple project (skip archetype selec<on)". Click "Next".

3.       Enter the values in the table below into the fields and click "Finish".

Field
Value
Group ID
com.promineotech
Ar<fact ID
mysql-java
Version
0.0.1-SNAPSHOT
4.

Modify pom.xml
Maven knows how to build projects (and provide project dependencies) based on configura<on seings in an XML file named pom.xml. This file defines what Maven calls the Project Object Model (POM). The file is kept in the project root directory.

In this sec<on, you will add a property with the correct Java version. You will then add the MySQL driver as a project dependency. Then, you will add a plugin that will use the Java version property to set the correct Java version.

In this sec<on you will be working in pom.xml.  

1.       In this step you will add the Java version as a property in the Maven POM. You will set the value to 11 or 17 depending on the Java compiler version you have installed. To add the property:

a.       Create a <properties> sec<on below the version element and inside the closing </ project> tag. Add the closing </proper<es> tag below the opening tag.

b.       Inside the proper<es element, add the child element <java.version></ java.version>. Inside the java.version element, set the version to 11 or 17. It should look like this:

  

2.       In this step, you will add the MySQL driver as a dependency in the dependencies sec<on.

a.       Below the <properties> element, create a new element named <dependencies> with the closing tag </dependencies> below it.

b.       In a browser, navigate to hnps://mvnrepository.com/. Type "mysql" into the search box and press Enter.

c.       Find "MySQL Connector/J" (most likely the first result) and click the link "mysqlconnector-j". Click on the most recent version number link.

d.       You will see a page with informa<on about the dependency in a table followed by several tabs and a box with the dependency. Click in the box and the Maven dependency is copied to the clipboard.

 

e.       Paste the contents of the clipboard into the <dependencies> sec<on in pom.xml. The dependencies sec<on should look like this:

  

3.       In this step, you will need to add a sec<on to the POM that tells Eclipse which compiler version to use when compiling your project. This is done by adding a defini<on for the Maven compiler plugin.

a.       In a browser, navigate to the Maven compiler usage page: hnps://maven.apache.org/ plugins/maven-compiler-plugin/usage.html.

b.       Find the sec<on "Configuring Your Compiler Plugin". Copy the en<re <build> sec<on to the clipboard.

c.       Paste the clipboard contents into pom.xml below the <dependencies> sec<on. Replace the XML comment inside the configura<on element with a reference to the Java version defined in the proper<es sec<on. To add a property reference, surround it with $ {}. The sec<on should look like this:

  

At this point, if you are hopelessly lost, refer to the solu<ons sec<on below.

4.       Show all of your pom.xml.   

Set up the project packages
In this sec<on you will create the project structure by adding some packages. This will all be done in the Package Explorer panel in Eclipse.

1.    Create the following packages and subpackages under src/main/java.  Show the package structure in Package Explorer.   

a.       projects

b.       projects.dao

c.       projects.en<ty

d.       projects.excep<on

e.       projects.service  

Your screen shot should look like this:

  

Create an excep:on class
In this sec<on you will create an excep<on class that will be used in the mysql-java project. This is an unchecked excep<on that will be used throughout the applica<on. We do this because all of the excep<ons thrown by the Java Database Connec<vity (JDBC) API classes are checked SQLException objects. In coding the applica<on, you will turn the checked excep<ons into unchecked excep<ons to keep your code clean.

In this sec<on, you will create the class DbException in the projects.exception package.

1.    In the projects.exception package, create a class named "DbException". This class must extend RuntimeException. Override the following constructors from the superclass:

public DbException(String message) {} public DbException(Throwable cause) {} 

public DbException(String message, Throwable cause) {} 

Be sure to call the matching constructor in the superclass from each constructor in

DbException.  Show DbException class in your video.   

Create the JDBC connec:on class
In this sec<on, you will create a class that obtains a JDBC Connection object from the driver manager. When you call DriverManager.getConnection(), the driver manager looks up the MySQL driver and loads it. It then establishes a TCP connec<on between the applica<on and a MySQL server. If the connec<on cannot be made for some reason, the driver manager throws a checked SQLException. This is converted to an unchecked excep<on in a catch block.  

Follow these steps to create the JDBC Connection class.

1.       Create a class in the projects.dao package named DbConnection. In the class, create the following constants: HOST, PASSWORD, PORT, SCHEMA, and USER. Set the constants to the correct values. If you followed the instruc<ons above and created a user in MySQL Workbench, the constants should look like this:

  

2.       In the DbConnection class, create a method named getConnection(). It should be public and static and should return a java.sql.Connection object. In the getConnection() method:

a.       Create a String variable named uri that contains the MySQL connec<on URI.

b.       Call DriverManager to obtain a connec<on. Pass the connec<on string (URI) to DriverManager.getConnection().

c.       Surround the call to DriverManager.getConnection() with a try/catch block. The catch block should catch SQLException.

d.       Print a message to the console (System.out.println) if the connec<on is successful.

e.       Print an error message to the console if the connec<on fails. Throw a DbExcep<on if the connec<on fails.

f.        Show this en<re class.   

Create the main class
Every Java applica<on must have an entry point. This is a class with a main() method. In this sec<on, you will create a class with a main() method. From the main() method you will temporarily call DbConnection.getConnection() to test that you can obtain a connec<on to the MySQL server.

Follow these steps to create the applica<on entry point.

1.       Create a class in the projects package named ProjectsApp. The class must have a main() method.

2.       In the main() method, call the DbConnection.getConnection() method.

Run the Java applica<on. Show your console showing that the connec<on succeeded.   

Final touches
Typically, when you push a project to GitHub, you only want to push source code, not built class files or extra configura<on files maintained by a tool such as Eclipse. In a Maven project, all built classes are put in subdirectories off of the target directory. So, the target directory should not be pushed to GitHub.

Likewise, Eclipse maintains its project configura<on in a directory named ".settings". This directory should also not be pushed to GitHub.

To exclude files or directories from being pushed to GitHub, put the directory and file names into a file named .gitignore. This file must be in the project root directory. Simply put the paths of the files or directories on separate lines in .gitignore to tell git to ignore these files or directories.  

To ignore files, put the file name rela<ve to the project root. Separate directory names with slashes ("/"). To ignore directories, put the directory name on a separate line in .gitignore and add a slash ("/") on the end.

Follow these steps to instruct git to ignore the .seings directory and the target directory.

1.    In the root of the Eclipse project, create a file named ".gitignore". It should contain the following lines:

.settings/ target/ Solu:ons 

pom.xml
  

DbConnec:on.java
  

ProjectsApp.java
  

.gi:gnore
  

DbExcep:on.java