To push codebase from IntelliJ IDEA (or any JetBrains products) on a local machine to a VM instance in Google Cloud Platform.

To run the codebase remotely.

WHY DO THIS

You want to leverage all the power of a modern IDE on your 4K screen.

You do not want to use remote desktop tools such as VNC or NoMachine due to performance and screen lag problems.

Your team members make fun of your VIM skills.

SOLUTION

Configuring VM Port Forwarding

Log into GCP.

gcloud auth login

Perform port forwarding over SSH using your running VM.

# SYNTAX
gcloud compute ssh VM_NAME \
    --project PROJECT_ID \
    --zone ZONE \
    -- -NL LOCAL_PORT:localhost:REMOTE_PORT

# EXAMPLE
gcloud compute ssh shitty_vm \
    --project shitty_project \
    --zone us-central1-b \
    -- -NL 8888:localhost:22

Note: If you choose to listen to local port 22, you will most likely to get this error because your local SSH server may already be using it:

bind: Address already in use
channel_setup_fwd_listener: cannot listen to port: 22
Could not request local forwarding.

If this is your first SSH into your VM, you will be prompted to create the SSH key pair. In this case, keep pressing the “Enter” key until it is created.

WARNING: The private SSH key file for gcloud does not exist.
WARNING: The public SSH key file for gcloud does not exist.
WARNING: You do not have an SSH key for gcloud.
WARNING: SSH keygen will be executed to generate a key.
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/shitty_user/.ssh/google_compute_engine.
Your public key has been saved in /Users/shitty_user/.ssh/google_compute_engine.pub.
The key fingerprint is:
SHA256:gmwGL9bfJLi/FYnebZLL0vVBYoZ3XeT/ivSSFCmiRT8 shitty_user@shitty_machine
The key's randomart image is:
+---[RSA 3072]----+
|               ..|
|        .      ..|
|  .    . o   o ..|
|   = o .+.E = . .|
|  o O +oS= * .  .|
| . + +.* +. o   .|
|    . o.*.oo.o  .|
|     ..o.+ .+o . |
|      ooo   ..o  |
+----[SHA256]-----+
External IP address was not found; defaulting to using IAP tunneling.
Writing 3 keys to /Users/shitty_user/.ssh/google_compute_known_hosts

Upon a successful port forwarding, the command will hang with the following text:

External IP address was not found; defaulting to using IAP tunneling.
Existing host keys found in /Users/shitty_user/.ssh/google_compute_known_hosts

That is an expected behavior because the SSH tunnel is now established between your local machine and the VM.

Configuring IntelliJ IDEA

In IntelliJ IDEA, select Tools > Deployment > Browser Remote Host

Under Remote Host panel, select … button.

Under Add Server dialog:

• Name: <A Memorable Name… ex: shitty_server>
• Type: SFTP

Click OK button.

Under Deployment dialog, select … button on SSH Configurations.

Under SSH Configurations dialog:

• Host: localhost
• Port: 8888 (or the local port you specified)
• User name: <Your VM’s user name>
• Authentication type: Key pair
• Private key file: /<PATH>/.ssh/google_compute_engine

Click on Test Connection button and ensure it is successful.

Click OK button.

Under Deployment dialog, select Mappings tab.

Under Mappings tab, click on the folder icon and specify a location to deploy the codebase to.

Click OK button.

Under Remote Host panel, you can now browse and access the files in your VM remotely.

Pushing Codebase from IntelliJ IDEA to VM

To deploy codebase to the VM, right click on the directory, select Deployment > Upload to [VM_NAME].

The codebase should be copied to the location you specified.

Tips: If you makes changes in both your local machine and VM, select Deployment > Sync with Deployed to [VM_NAME]. This allows you to synchronize the changes on both sides.

Running Codebase Remotely

To run the codebase remotely, select Tools > Start SSH Session.

Select the configured host.

Run the codebase.

The post GCP: Pushing Codebase from IntelliJ IDEA to VM Instance appeared first on My Shitty Code.

Because the rarely changed classes (ex: 3rd party JARs) are separated out into a different classloader from the app’s actively developed classes’ classloader, it allows Spring Boot to quickly restart the app compared to “cold start”.

DEPENDENCY

First, add the following dependency:-

<dependency>
	<groupid>org.springframework.boot</groupid>
	<artifactid>spring-boot-devtools</artifactid>
	<scope>runtime</scope>
</dependency>

CONFIGURING INTELLIJ IDEA

In IntelliJ IDEA:-

• Click SHIFT twice to bring up the “Search History” dialog.
• Select “Actions” tab.
• Type “Registry” in the search box.
• Select “Registry…”.

In the “Registry” dialog:-

• Find “compiler.automake.allow.when.app.running” key.
• Check the checkbox.
• Close the dialog.

In IntelliJ IDEA “Preferences” dialog:-

• Go to “Build, Execution, Deployment” » “Compiler”.
• Check “Build project automatically”.
• Close the dialog.

Finally, instead of running Maven goals to run the Spring Boot app, select the Application class (annotated with @SpringBootApplication) and run it from IntelliJ IDEA.

Anytime the app’s class files have changed, IntelliJ IDEA will compile the app, which will then trigger Spring Boot Dev Tools to restart the app.

The post Spring Boot: Restarting App using Dev Tools with IntelliJ IDEA appeared first on My Shitty Code.

When creating or checking out a project for the first time in IntelliJ IDEA, we may need to reconfigure the project settings. My biggest pain is IntelliJ IDEA will always use the wrong Maven version when I check out the project from the source control.

SOLUTION

The good news is there is a way to set up default project settings in IntelliJ IDEA.

In the Welcome dialog, select Configure -> Project Defaults.

From here, we can create all the default project settings, such as JDK version, Maven version, code style formatter and so on.

The post IntelliJ IDEA: Configuring Default Project Settings appeared first on My Shitty Code.

Let’s assume we want to create the default equals(), hashCode() and toString() with the following bean:-

public final class Person {
    private final String name;
    private final Collection<car> cars;

    public Person(final String name, final Collection<car> cars) {
        this.name = name;
        this.cars = cars;
    }

    public String getName() {
        return name;
    }

    public Collection<car> getCars() {
        return cars;
    }
}

Most IDEs, including older version of IntelliJ, have code generation features that would create something similar to this:-

public final class Person {
    ...

    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        final Person person = (Person) o;

        if (name != null ? !name.equals(person.name) : person.name != null) {
            return false;
        }
        return !(cars != null ? !cars.equals(person.cars) : person.cars != null);
    }

    @Override
    public int hashCode() {
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + (cars != null ? cars.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "Person{" +
               "name='" + name + '\'' +
               ", cars=" + cars +
               '}';
    }
}

While it works, the generated code is usually crazy horrendous.

SOLUTION

With IntelliJ 14.x, it allows us to select templates from several proven libraries.

To generate equals() and hashCode(), select equals() and hashCode() option from the Generate pop-up dialog:-

There are several templates to choose from:-

Here’s an example of equals() and hashCode() using Guava and getter methods:-

public final class Person {
    ...

    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        final Person person = (Person) o;
        return Objects.equal(getName(), person.getName()) &&
               Objects.equal(getCars(), person.getCars());
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getName(), getCars());
    }
}

To generate toString(), select toString() option from the Generate pop-up dialog:-

Again, there are several templates to choose from:-

Here’s an example of toString() using Guava:-

public final class Person {
    ...

    @Override
    public String toString() {
        return Objects.toStringHelper(this)
                .add("name", name)
                .add("cars", cars)
                .toString();
    }
}

The post IntelliJ IDEA 14.1: Better equals(), hashCode() and toString() appeared first on My Shitty Code.

By default, IntelliJ IDEA generates mutable classes and fields.

One of the steps to achieve immutability is to make all classes and fields to be final.

SOLUTION

Making Fields Final

Go to Preferences… -> Code Style -> Java -> Code Generation tab

Under Final Modifier, check both Make generated local variables final and Make generated parameters final.

Making Classes Final

Go to Preferences… -> File and Code Templates -> Templates tab

Select Class and add final.

The post IntelliJ IDEA: Generating Immutable Classes and Fields appeared first on My Shitty Code.