How to Integrate Angular with Spring Boot Rest API

In this tutorial, I will show you step by step to integrate Angular project with Spring Boot Rest API so that Spring Boot and Angular will run in one project. You will also know how to configure Angular SPA Routing to avoid Whitelabel Error Page.

Other versions:
– Integrate Angular 8 with Spring Boot Rest API
– Integrate Angular 10 with Spring Boot Rest API
– Integrate Angular 11 with Spring Boot Rest API
– Integrate Angular 12 with Spring Boot Rest API

– Angular 10 + Spring Boot + MySQL example
– Angular 10 + Spring Boot + PostgreSQL example
– Angular 10 + Spring Boot + MongoDB example
– Angular 10 + Spring Boot: Pagination example
– Angular 10 + Spring Boot: JWT Authentication example
– Angular 10 + Spring Boot: File upload example

– Angular 11 + Spring Boot + MySQL example
– Angular 11 + Spring Boot + PostgreSQL example
– Angular 11 + Spring Boot + MongoDB example
– Angular 11 + Spring Boot: Pagination example
– Angular 11 + Spring Boot: JWT Authentication example
– Angular 11 + Spring Boot: File upload example

– Angular 12 + Spring Boot + H2 example
– Angular 12 + Spring Boot + MySQL example
– Angular 12 + Spring Boot + PostgreSQL example
– Angular 12 + Spring Boot + MongoDB example
– Angular 12 + Spring Boot: Pagination example
– Angular 12 + Spring Boot: JWT Authentication example
– Angular 12 + Spring Boot: File upload example

Contents

Angular & Spring Boot application Overview
Technology Stack
Setup Angular Client
Import Angular Project to Spring Tool Suite
Setup Spring Boot Server
Integrate Angular with Spring Boot Rest API
- Build Angular App
- Integrate Angular production into Spring Boot Project
Run and Check Result
Spring Boot + Angular: Whitelabel Error Page
Conclusion
Further Reading

Angular & Spring Boot application Overview

Assume that we have 2 projects: Angular & Spring Boot:

For example, if we run them separately:

Spring Boot Server exports Rest Apis at Url: http://localhost:8080/
Angular Client runs at url: http://localhost:8081/

Using Angular to call Spring Rest API:

Otherwise, when deploying Angular production-build with Spring Boot project, we only need to run Spring Boot Project for the fullstack (Angular + Spring Boot) system.

In this example, we access http://localhost:8080/.

Technology Stack

Node.js
Angular 8
Spring Boot 2
Spring Tool Suite
Maven 3.6.1

Setup Angular Client

You can use your own Angular Project, or just download the source code on Github, or follow these steps to create a new one.

Open cmd and use Angular CLI to create a new Angular Project as following command:

ng new Angular8Client
? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? CSS

We also need to generate some Components and Services:

ng g s services/tutorial

ng g c components/add-tutorial
ng g c components/tutorial-details
ng g c components/tutorials-list

Now you can see that our project directory structure looks like this-

Because I want to keep this tutorial simple and brief, please continue to develop this App with instruction in the post:
Angular 8 CRUD Application example with Web API

Import Angular Project to Spring Tool Suite

Open Spring Tool Suite, right click on Package Explorer and choose Import -> General -> Projects from Folder or Archieve, press Next.

Find the Angular Project that we’ve just created above and press Finish, angular-8-client is imported like this:

To clean the source code in STS, we need to remove node_modules folder by following the steps:

Right click on angular-8-client project, choose Properties, then Resource -> Resource Filter.
Press Add Filter…, choose Filter Type: Exclude all, Applies to: Files and folders, and check All children (recursive), with ‘File and Folder Atributes’, we specify node_modules:

Press OK, then Apply, the result will be like this:

Setup Spring Boot Server

You can use your own Spring Boot Project, or just download the source code on Github, or follow these steps to create a new one.

Use Spring web tool or your development tool (Spring Tool Suite, Eclipse, Intellij) to create a Spring Boot project.

Then open pom.xml and add these dependencies:

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

The instruction can be found in the post:
Spring Boot, Spring Data JPA – Rest CRUD API example

Now we have 2 projects together in Spring Tool Suite:

Let’s continue to the most important part.

Integrate Angular with Spring Boot Rest API

Build Angular App

Currently Angular Client and Spring Boot server work independently on ports 8081 and 8080.

The first thing we need to do is to build Angular App for production.
There are 2 steps:
– Set the output directory to static folder:
Open angular.json, add the "outputPath": "./static" option to the build target so that the production will be stored in static folder under project root directory.

{
  ...
  "projects": {
    "Angular8ClientCrud": {
      ...
      "architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "./static",
            "index": "src/index.html",
            "main": "src/main.ts",
            ...
          },
          "configurations": {
            ...
          }
        },
        ...
      }
    }},
  "defaultProject": "Angular8ClientCrud"
}

– Run command ng build --prod.

Generating ES5 bundles for differential loading...
ES5 bundle generation complete.

chunk {2} polyfills-es2015.5b10b8fd823b6392f1fd.js (polyfills) 36.2 kB [initial] [rendered]
chunk {3} polyfills-es5.8e50a9832860f7cf804a.js (polyfills-es5) 126 kB [initial] [rendered]
chunk {0} runtime-es2015.c5fa8325f89fc516600b.js (runtime) 1.45 kB [entry] [rendered]
chunk {0} runtime-es5.c5fa8325f89fc516600b.js (runtime) 1.45 kB [entry] [rendered]
chunk {1} main-es2015.1fc85a54f08d1dacb8cd.js (main) 280 kB [initial] [rendered]
chunk {1} main-es5.1fc85a54f08d1dacb8cd.js (main) 345 kB [initial] [rendered]
chunk {4} styles.3ff695c00d717f2d2a11.css (styles) 0 bytes [initial] [rendered]
Date: 2020-05-30T15:34:14.655Z - Hash: 86d212a6faf72b219de3 - Time: 90679ms

Now you can see new static folder with content as following:

Integrate Angular production into Spring Boot Project

Now we need to copy all files from Angular static folder to src/target/classes/static folder of Spring Boot project.

There are 2 way to do this:

Manually copy/paste
Using maven-resources-plugin

Open pom.xml, add following plugin:

<build>
  <plugins>
    <plugin>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
    </plugin>

    <plugin>
      <artifactId>maven-resources-plugin</artifactId>
      <executions>
        <execution>
          <id>copy-resources</id>
          <phase>validate</phase>
          <goals>
            <goal>copy-resources</goal>
          </goals>
          <configuration>
            <outputDirectory>${basedir}/target/classes/static/</outputDirectory>
            <resources>
              <resource>
                <directory>${basedir}/../angular-8-client/static</directory>
              </resource>
            </resources>
          </configuration>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

In the code above, we specify outputDirectory for the destination folder, and resource>directory for the source folder.

Run and Check Result

Build and run the Spring Boot server with commands:
– mvn clean install
– mvn spring-boot:run

Open browser with url: http://localhost:8080/.
The result:

Spring Boot + Angular: Whitelabel Error Page

Oh yeah! Everything looks good.
But wait, let’s try to refresh the page.
What happened?

To handle this error, we’re gonna enable hash(#) in App Routing module.

– Open app-routing.module.ts
– Pass optional parameter useHash as true value.

@NgModule({
  imports: [RouterModule.forRoot(routes, {useHash: true})],
  exports: [RouterModule]
})

Our Url is hashed(#) after port number: http://localhost:8080/#/tutorials

Now you can refresh the page without worrying about Whitelabel Error.

Conclusion

Today we’ve learned how to integrate Spring Boot Project with Angular 8 Application in one Project. We also handle “Whitelabel Error Page” case for Spring Boot + Angular Project.

There are many Spring Boot + Angular examples that you can apply this approach to integrate:
– Angular 8 + Spring Boot: JWT Authentication example
– Angular 8 + Spring Boot + MySQL example
– Angular 8 + Spring Boot + PostgreSQL example
– Angular 8 + Spring Boot + MongoDB CRUD example
– Angular 8 + Spring Boot: Pagination example
– Angular 8 + Spring Boot: File upload example

– Angular 11 + Spring Boot + MySQL example
– Angular 11 + Spring Boot + PostgreSQL example
– Angular 11 + Spring Boot + MongoDB example
– Angular 11 + Spring Boot: JWT Authentication example
– Angular 11 + Spring Boot: Pagination example
– Angular 11 + Spring Boot: File upload example

4 thoughts to “How to Integrate Angular with Spring Boot Rest API”

Mack says:

August 3, 2021 at 7:08 am

Awesome,Thanks
Alexander says:

December 11, 2020 at 1:24 pm

Kudos! It’s really appreciated to have such a good working example. My honest regards. Appealing!
vidyesh says:

October 10, 2020 at 7:53 am

Sorry it work fine i was trying to access wrong url.. but now it work fine.. I found Only your tutorial is working as i expected.. Thank You Sir..
vidyesh says:

October 10, 2020 at 7:49 am

I imorted your both projects and application run

my spring boot run on port 8083
After that i follwed process as you said but i can not able to run frontend at port localhost :8083
It gives error messsage
Should i need to change port at the frontend?

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