SPRING BOOT MULTI MODULE PROJECT

This project is still under development.

This project aims to help the developer to start with spring boot multi-module project quickly. Logging, Exception handling, security are enabled by default. As of now logging and security module are strictly tied to Microsoft azure. All logs and exceptions are continuously tracked in Microsoft Application Insight.

Anyone can take this skeleton, and can start developing Microservice with Spring Boot in no time, since they majorly need to focus on business logic. This project handles major cross-cutting concerns, and these are available under lib folder.

Add your Microservice under application folder. I have added one sample-service under application folder, that can used as a reference.

LIBRARIES

• api-docs
  • documentation
  • code
• file-handler
  • documentation
  • code
• exception
  • documentation
  • code
• logging
  • documentation
  • code
• security
  • documentation
  • code
• utility
  • documentation
  • code

How to bootstrap new Microservice

For Complete implementation, please check sample-service.

• Step 1: Clone this repository

• Step 2: Load Parent pon.xml

• Step 3: Create Maven Module

• Step 4: Replace pom.xml content

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>backend-parent</artifactId>
        <groupId>com.app</groupId>
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>../../pom.xml</relativePath>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>sample-service</artifactId> <!--Change the artificat name, if you want -->

    <dependencies>
        <!-- Enables basic Swagger UI, by adding @EnableDocs annotation on Main Class. For Advance configuration, check README file -->
        <dependency>
            <groupId>com.app</groupId>
            <artifactId>api-docs</artifactId>
            <version>${project.version}</version>
        </dependency>

        <!-- It contains security, logging and exception dependencies.-->
        <dependency>
            <groupId>com.app</groupId>
            <artifactId>backend-starter</artifactId>
            <version>${project.version}</version>
        </dependency>

        <!-- Check README file for details of this module. -->
        <dependency>
            <groupId>com.app</groupId>
            <artifactId>utility</artifactId>
            <version>${project.version}</version>
        </dependency>

        <!-- Uncomment this section, if you want support for azure blob storage. Check README file for detail usage. -->
       <!-- <dependency>
            <groupId>com.app</groupId>
            <artifactId>file-handler</artifactId>
            <version>${project.version}</version>
        </dependency>-->
    </dependencies>

    <build>
        <finalName>sample-service</finalName> <!--Change the name of the jar generated by build, if you want -->
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <layers>
                        <enable>true</enable>
                    </layers>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

• Step 5: Add application.yaml file under resource folder

spring:
  application:
    name: sample-service

  datasource:
    url: jdbc:h2:mem:testdb
    driver-class-name: org.h2.Driver
    username: test
    password: test
  jpa:
    database-platform: org.hibernate.dialect.H2Dialect
  h2:
    console:
      enabled: true
  autoconfigure:
    exclude:
      - org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration
      - org.springframework.boot.actuate.autoconfigure.security.servlet.ManagementWebSecurityAutoConfiguration


server:
  port: 8080
  servlet:
    session:
      cookie:
        http-only: true
        secure: true

app:
  version: 1.0.0
  security:
    enabled: true
  swagger:
    enable-auth: false
    title: Sample Service
    desc: Helps to interact with Backend
    version: v1
    path-mapping: /
    contact:
      name: Backend Team
      email: test@test.com
      url: ""
    license: null
    license-uri: null

• Step 6: Create Application.java class under root package

package sample_service;

import apidocs.annotations.EnableDocs;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import security.annotations.EnableSecurity;

@SpringBootApplication
@EnableDocs
@EnableSecurity // UnComment this, if you want to use Security Module. Please refer README for detailed instruction
public class Application {
    public static void main( String[] args ) { SpringApplication.run(Application.class, args);}
}

Library Documentation

This section explains the usage of different modules.

api-docs

Add below dependency to pom.xml

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>api-docs</artifactId>
    <version>${project.version}</version>
  </dependency>

Add below content to application.yml file, to modify the default value swagger variables

app:
  swagger:
    enable-auth: true
    title: Sample Service API
    desc: Helps to interact with Backend
    version: v1
    path-mapping: /
    oauth:
      client-id: '${backend-client-id}'
      client-key: '${backend-client}'
      resource: '${backend-resource}'
      login-endpoint: '${auth-url}'
    contact:
      name: Backend Team
      email: test@test.com
      url: ''
    license: null
    license-uri: null

Enable swagger by only adding @EnableDocs annotation on Main Class.

package sample_service;

import apidocs.annotations.EnableDocs;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableDocs
public class Application {
    public static void main( String[] args ) { SpringApplication.run(Application.class, args);}
}

URL: http://localhost:8080/swagger-ui/index.html

file-handler

Exceptions will be automatically handled by Exception Module

Add below dependency to pom.xml

<dependency>
     <groupId>com.app</groupId>
     <artifactId>file-handler</artifactId>
     <version>${project.version}</version>
 </dependency>

Add below content in application.yml file

azure:
  storage:
    account-name: ${blob-name} 
    account-key: ${blob-key}
    container-name: ${container-name}

Import FileUtil from file_handler.util

It has 3 functionality:

• Upload Blob

package file_handler;

import file_handler.util.FileUtil;

public class FileHandler {
  @Autowired
  private FileUtil fileUtil;
  public URI uploadBlob(MultipartFile file, String blobName) {
        return fileUtil.uploadFile(file, blobName);
  }
}

• Delete Blob

package file_handler;

import file_handler.util.FileUtil;

public class FileHandler {
  @Autowired
  private FileUtil fileUtil;

  public void delete(String url, String blobName) {
      fileUtil.deleteBlob(url, blobName);
  }
}

• Download Blob

package file_handler;

import file_handler.util.FileUtil;

public class FileHandler {
   @Autowired
   private FileUtil fileUtil;

    public ResponseEntity<Resource> download(String url, String blobName) {
        return fileUtil.downloadBlob(url, blobName);
    }
}
   

exception

It is already a part of backend starter

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>backend-starter</artifactId>
    <version>${project.version}</version>
  </dependency>

If you are not adding backend starter, then it can be added individually as well

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>exception</artifactId>
    <version>${project.version}</version>
  </dependency>

Below are the exception that are handled by this module:

System Exception

• ArrayIndexOutOfBoundsException
• IndexOutOfBoundsException
• NumberFormatException
• IllegalArgumentException
• AccessDeniedException
• NullPointerException
• MethodArgumentTypeMismatchException
• DataAccessException
• SQLServerException
• ConstraintViolationException
• HttpRequestMethodNotSupportedException
• HttpMediaTypeNotSupportedException
• MissingPathVariableException
• HttpMessageNotReadableException
• HttpMessageNotWritableException
• MissingServletRequestParameterException
• ConversionNotSupportedException
• TypeMismatchException
• MethodArgumentNotValidException
• MissingServletRequestPartException
• NoHandlerFoundException

Custom Exception

• InvalidStateTransitionException
• DuplicateRecordException
• EntityNotFoundException
• MultipleActionFailedException
• OperationNotAllowedException
• OperationFailedException
• FileHandlingException

logging

It is already a part of backend starter

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>backend-starter</artifactId>
    <version>${project.version}</version>
  </dependency>

If you are not adding backend starter, then it can be added individually as well

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>logging</artifactId>
    <version>${project.version}</version>
  </dependency>

Out of the box logging for Repository, Service, Controller and Components, once below dependency added to pom.xml, and for all other functions of classes use @Loggable annotation.

package sample_service.dto.mapper;

import logging.annotations.Loggable;
import sample_service.dto.model.AppModelDTO;
import sample_service.model.AppModel;

public class AppModelMapper {

    @Loggable
    public AppModel convertToModel(AppModelDTO modelDTO) {
        AppModel model = new AppModel();
        model.setId(modelDTO.getId());
        model.setName(modelDTO.getName());
        return model;
    }
}

@Loggable has 4 optional parameters, that can set, if want to log some different messages.

package sample_service.dto.mapper;

import logging.annotations.Loggable;
import sample_service.dto.model.AppModelDTO;
import sample_service.model.AppModel;

public class AppModelMapper {

    @Loggable(valueAfter = "Value After", valueAfterReturning = "Value After Returning", valueAround = "Value Around", valueBefore = "Value Before")
    public AppModel convertToModel(AppModelDTO modelDTO) {
        AppModel model = new AppModel();
        model.setId(modelDTO.getId());
        model.setName(modelDTO.getName());
        return model;
    }
}

It will be capturing following properties:

• class_name: Name of the class to which functions belong.
• method_name: Name of the method which is getting executed.
• parameters: Parameters of function.
• execution_time_in_ms: Time take by a function.
• microservice: Name of the microservice.
• request_id: Unique Id with every request, that will also help to trace logs in Application Insight, if used.
• version: Microservice version.
• message:
  • When function is starting: FUNCTIONNAME function started..
  • When function complete: FUNCTIONNAME function completed..
  • In case of error it will contain error message.
  • When Controller starts: FUNCTIONNAME event started..
  • When Controller completes: FUNCTIONNAME event completed..

In order to send logs to Application Insight, add below content to application.yml

azure:
  application-insights:
    instrumentation-key: ${appinsight-instrumentation-key}
    enabled: true

security

As of now it only supports v1 token.

It is already a part of backend starter

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>backend-starter</artifactId>
    <version>${project.version}</version>
  </dependency>

If you are not adding backend starter, then it can be added individually as well

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>security</artifactId>
    <version>${project.version}</version>
  </dependency>

Enable security by only adding @EnableSecurity annotation on Main Class.

Add below content to application.yaml, if you are enabling security module

spring:
  security.oauth2.client.registration.azure:
    client-id: '${client-id-dev}'
    client-secret: '${client-secret-dev}'
    client-name: Azure
azure:
  activedirectory:
    client-id: '${client-id-dev}'
    allow-telemetry: true
    client-secret: '${client-secret-dev}'
    user-group.allowed-groups: TEST_AZURE_AD_GROUP
    tenant-id: '${tenant-id-dev}'

If you want to disable out of box spring security, then add below content in application.yaml

spring:
  autoconfigure:
    exclude:
      - org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration
      - org.springframework.boot.actuate.autoconfigure.security.servlet.ManagementWebSecurityAutoConfiguration

package sample_service;

import apidocs.annotations.EnableDocs;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import security.annotations.EnableSecurity;

@SpringBootApplication
@EnableDocs
@EnableSecurity
public class Application {
    public static void main( String[] args ) { SpringApplication.run(Application.class, args);}
}

utility

Add below dependency to pom.xml, in order to add utility module

 <dependency>
    <groupId>com.app</groupId>
    <artifactId>utility</artifactId>
    <version>${project.version}</version>
  </dependency>

It has few important component:

• ValidList: Use this when you are adding any validators to an element of List.

package sample_service.controller.v1.api;

import utility.annotations.ControllerV1;

@ControllerV1
public class AppController {

  @PostMapping(path = "/user")
    public ResponseEntity<ResponseDTO> setUsersDetail(@Valid @RequestBody ValidList<AppRequest> request) {
    
        return new ResponseEntity( ResponseDTO.setResponseDTO(
                Messages.setMessage(EntityType.USER, ActionType.CREATED, "")),
                HttpStatus.CREATED
        );
    }}

• ResponseDTO: Use this DTO, for returning response to Users, for POST, PUT, PATCH, DELETE actions. It has a static method setResponseDTO that can be used, to set the message in response, other fields will be set by default.
  • status: HttpStatus (This will be set to CREATED by default)
  • message: String ( Use setResponseDTO method to set this value, this a static method. ResponseDTO.setResponseDTO( Messages.setMessage(EntityType.USER, ActionType.CREATED, ""))).
  • timestamp: Date (This will set to current timestamp by default. It uses "dd-MM-yyyy hh:mm:ss Z" format).
  • requestId: String ( This will be set by default to unique value for every request. e.g. 123e4567-e89b-12d3-a456-556642440000 )
  • detailMessage: List

package sample_service.controller.v1.api;

import utility.annotations.ControllerV1;

@ControllerV1
public class AppController {

  @PostMapping(path = "/user")
    public ResponseEntity<ResponseDTO> setUsersDetail(@Valid @RequestBody ValidList<AppRequest> request) {
    
        return new ResponseEntity( ResponseDTO.setResponseDTO(
                Messages.setMessage(EntityType.USER, ActionType.CREATED, "")),
                HttpStatus.CREATED
        );
    }}