How to Create Spring RESTful API without using Spring Boot

Most Spring Tutorials available online teach you how to create/secure a Rest API with Spring boot. However, sometimes there will be specific use cases where you will need to create/secure REST API without using spring boot. This tutorial aims to help you create a REST application without using Spring Boot at all.

Note: If you don’t wanna use even the Spring framework, then you can read on how to create REST API in Java without Spring.

What you’ll build

A Spring REST service which will simply accept a name as a path variable in the request and say hello with that name in the response

What you’ll need

Spring Tool Suite 4
JDK 11
MySQL Server 8
Maven

Tech Stack

Spring 5
JDK 11
Log4j 2

Bootstrap your application

Let’s bootstrap the application by creating a maven project in STS

Project Dependencies

pom.xml

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.favtuts</groupId>
  <artifactId>spring-rest-jwt-demo</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>spring-rest-jwt-demo Maven Webapp</name>
  <url>http://maven.apache.org</url>
    <properties>
        <java-version>11</java-version>
        <spring.version>5.2.3.RELEASE</spring.version>
        <hibernate.version>5.4.1.Final</hibernate.version>
    </properties>
    <dependencies>
        <!-- Spring Web MVC -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- Required for converting JSON data to Java object and vice versa -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.10.1</version>
        </dependency>
        <!-- Servlet API -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>SpringRestJwt</finalName>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>2.3.2</version>
                    <configuration>
                        <source>${java-version}</source>
                        <target>${java-version}</target>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>3.2.3</version>
                    <configuration>
                        <warSourceDirectory>src/main/webapp</warSourceDirectory>
                        <warName>SpringRestJwt</warName>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

Spring Configuration

SpringWebInitializer.java

WebApplicationContext can be configured using web.xml or Java-based configuration as shown below

SpringWebInitializer class extends Spring’s AbstractAnnotationConfigDispatcherServletInitializer to configure the WebApplicationContext. Ezoic

123456789101112131415161718192021 packagecom.javachinna.config;importorg.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;publicclassSpringWebInitializer extendsAbstractAnnotationConfigDispatcherServletInitializer { @Override protectedClass[] getServletConfigClasses() { returnnewClass[] { WebConfig.class}; } @Override protectedString[] getServletMappings() { returnnewString[] { "/"}; } @Override protectedClass[] getRootConfigClasses() { returnnewClass[] {}; }}

Ezoic

WebConfig.java

WebConfig class implements WebMvcConfigurer to configure the Jackson message converters

@EnableWebMvc annotation is used to enable Spring MVC support

@ComponentScan annotation is used with the @Configuration annotation to tell Spring the packages to scan for annotated components.

123456789101112131415161718192021 packagecom.javachinna.config;importjava.util.List;importorg.springframework.context.annotation.ComponentScan;importorg.springframework.context.annotation.Configuration;importorg.springframework.http.converter.HttpMessageConverter;importorg.springframework.http.converter.json.MappingJackson2HttpMessageConverter;importorg.springframework.web.servlet.config.annotation.EnableWebMvc;importorg.springframework.web.servlet.config.annotation.WebMvcConfigurer;@EnableWebMvc@Configuration@ComponentScan("com.javachinna")publicclassWebConfig implementsWebMvcConfigurer { @Override publicvoidconfigureMessageConverters(List<HttpMessageConverter<?>> converters) { converters.add(newMappingJackson2HttpMessageConverter()); }}

Ezoic

Create REST Controller

GreetController.java

Controller class for exposing a GET REST API Ezoic

1234567891011121314151617181920 packagecom.javachinna.controller;importorg.apache.log4j.Logger;importorg.springframework.ui.ModelMap;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.PathVariable;importorg.springframework.web.bind.annotation.RestController;@RestControllerpublicclassGreetController { privateLogger logger = Logger.getLogger(GreetController.class); @GetMapping("/greet/{name}") publicString greet(@PathVariableString name, ModelMap model) { String greet = "Hello!!! "+ name + " How are You?"; logger.info(greet); returngreet; }}

Log4J Configuration

log4j.properties

12345678910111213141516 # Root logger optionlog4j.rootLogger=DEBUG, stdout, file# Redirect log messages to consolelog4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.outlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n# Redirect log messages to a log filelog4j.appender.file=org.apache.log4j.RollingFileAppender#outputs to Tomcat homelog4j.appender.file.File=${catalina.home}/logs/myapp.loglog4j.appender.file.MaxFileSize=5MBlog4j.appender.file.MaxBackupIndex=10log4j.appender.file.layout=org.apache.log4j.PatternLayoutlog4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

Ezoic

Build Application

Run mvn clean install command to clean and build the war file

Deploy Application

Deploy the generated war file in a server like tomcat and hit the URL http://localhost:8080/SpringRestJwt/greet/Chinna

Conclusion

That’s all folks. In this article, we have developed a simple Spring REST service without using Spring Boot. Thank you for reading

How to Create Spring RESTful API without using Spring Boot

What you’ll build

What you’ll need

Tech Stack

Bootstrap your application