creating spring rest services without using spring boot

You don't need Spring Boot to create a rest controller.

Please follow the spring framework documentation on how to setup MVChttps://docs.spring.io/spring/docs/current/spring-framework-reference/web.html#spring-web

The MVC setup (the DispatcherServlet) depends on your spring version, you can either use xml or you can setup programmatically:https://docs.spring.io/spring/docs/current/spring-framework-reference/web.html#mvc-servlet

Once this is setup, you can add a rest controller to your application. Note that a rest controller (the @RestController annotation) is a stereotype annotation that combines @ResponseBody and @Controller, in other words the Controller returns an object in the response body instead of returning a view.

This is a perfect example explaining what I said above:http://www.programming-free.com/2014/01/spring-mvc-40-restful-web-services.html

Here is another example:

Directory Layout:

.├── ./pom.xml└── ./src    └── ./src/main        ├── ./src/main/java        │   └── ./src/main/java/biz        │       └── ./src/main/java/biz/tugay        │           └── ./src/main/java/biz/tugay/restfulspring        │               └── ./src/main/java/biz/tugay/restfulspring/config        │                   ├── ./src/main/java/biz/tugay/restfulspring/config/RestfulHello.java        │                   └── ./src/main/java/biz/tugay/restfulspring/config/WebAppInitalizer.java        └── ./src/main/webapp            └── ./src/main/webapp/WEB-INF                └── ./src/main/webapp/WEB-INF/web.xml

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>biz.tugay</groupId>    <artifactId>restfulSpring</artifactId>    <packaging>war</packaging>    <version>1.0-SNAPSHOT</version>    <name>restfulSpring Maven Webapp</name>    <url>http://maven.apache.org</url>    <dependencies>        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>javax.servlet-api</artifactId>            <version>3.0.1</version>            <scope>provided</scope>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-core</artifactId>            <version>4.3.16.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-context</artifactId>            <version>4.3.16.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-web</artifactId>            <version>4.3.16.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-webmvc</artifactId>            <version>4.3.16.RELEASE</version>        </dependency>    </dependencies>    <build>        <finalName>restfulSpring</finalName>        <plugins>            <plugin>                <groupId>org.apache.maven.plugins</groupId>                <artifactId>maven-compiler-plugin</artifactId>                <version>3.1</version>                <configuration>                    <source>1.7</source>                    <target>1.7</target>                </configuration>            </plugin>            <plugin>                <groupId>org.eclipse.jetty</groupId>                <artifactId>jetty-maven-plugin</artifactId>                <version>9.2.1.v20140609</version>            </plugin>        </plugins>    </build></project>

web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://java.sun.com/xml/ns/javaee"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee                             http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"         version="3.0"></web-app>

WebAppInitalizer.java

package biz.tugay.restfulspring.config;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;@Configuration@EnableWebMvc@ComponentScan("biz.tugay.restfulspring")public class WebAppInitalizer extends AbstractAnnotationConfigDispatcherServletInitializer {    @Override    protected String[] getServletMappings() {        return new String[]{"/*"};    }    @Override    protected Class<?>[] getRootConfigClasses() {        return new Class<?>[]{WebAppInitalizer.class};    }    @Override    protected Class<?>[] getServletConfigClasses() {        return new Class[0];    }}

RestfulHello.java

package biz.tugay.restfulspring.config;import org.springframework.http.HttpHeaders;import org.springframework.http.HttpStatus;import org.springframework.http.MediaType;import org.springframework.http.ResponseEntity;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestController@RequestMapping(value = "/")public class RestfulHello {    @RequestMapping(value = "hello")    public ResponseEntity<String> sayHello() {        final HttpHeaders httpHeaders= new HttpHeaders();        httpHeaders.setContentType(MediaType.APPLICATION_JSON);        return new ResponseEntity<String>("{\"msg\": \"Hello World\"}", httpHeaders, HttpStatus.OK);    }}

Build and run:

mvn clean installmvn jetty:start

Test:

> GET /hello HTTP/1.1> Host: localhost:8080> User-Agent: insomnia/5.15.0> Accept: */*< HTTP/1.1 200 OK< Date: Fri, 27 Apr 2018 00:06:07 GMT< Content-Type: application/json< Content-Length: 22< Server: Jetty(9.2.1.v20140609)

Content received:

{    "msg": "Hello World"}