Spring @GetMapping

last modified October 18, 2023

In this article we show how to use @GetMapping annotation to map HTTP GET requests onto specific handler methods.

Spring is a popular Java application framework for creating enterprise applications.

@GetMapping

@GetMapping annotation maps HTTP GET requests onto specific handler methods. It is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.GET).

Spring @GetMapping example

The following application uses @GetMapping to map two request paths onto handler methods. In this example, we use annotations to set up a Spring web application.

pom.xml
src
├───main
│ ├───java
│ │ └───com
│ │ └───zetcode
│ │ ├───config
│ │ │ MyWebInitializer.java
│ │ │ WebConfig.java
│ │ └───controller
│ │ MyController.java
│ └───resources
│ logback.xml
└───test
 └───java
 └───com
 └───zetcode
 └───controller
 MyControllerTest.java

This is the project structure.

<?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">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.zetcode</groupId>
 <artifactId>getmapping</artifactId>
 <version>1.0-SNAPSHOT</version>
 <packaging>war</packaging>
 <properties>
 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 <maven.compiler.source>17</maven.compiler.source>
 <maven.compiler.target>17</maven.compiler.target>
 <spring-version>5.3.23</spring-version>
 </properties>
 <dependencies>
 <dependency>
 <groupId>ch.qos.logback</groupId>
 <artifactId>logback-classic</artifactId>
 <version>1.4.0</version>
 </dependency>
 <dependency>
 <groupId>javax.servlet</groupId>
 <artifactId>javax.servlet-api</artifactId>
 <version>4.0.1</version>
 <scope>provided</scope>
 </dependency>
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <version>4.12</version>
 <scope>test</scope>
 </dependency>
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-webmvc</artifactId>
 <version>${spring-version}</version>
 </dependency>
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-test</artifactId>
 <version>${spring-version}</version>
 </dependency>
 </dependencies>
 <build>
 <plugins>
 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-war-plugin</artifactId>
 <version>3.3.2</version>
 </plugin>
 <plugin>
 <groupId>org.eclipse.jetty</groupId>
 <artifactId>jetty-maven-plugin</artifactId>
 <version>9.4.49.v20220914</version>
 </plugin>
 </plugins>
 </build>
</project>

In the pom.xml file we have the following dependencies: logback-classic, javax.servlet-api, junit, spring-webmvc, and spring-test.

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
 <logger name="org.springframework" level="ERROR"/>
 <logger name="com.zetcode" level="INFO"/>
 <appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
 <encoder>
 <Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n
 </Pattern>
 </encoder>
 </appender>
 <root>
 <level value="INFO" />
 <appender-ref ref="consoleAppender" />
 </root>
</configuration>

The logback.xml is a configuration file for the Logback logging library.

package com.zetcode.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
@Configuration
public class MyWebInitializer extends
 AbstractAnnotationConfigDispatcherServletInitializer {
 @Override
 protected Class<?>[] getRootConfigClasses() {
 return null;
 }
 @Override
 protected Class<?>[] getServletConfigClasses() {
 return new Class[]{WebConfig.class};
 }
 @Override
 protected String[] getServletMappings() {
 return new String[]{"/"};
 }
}

MyWebInitializer registers the Spring DispatcherServlet, which is a front controller for a Spring web application.

@Override
protected Class<?>[] getServletConfigClasses() {
 return new Class[]{WebConfig.class};
}

The getServletConfigClasses returns a web configuration class.

package com.zetcode.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.zetcode"})
public class WebConfig {
}

The WebConfig enables Spring MVC annotations with @EnableWebMvc and configures component scanning for the com.zetcode package.

package com.zetcode.controller;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class MyController {
 @GetMapping(value="/", produces = MediaType.TEXT_PLAIN_VALUE)
 public String index() {
 return "This is Home page";
 }
 @GetMapping(value="/hello", produces = MediaType.TEXT_PLAIN_VALUE)
 public String sayHello() {
 return "Hello there!";
 }
}

MyController provides mappings between request paths and handler methods.

@RestController
public class MyController {

@RestController is used for creating restful controllers, which do not use a view technology. The methods typically return XML, JSON, or plain text.

@GetMapping(value="/", produces = MediaType.TEXT_PLAIN_VALUE)
public String index() {
 return "This is Home page";
}

The @GetMapping maps a / root path from a GET request to the index method. It returns a plain text.

package com.zetcode.controller;
import org.junit.Before;
import org.junit.Test;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
public class MyControllerTest {
 private MockMvc mockMvc;
 @Before
 public void setup() {
 this.mockMvc = MockMvcBuilders.standaloneSetup(new MyController()).build();
 }
 @Test
 public void testHomePage() throws Exception {
 this.mockMvc.perform(get("/")).andExpect(status().isOk())
 .andExpect(content().string("This is Home page"));
 }
 @Test
 public void testHelloPage() throws Exception {
 this.mockMvc.perform(get("/hello")).andExpect(status().isOk())
 .andExpect(content().string("Hello there!"));
 }
}

MyControllerTest tests the two pages.

$ curl localhost:8080
This is Home page
$ curl localhost:8080/hello
Hello there!

We run the application and create two GET requests with curl tool.

In this article we have presented the @GetMapping annotation.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

List all Spring tutorials.