Spring @RequestHeader tutorial
last modified July 9, 2020
Spring @RequestHeader tutorial shows how to bind method parameters to request headers with @RequestHeader annotation.
Spring is a popular Java application framework for creating enterprise applications.
Spring @RequestHeader
@RequestHeader
annotation binds request header values to method
parameters. If the method parameter is Map<String, String>
,
MultiValueMap<String, String>
, or HttpHeaders
then the map is populated with all header names and values.
Spring @RequestHeader example
The application binds request body headers to method parameters.
Requests are created with curl
tool.
pom.xml src ├───main │ ├───java │ │ └───com │ │ └───zetcode │ │ ├───config │ │ │ MyWebInitializer.java │ │ │ WebConfig.java │ │ └───controller │ │ MyController.java │ └───resources │ logback.xml └───test └───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>springrequestheader</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>11</maven.compiler.source> <maven.compiler.target>11</maven.compiler.target> <spring-version>5.1.3.RELEASE</spring-version> </properties> <dependencies> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.2.3</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>4.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.3.RELEASE</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <groupId>org.eclipse.jetty</groupId> <artifactId>jetty-maven-plugin</artifactId> <version>9.4.14.v20181114</version> </plugin> </plugins> </build> </project>
We declare the necessary dependencies in pom.xml
.
<?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.
package com.zetcode.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.config.annotation.WebMvcConfigurer; @Configuration @EnableWebMvc @ComponentScan(basePackages = {"com.zetcode"}) public class WebConfig implements WebMvcConfigurer { }
The WebConfig
enables Spring MVC annotations with @EnableWebMvc
and configures component scanning for the com.zetcode
package.
package com.zetcode.controller; package com.zetcode.controller; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.HttpStatus; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestHeader; import org.springframework.web.bind.annotation.ResponseStatus; import org.springframework.web.bind.annotation.RestController; import java.util.Map; @RestController public class MyController { private static final Logger logger = LoggerFactory.getLogger(MyController.class); @GetMapping(value = "/agent") @ResponseStatus(value = HttpStatus.OK) public void client(@RequestHeader(value="User-Agent") String userAgent) { logger.info("User agent is: {}", userAgent); } @GetMapping(value = "/all") @ResponseStatus(value = HttpStatus.OK) public void all(@RequestHeader Map<String, String> headers) { logger.info("All headers: {}", headers); } }
We have two mappings. The first mapping determines the user agent, the second mapping finds out all request headers sent.
public void client(@RequestHeader(value="User-Agent") String userAgent) {
With the value parameter of the @RequestHeader
, we look for a specific
header; in our case, a User-Agent
.
public void all(@RequestHeader Map<String, String> headers) {
When providing a map, we retrieve all headers.
$ mvn jetty:run
We start the server.
$ curl localhost:8080/agent
We create a request to the first mapping.
08:26:29.926 INFO com.zetcode.controller.MyController - User agent is: curl/7.55.1
We get this log.
$ curl localhost:8080/all
We invoke the second mapping.
08:27:26.564 INFO com.zetcode.controller.MyController - All headers: {User-Agent=curl/7.55.1, Accept=*/*, Host=localhost:8080}
We have three headers logged.
In this tutorial, we have used the @RequestHeader
annotation to bind request headers
to method parameters.
List all Spring tutorials.