@PathVariable and @RequestParam annotations in Spring Boot

In this post we will see @PathVariable and @RequestParam annotations in Spring Boot.

Basic points about @PathVariable and @RequestParam annotations.

@PathVariable annotation-

  • This annotation introduced in Spring  3.0, available in org.springframework.web.bind.annotation package.
  • Optional elements  ( name, required, value).
  • This annotation used as a method parameter.
  • It takes placeholder value from URI.
  • The example of rest URI when we use @PathVariable – http://localhost:9093/rest/listofbooks/{bookId}

@RequestaParam annotation-

  • This annotation introduced in Spring  2.5, available in org.springframework.web.bind.annotation package.
  • Optional elements  (name, required, value).
  • This annotation used as a method parameter.
  • It takes parameter value from URI.
  • The example of rest URI when we use @RequestParam –

– http://localhost:9093/rest/listofbooks/{bookId}/book?bookName=book1

 

@PathVariable annotations Example in Spring Boot.

prerequisites –

  • JDK 1.8
  • Eclipse
  • maven
  • postman

 

Create maven project, Don’t forget to check ‘Create a simple project (skip)’click on next. Fill all details(GroupId – pathvariableexample, ArtifactId – pathvariableexample and name – pathvariableexample) and click on finish. Keep packaging as the jar.

Modify the 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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>pathvariableexample</groupId>
  <artifactId>pathvariableexample</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>pathvariableexample</name>
  
  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
 </parent>
  <dependencies>
	<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
       
        
   </dependencies>
 
    
   
</project>

 

Define classes.

Book.java

package pathvariableexample;

public class Book {
	int bookId;
	String bookName;
	String bookPrice;
	public int getBookId() {
		return bookId;
	}
	public void setBookId(int bookId) {
		this.bookId = bookId;
	}
	public String getBookName() {
		return bookName;
	}
	public void setBookName(String bookName) {
		this.bookName = bookName;
	}
	public String getBookPrice() {
		return bookPrice;
	}
	public void setBookPrice(String bookPrice) {
		this.bookPrice = bookPrice;
	}
	
}

 

BookController.java


package pathvariableexample;

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import java.util.*;

@RestController
@RequestMapping(value = "/rest")
public class BookController {

	@RequestMapping(value = "/book/{bookId}",method = RequestMethod.GET)
    public Book getBookById(@PathVariable int bookId) {
		
		List<Book> listBook = createBook();
		for(Book book : listBook) {
			if(book.getBookId() == 1) {
				return book;
			}
		}
    	
    	return null;
    	
		
	}
	
	public List<Book> createBook() {
		
    	Book book = new Book();
    	book.setBookId(1);
    	book.setBookName("book1");
    	book.setBookPrice("100");
    	
    	Book book1 = new Book();
    	book1.setBookId(2);
    	book1.setBookName("book2");
    	book1.setBookPrice("200");
    	List<Book> bookList = new ArrayList<Book>();
    	bookList.add(book);
    	bookList.add(book1);
    	
    	return bookList;
    	
	}
}

 

SpringMain.java

package pathvariableexample;


import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class SpringMain {
	public static void main(final String[] args) {
		final ConfigurableApplicationContext configurableApplicationContext = SpringApplication
				.run(SpringMain.class, args);
		 
		 
	}
}

 

If you encounter any port related issue, define application.properties and change the port.

application.properties

server.port = 9093

Run the SpringMain class and deploy the server.

Test the rest URI.

@PathVariable and @RequestParam annotations in Spring Boot


@RequestParam example in Spring Boot.

Let’s modify the controller class.

BookController.java

package pathvariableexample;

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.*;

@RestController
@RequestMapping(value = "/rest")
public class BookController {

	@RequestMapping(value = "/listofbooks/{bookId}/book",method = RequestMethod.GET)
    public Book getBookById(
    		@PathVariable int bookId, 
    		@RequestParam String bookName) {
		
		List<Book> listBook = createBook();
		for(Book book : listBook) {
			System.out.println("bookIs is ---"+bookId);
			System.out.println("bookName is ---"+bookName);
			if(book.getBookId() == 1 && book.getBookName().equals(bookName)) {
				return book;
			}
		}
    	
    	return null;
    	
		
	}
	
	public List<Book> createBook() {
		
    	Book book = new Book();
    	book.setBookId(1);
    	book.setBookName("book1");
    	book.setBookPrice("100");
    	
    	Book book1 = new Book();
    	book1.setBookId(2);
    	book1.setBookName("book2");
    	book1.setBookPrice("200");
    	List<Book> bookList = new ArrayList<Book>();
    	bookList.add(book);
    	bookList.add(book1);
    	
    	return bookList;
    	
	}
}

 

@PathVariable and @RequestParam annotations in Spring Boot

That’s all about @PathVariable and @RequestParam annotations in Spring Boot. You may like.

@PathVariable docs.