Spring Boot Ajax example

This article will show you how to use jQuery.ajax to send a HTML form request to a Spring REST API and return a JSON response.

Tools used :

  1. Spring Boot 1.5.1.RELEASE
  2. Spring 4.3.6.RELEASE
  3. Maven 3
  4. jQuery
  5. Bootstrap 3
Note
You may interest at this classic Spring MVC Ajax example

1. Project Structure

A standard Maven project structure.

spring boot ajax example

2. Project Dependency

A normal Spring Boot dependency and some webjars resources.

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.mkyong</groupId>
    <artifactId>spring-boot-ajax-example</artifactId>
    <packaging>jar</packaging>
    <version>1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.1.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>2.2.4</version>
        </dependency>

        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>3.3.7</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <!-- Package as an executable jar/war -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

3. Spring REST API

3.1 A REST controller, accept a SearchCriteria and return a ResponseEntity

SearchController.java

package com.mkyong.controller;

import com.mkyong.model.AjaxResponseBody;
import com.mkyong.model.SearchCriteria;
import com.mkyong.model.User;
import com.mkyong.services.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.Errors;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;
import java.util.List;
import java.util.stream.Collectors;

@RestController
public class SearchController {

    UserService userService;

    @Autowired
    public void setUserService(UserService userService) {
        this.userService = userService;
    }

    @PostMapping("/api/search")
    public ResponseEntity<?> getSearchResultViaAjax(
            @Valid @RequestBody SearchCriteria search, Errors errors) {

        AjaxResponseBody result = new AjaxResponseBody();

        //If error, just return a 400 bad request, along with the error message
        if (errors.hasErrors()) {

            result.setMsg(errors.getAllErrors()
                        .stream().map(x -> x.getDefaultMessage())
                        .collect(Collectors.joining(",")));

            return ResponseEntity.badRequest().body(result);

        }

        List<User> users = userService.findByUserNameOrEmail(search.getUsername());
        if (users.isEmpty()) {
            result.setMsg("no user found!");
        } else {
            result.setMsg("success");
        }
        result.setResult(users);

        return ResponseEntity.ok(result);

    }

}

3.2 Some POJO.

AjaxResponseBody.java

package com.mkyong.model;

import java.util.List;

public class AjaxResponseBody {

    String msg;
    List<User> result;

    //getters and setters

}
User.java

package com.mkyong.model;

public class User {

    String username;
    String password;
    String email;

    public User(String username, String password, String email) {
        this.username = username;
        this.password = password;
        this.email = email;
    }

    //getters and setters
}

3.3 Validation.

SearchCriteria.java

package com.mkyong.model;

import org.hibernate.validator.constraints.NotBlank;

public class SearchCriteria {

    @NotBlank(message = "username can't empty!")
    String username;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

3.4 A service to init some users for searching.

UserService.java

package com.mkyong.services;

import com.mkyong.model.User;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

@Service
public class UserService {

    private List<User> users;

    // Love Java 8
    public List<User> findByUserNameOrEmail(String username) {

        List<User> result = users.stream()
            .filter(x -> x.getUsername().equalsIgnoreCase(username))
            .collect(Collectors.toList());

        return result;

    }

    // Init some users for testing
    @PostConstruct
    private void iniDataForTesting() {

        users = new ArrayList<User>();

        User user1 = new User("mkyong", "password111", "mkyong@yahoo.com");
        User user2 = new User("yflow", "password222", "yflow@yahoo.com");
        User user3 = new User("laplap", "password333", "mkyong@yahoo.com");

        users.add(user1);
        users.add(user2);
        users.add(user3);

    }

}

3.5 Spring Boot Starter.

UserService.java

package com.mkyong;

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

@SpringBootApplication
public class SpringBootWebApplication {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(SpringBootWebApplication.class, args);
    }

}

4. HTML form + jQuery Ajax

4.1 A simple HTML form, decorated with bootstrap.

ajax.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

<head>
    <title>Spring Boot ajax example</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>

    <link rel="stylesheet" type="text/css"
          href="webjars/bootstrap/3.3.7/css/bootstrap.min.css"/>
</head>
<body>

<nav class="navbar navbar-inverse">
    <div class="container">
        <div class="navbar-header">
            <a class="navbar-brand" href="#">Mkyong.com</a>
        </div>
    </div>
</nav>

<div class="container" style="min-height: 500px">

    <div class="starter-template">
        <h1>Spring Boot AJAX Example</h1>

        <div id="feedback"></div>

        <form class="form-horizontal" id="search-form">
            <div class="form-group form-group-lg">
                <label class="col-sm-2 control-label">Username</label>
                <div class="col-sm-10">
                    <input type="text" class="form-control" id="username"/>
                </div>
            </div>

            <div class="form-group">
                <div class="col-sm-offset-2 col-sm-10">
                    <button type="submit" id="bth-search"
                            class="btn btn-primary btn-lg">Search
                    </button>
                </div>
            </div>
        </form>

    </div>

</div>

<div class="container">
    <footer>
        <p>
            © <a href="http://www.mkyong.com">Mkyong.com</a> 2017
        </p>
    </footer>
</div>

<script type="text/javascript"
        src="webjars/jquery/2.2.4/jquery.min.js"></script>

<script type="text/javascript" src="js/main.js"></script>

</body>
</html>

4.2 Get HTML form, convert the search criteria into JSON format via JSON.stringify, and send POST request via jQuery.ajax

main.js

$(document).ready(function () {

    $("#search-form").submit(function (event) {

        //stop submit the form, we will post it manually.
        event.preventDefault();

        fire_ajax_submit();

    });

});

function fire_ajax_submit() {

    var search = {}
    search["username"] = $("#username").val();

    $("#btn-search").prop("disabled", true);

    $.ajax({
        type: "POST",
        contentType: "application/json",
        url: "/api/search",
        data: JSON.stringify(search),
        dataType: 'json',
        cache: false,
        timeout: 600000,
        success: function (data) {

            var json = "<h4>Ajax Response</h4><pre>"
                + JSON.stringify(data, null, 4) + "</pre>";
            $('#feedback').html(json);

            console.log("SUCCESS : ", data);
            $("#btn-search").prop("disabled", false);

        },
        error: function (e) {

            var json = "<h4>Ajax Response</h4><pre>"
                + e.responseText + "</pre>";
            $('#feedback').html(json);

            console.log("ERROR : ", e);
            $("#btn-search").prop("disabled", false);

        }
    });

}

Done.

5. DEMO

5.1 Start Spring Boot

Terminal

$ mvn spring-boot:run

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.1.RELEASE)

2017-02-03 14:56:36 DEBUG com.mkyong.SpringBootWebApplication - Running with Spring Boot v1.5.1.RELEASE, Spring v4.3.6.RELEASE
2017-02-03 14:56:36 INFO  com.mkyong.SpringBootWebApplication - No active profile set, falling back to default profiles: default
2017-02-03 14:56:39 INFO  com.mkyong.SpringBootWebApplication - Started SpringBootWebApplication in 2.828 seconds (JVM running for 3.295)

5.2 Access http://localhost:8080/

5.3 If username is empty!

5.4 If username is not found!

5.5 If username is found!

6. Download Source Code

Download – spring-boot-ajax-example.zip (10 KB)

References

  1. Spring IO – Building a RESTful Web Service
  2. MDN – JSON.stringify()
  3. Spring 4 MVC Ajax Hello World Example

About the Author

author image
mkyong
Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

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avatar
newest oldest most voted
Mike
Guest
Mike

Thanks. Really helpful.
PD: I messed aroung a little until I found out that the project had to be imported as a Maven Project.

anurag
Guest
anurag

Great example
this article clear everything.
thanks

Carol
Guest
Carol

Thank you sincerely. Very clear

Ravikant Pandey
Guest
Ravikant Pandey

The solution does not work.
It cannot find GET http://localhost:8080/scout24/display/webjars/jquery/2.2.4/jquery.min.js net::ERR_ABORTED
home:47 GET http://localhost:8080/scout24/display/js/main.js net::ERR_ABORTED

Someone
Guest
Someone

Double quote missing from src attribute of script element

Sergey
Guest
Sergey

Hi all! I’m trying to search some usernames and receiving HTTP 404 Not found main.js . What I can resolve this problem?

Vikneswaran Thangarasu
Guest
Vikneswaran Thangarasu

How ajax.html is called when we launch the server ?

Luke
Guest
Luke

If you download the source code there is another class called IndexController which does not appear on this page. I believe IndexController redirects the “/” extension to ajax(.html) when the page is loaded. I do not fully understand what is going on either, that is just my understanding after exploring the code.

nalaka
Guest
nalaka

As i understand , IndexController is the main controller(WebMVC Controller- the other one is rest controller which returns a text,xml or json response) which route all the request with the root url to the .html page with the name of ‘ajax'( the returning string).

Vishal Srivastava
Guest
Vishal Srivastava

Once the server is startup. it looks for IndexController which returns the ajax.html page. Once you enter the value in the text box and submit it main.js /api/search post ajax is called which lookup for SearchController as you will drill down and u will go to SearchController you will find that this is a RestController which has a method getSearchResultViaAjax with two params first one takes the input which is send through main.js and second one Errors Interface from Spring Validation part.
In between very Clear Explanation mkyong Thanks!!!

Luke
Guest
Luke

Why is this project build with Thymeleaf? It is never used.

pandasjw
Guest
pandasjw

now?Thymeleaf is very popular?

Luke
Guest
Luke

I know Thymeleaf is popular. However, it is not doing anything in this program, therefore I do not think it should be included as a dependency.

klepra
Guest
klepra

It is used to render ajax.html from index controller.

faisal arkan
Guest
faisal arkan

thanks!
this help me out