【Spring MVC】Spring MVC で作成した API に String 配列を渡す

プロジェクト作成
構成
build.gradle
ソースコード
1. IndexController
2. SampleForm
Spring Boot 起動
ajax で String 配列を渡す
1. index.html
動作確認

プロジェクト作成

https://start.spring.io/ で Gradle Project を生成します。

Project: Gradle Project
Language: Java
Spring Boot: 2.6.1
Project Metadata
Group: com.example
- Artifact: demo
- Name: demo
- Description: Demo project for Spring Boot
- Package name: com.example.demo
Packaging: War
Java: 11
Dependencies:
- Spring Web
- Thymeleaf
- Lombok

構成

controller ディレクトリを作成します。
- Controller クラスをここに作成します。
form ディレクトリを作成します。
- Form クラスをここに作成します。

.
├── HELP.md
├── build
├── build.gradle
├── gradle
│  └── wrapper
│      ├── gradle-wrapper.jar
│      └── gradle-wrapper.properties
├── gradlew
├── gradlew.bat
├── settings.gradle
└── src
    ├── main
    │  ├── java
    │  │  └── com
    │  │      └── example
    │  │          └── demo
    │  │              ├── DemoApplication.java
    │  │              ├── ServletInitializer.java
    │  │              ├── controller
    │  │              │  └── IndexController.java
    │  │              └── form
    │  │                  └── SampleForm.java
    │  └── resources
    │      ├── application.properties
    │      ├── static
    │      └── templates
    └── test
        └── java
            └── com
                └── example
                    └── demo
                        └── DemoApplicationTests.java

build.gradle

Gradle のビルド設定ファイル

plugins {
    id 'org.springframework.boot' version '2.5.6'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
    id 'war'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'
    providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

test {
    useJUnitPlatform()
}

ソースコード

IndexController

/ でリクエストを受け付けます。
リクエストを SampleForm で受け取リます。
SampleForm#userIds に格納された userId を取り出しコンソールに表示します。

package com.example.demo.controller;

import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.validation.annotation.Validated;

import org.springframework.web.bind.annotation.CrossOrigin;

import com.example.demo.form.SampleForm;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@RestController
public class IndexController {
    @CrossOrigin
    @PostMapping("/")
    public String index(@Validated SampleForm sampleForm) {
        for(String userId : sampleForm.getUserIds()){
            System.out.println(userId);
        }
        return "success";
    }
}

SampleForm

String の配列をフィールドとして持たせます。

package com.example.demo.form;

import lombok.Data;

@Data
public class SampleForm {
    private String[] userIds;    
}

Spring Boot 起動

> gradle bootrun

> Task :bootRun

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.1)

2021-12-03 09:10:28.925  INFO 13648 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication using Java 11.0.11 on user-win with PID 13648 (D:\tmp\stringlistsample\build\classes\java\main started by user in D:\project\nexs\enurse\wiki\research\springmvc\src\stringlistsample)
2021-12-03 09:10:28.925  INFO 13648 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2021-12-03 09:10:29.798  INFO 13648 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2021-12-03 09:10:29.806  INFO 13648 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2021-12-03 09:10:29.806  INFO 13648 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.55]
2021-12-03 09:10:29.843  INFO 13648 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-12-03 09:10:29.843  INFO 13648 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 875 ms
2021-12-03 09:10:30.041  INFO 13648 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-12-03 09:10:30.058  INFO 13648 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 1.393 seconds (JVM running for 1.677)
2021-12-03 09:10:31.998  INFO 13648 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-12-03 09:10:31.999  INFO 13648 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2021-12-03 09:10:31.999  INFO 13648 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 0 ms
<==========---> 80% EXECUTING [2m 15s]
> :bootRun

ajax で String 配列を渡す

index.html

Spring MVC 側で SampleForm#userIds を String[] で定義しているので { ‘userIds’: [ ‘a’, ‘b’, ‘c’ ] } のように ajax で送ります。

<html>
    <head>
        <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
        <script>
            $.ajax({
                url: 'http://localhost:8080',
                type: 'POST',
                data: {
                    'userIds': [
                        '6743DAC2-CBF8-4652-A355-70A843215FEC',
                        '07B58F19-1876-4A09-9048-B361E8BFC47C',
                        '70DF334F-B058-4954-A509-F11A35B07174',
                        '9E814088-9994-4875-A668-3B418AF9BF1A',
                        'FD6A40B3-746A-4851-8675-525D78077DC7',
                        'A301EA10-E4D2-49B0-9163-D0E789C1A072',
                        '0F25AA62-3144-4965-9A59-94226EC59213',
                        '8F7A41D0-2FA0-457A-90A9-297A03AB6775',
                        '3D7A242B-0E8A-4539-AEFE-9081955C27E2',
                        '2163362D-FD4E-4CCB-865E-68B7B0E62464'
                    ]
                }
            }).done(function(data){
                $('#target').text(data);
            });
        </script>
    </head>
    <body>
        <span id="target"></span>
    </body>
</html>

動作確認

index.html を Web ブラウザで表示します。と画面に success と表示されます。

Spring MVC を起動しているコンソールには userId が表示されます。

6743DAC2-CBF8-4652-A355-70A843215FEC
07B58F19-1876-4A09-9048-B361E8BFC47C
70DF334F-B058-4954-A509-F11A35B07174
9E814088-9994-4875-A668-3B418AF9BF1A
FD6A40B3-746A-4851-8675-525D78077DC7
A301EA10-E4D2-49B0-9163-D0E789C1A072
0F25AA62-3144-4965-9A59-94226EC59213
8F7A41D0-2FA0-457A-90A9-297A03AB6775
3D7A242B-0E8A-4539-AEFE-9081955C27E2
2163362D-FD4E-4CCB-865E-68B7B0E62464