spring boot rest controller sample

gistfile1.txt

@RestController

@RequestMapping("/api")
public class ZipController {

    @PostMapping("/download-zip")
    public ResponseEntity<ByteArrayResource> downloadZip() throws IOException {
        // Create a ByteArrayOutputStream to hold the ZIP content
        String fileName = UUID.randomUUID().toString() + ".zip";
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try (ZipOutputStream zipOut = new ZipOutputStream(baos)) {
            // Add a README.md file to the ZIP
            addToZip(zipOut, "readme.md", "This is a sample README file.");

            // You can add more files if needed

            // Finish writing to the ZIP
            zipOut.finish();
        }

        // Set up HTTP headers
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        headers.setContentDispositionFormData("attachment", fileName);

        // Create a ByteArrayResource from the ZIP content
        ByteArrayResource resource = new ByteArrayResource(baos.toByteArray());

        // Return the ZIP file as a ByteArrayResource
        return ResponseEntity.ok()
                .headers(headers)
                .body(resource);
    }

    private void addToZip(ZipOutputStream zipOut, String fileName, String content) throws IOException {
        // Create a new ZIP entry
        zipOut.putNextEntry(new ZipEntry(fileName));

        // Write content to the ZIP entry
        zipOut.write(content.getBytes());

        // Close the ZIP entry
        zipOut.closeEntry();
    }
}

@Configuration
@EnableWebSecurity()
static class SecurityConfig {
    public static class CustomAuthenticationProvider implements AuthenticationProvider {
        private final String username;
        private final String password;
        private final String role;

        CustomAuthenticationProvider(String username, String password, String role) {
            this.username = username;
            this.password = password;
            this.role = role;
        }

        @Override
        public Authentication authenticate(Authentication auth)
                throws AuthenticationException {
            String u = auth.getName();
            String p = auth.getCredentials().toString();

            if (username.equals(u) && password.equals(p)) {
                return new UsernamePasswordAuthenticationToken
                        (username, password, Collections.singletonList(new SimpleGrantedAuthority(role)));
            } else {
                throw new
                        BadCredentialsException("External system authentication failed");
            }
        }

        @Override
        public boolean supports(Class<?> auth) {
            return auth.equals(UsernamePasswordAuthenticationToken.class);
        }
    }

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity httpSecurity) throws Exception {
        AuthenticationManagerBuilder authenticationManagerBuilder =
                httpSecurity.getSharedObject(AuthenticationManagerBuilder.class);

        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("user", "password", "USER"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("user1", "password", "USER"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("admin", "password", "ADMIN"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("admin1", "password", "ADMIN"));

        httpSecurity.authenticationManager(authenticationManagerBuilder.build());

        httpSecurity
                .authorizeHttpRequests(auth -> {
                    auth.requestMatchers(EndpointRequest.toAnyEndpoint()).permitAll();
                    auth.anyRequest().fullyAuthenticated();
                });
        httpSecurity.logout(new LogoutCustomizer());
        httpSecurity.formLogin(withDefaults());
        return httpSecurity.build();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return NoOpPasswordEncoder.getInstance();
    }
}



<!DOCTYPE html>
<html>

<head>
	<title>Secured</title>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<div class="container">
	<h1>Secured</h1>

	<form th:action="@{/logout}" method="post">
		<input id="logout" type="submit" value="Log Out"/>
	</form>

	<form id="downloadZip" th:action="@{/api/download-zip}" method="post">
		<input id="download" type="submit" value="Download"/>
	</form>
</div>
</body>
</html>



<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.0</version>
        <relativePath/>
    </parent>

    <properties>
        <java.version>17</java.version>
        <testcontainers.version>1.18.3</testcontainers.version>
        <jsonwebtoken.version>0.11.5</jsonwebtoken.version>
        <lombok.version>1.18.28</lombok.version>
        <springdoc.webstarter.ui.version>2.1.0</springdoc.webstarter.ui.version>
        <springdoc.openapi.ui.version>1.7.0</springdoc.openapi.ui.version>
        <kafka.clients.version>3.4.0</kafka.clients.version>
        <jacoco-plugin.version>0.8.8</jacoco-plugin.version>

        <sonar.jacoco.itReportPath>${project.build.outputDirectory}/coverage/jacoco/jacoco-it.exec</sonar.jacoco.itReportPath>
        <sonar.jacoco.reportPath>${project.build.outputDirectory}/coverage/jacoco/jacoco.exec</sonar.jacoco.reportPath>
        <sonar.java.codeCoveragePlugin>jacoco</sonar.java.codeCoveragePlugin>
        <sonar-maven-plugin.version>3.2</sonar-maven-plugin.version>
        <start-class>example.WebfluxFormApplication</start-class>
        <openapi-generator-maven-plugin.version>6.2.0</openapi-generator-maven-plugin.version>
    </properties>

    <dependencies>
        <!-- Spring Boot Starters -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
            <version>3.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.thymeleaf.extras</groupId>
            <artifactId>thymeleaf-extras-springsecurity6</artifactId>
        </dependency>

        <!-- Spring Boot Test Dependencies -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- Integration Test Dependencies -->
        <dependency>
            <groupId>org.seleniumhq.selenium</groupId>
            <artifactId>htmlunit-driver</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    

https://gist.github.com/Ikhiloya/d1d0d034c63199eed2c67a9a1a400152