Added route for serving images from known disk location

pom.xml

@@ -34,6 +34,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-validation</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.module</groupId>
 			<artifactId>jackson-module-kotlin</artifactId>

src/main/kotlin/uk/co/neviyn/booru/ConfigurationProperty.kt

@@ -0,0 +1,42 @@
+package uk.co.neviyn.booru
+
+import com.sun.istack.NotNull
+import org.springframework.boot.context.properties.ConfigurationProperties
+import org.springframework.context.annotation.Configuration
+import org.springframework.validation.annotation.Validated
+import java.io.File
+import javax.validation.Constraint
+import javax.validation.ConstraintValidator
+import javax.validation.ConstraintValidatorContext
+import javax.validation.Payload
+import javax.validation.constraints.NotEmpty
+import kotlin.reflect.KClass
+
+
+@Configuration
+@ConfigurationProperties(prefix = "images")
+@Validated
+class ImageConfigurationProperties {
+    @NotNull
+    @IsValidDirectory
+    var directory: File = File("")
+
+    @NotEmpty
+    var types: List<String> = listOf("png", "jpg")
+}
+
+class DirectoryValidator : ConstraintValidator<IsValidDirectory, File> {
+    override fun isValid(value: File?, context: ConstraintValidatorContext?): Boolean {
+        if (value == null) return false
+        return value.exists() && value.isDirectory && value.canRead() && value.canWrite()
+    }
+}
+
+@MustBeDocumented
+@Constraint(validatedBy = [DirectoryValidator::class])
+@Target(AnnotationTarget.FIELD)
+annotation class IsValidDirectory(
+    val message: String = "Invalid image directory",
+    val groups: Array<KClass<*>> = [],
+    val payload: Array<KClass<out Payload>> = []
+)

src/main/kotlin/uk/co/neviyn/booru/StaticResource.kt

@@ -0,0 +1,17 @@
+package uk.co.neviyn.booru
+
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.context.annotation.Configuration
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer
+
+@Configuration
+class StaticResourceConfiguration @Autowired constructor(val imageConfigurationProperties: ImageConfigurationProperties) : WebMvcConfigurer {
+    override fun addResourceHandlers(registry: ResourceHandlerRegistry) {
+        // Mapping of /i endpoint to folder on disk that contains images
+        registry
+            .addResourceHandler(*(imageConfigurationProperties.types.map { "/i/*.$it" }.toTypedArray()))
+            .addResourceLocations(imageConfigurationProperties.directory.toURI().toString())
+        super.addResourceHandlers(registry)
+    }
+}

src/main/resources/application.properties

@@ -1,3 +1,4 @@
 spring.jpa.hibernate.ddl-auto=none
 spring.datasource.initialization-mode=always
 spring.jpa.properties.hibernate.default_schema=booru
+images.types=jpg,png,gif

src/test/resources/application.properties

@@ -2,4 +2,5 @@ spring.datasource.url=jdbc:h2:mem:testdb
 spring.datasource.driverClassName=org.h2.Driver
 spring.flyway.enabled=false
 spring.jpa.hibernate.ddl-auto=update
-spring.jpa.properties.hibernate.default_schema=booru
+spring.jpa.properties.hibernate.default_schema=
+images.directory=./images