Initial version of FS attachment feature

cds-feature-attachments/pom.xml

@@ -79,13 +79,11 @@
         <dependency>
             <groupId>ch.qos.logback</groupId>
             <artifactId>logback-classic</artifactId>
-            <version>1.5.12</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.awaitility</groupId>
             <artifactId>awaitility</artifactId>
-            <version>4.2.2</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

examples/cds-feature-attachments-fs/README.md

@@ -0,0 +1,7 @@
+### General Info
+
+This artifact demonstrates how to implement a custom storage for the cds-feature-attachments. This is just a sample implementation using a filessystem as content storage. It's not supposed for productive usage.
+
+### Implementation details
+
+This artifact provides a custom handlers for events from the [AttachmentService](../cds-feature-attachments/src/main/java/com/sap/cds/feature/attachments/service/AttachmentService.java).

examples/cds-feature-attachments-fs/pom.xml

@@ -0,0 +1,74 @@
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
+    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>
+
+    <parent>
+        <groupId>com.sap.cds</groupId>
+        <artifactId>cds-feature-attachments-root</artifactId>
+        <version>${revision}</version>
+        <relativePath>../..</relativePath>
+    </parent>
+
+    <artifactId>cds-feature-attachments-fs</artifactId>
+    <packaging>jar</packaging>
+
+    <name>CDS Feature for Attachments - Filesystem</name>
+    <url>https://cap.cloud.sap/docs/plugins/#attachments</url>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.sap.cds</groupId>
+            <artifactId>cds-feature-attachments</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>com.sap.cds</groupId>
+            <artifactId>cds-services-api</artifactId>
+        </dependency>
+
+        <!-- TESTS -->
+        <dependency>
+            <groupId>com.sap.cds</groupId>
+            <artifactId>cds-services-impl</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+
+            <plugin>
+                <groupId>com.sap.cds</groupId>
+                <artifactId>cds-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>cds.resolve</id>
+                        <goals>
+                            <goal>resolve</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>com.github.spotbugs</groupId>
+                <artifactId>spotbugs-maven-plugin</artifactId>
+                <configuration>
+                    <skip>true</skip>
+                </configuration>
+            </plugin>
+
+        </plugins>
+    </build>
+
+</project>

examples/cds-feature-attachments-fs/src/main/java/com/sap/cds/feature/attachments/fs/configuration/Registration.java

@@ -0,0 +1,32 @@
+package com.sap.cds.feature.attachments.fs.configuration;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+import org.apache.commons.io.FileUtils;
+
+import com.sap.cds.feature.attachments.fs.handler.FSApplicationServiceHandler;
+import com.sap.cds.feature.attachments.fs.handler.FSAttachmentsServiceHandler;
+import com.sap.cds.services.runtime.CdsRuntimeConfiguration;
+import com.sap.cds.services.runtime.CdsRuntimeConfigurer;
+
+/**
+ * The class registers the event handlers for the attachments feature based on filesystem.
+ */
+public class Registration implements CdsRuntimeConfiguration {
+
+	@Override
+	public void eventHandlers(CdsRuntimeConfigurer configurer) {
+		configurer.eventHandler(new FSApplicationServiceHandler());
+
+		Path tmpPath = FileUtils.getTempDirectory().toPath();
+		Path rootFolder = tmpPath.resolve("com.sap.cds.cds-feature-attachments-fs");
+
+		try {
+			configurer.eventHandler(new FSAttachmentsServiceHandler(rootFolder));
+		} catch (IOException e) {
+			throw new IllegalStateException("Error while creating the FSAttachmentsServiceHandler", e);
+		}
+	}
+
+}

examples/cds-feature-attachments-fs/src/main/java/com/sap/cds/feature/attachments/fs/handler/FSApplicationServiceHandler.java

@@ -0,0 +1,41 @@
+package com.sap.cds.feature.attachments.fs.handler;
+
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.sap.cds.CdsData;
+import com.sap.cds.services.cds.ApplicationService;
+import com.sap.cds.services.cds.CdsCreateEventContext;
+import com.sap.cds.services.cds.CdsUpdateEventContext;
+import com.sap.cds.services.draft.DraftCreateEventContext;
+import com.sap.cds.services.handler.EventHandler;
+import com.sap.cds.services.handler.annotations.Before;
+import com.sap.cds.services.handler.annotations.HandlerOrder;
+import com.sap.cds.services.handler.annotations.ServiceName;
+import com.sap.cds.services.utils.OrderConstants;
+
+@ServiceName(value = "*", type = ApplicationService.class)
+public class FSApplicationServiceHandler implements EventHandler {
+
+	private static final Logger logger = LoggerFactory.getLogger(FSApplicationServiceHandler.class);
+
+	@Before
+	public void processBeforeNewDraft(DraftCreateEventContext context, List<CdsData> data) {
+		logger.info("Creating new draft for entity {}", context.getTarget());
+	}
+
+	@Before
+	@HandlerOrder(OrderConstants.Before.CHECK_CAPABILITIES + 1)
+	public void processCreateAttachments(CdsCreateEventContext context, List<CdsData> data) {
+		// TODO: add real implementation
+	}
+
+	@Before
+	@HandlerOrder(OrderConstants.Before.CHECK_CAPABILITIES + 1)
+	public void processUpdateAttachments(CdsUpdateEventContext context, List<CdsData> data) {
+		// TODO: add real implementation
+	}
+
+}

examples/cds-feature-attachments-fs/src/main/java/com/sap/cds/feature/attachments/fs/handler/FSAttachmentsServiceHandler.java

@@ -0,0 +1,111 @@
+/**************************************************************************
+ * (C) 2019-2024 SAP SE or an SAP affiliate company. All rights reserved. *
+ **************************************************************************/
+package com.sap.cds.feature.attachments.fs.handler;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.apache.commons.io.FileUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.sap.cds.feature.attachments.generated.cds4j.sap.attachments.Attachments;
+import com.sap.cds.feature.attachments.generated.cds4j.sap.attachments.MediaData;
+import com.sap.cds.feature.attachments.generated.cds4j.sap.attachments.StatusCode;
+import com.sap.cds.feature.attachments.service.AttachmentService;
+import com.sap.cds.feature.attachments.service.model.servicehandler.AttachmentCreateEventContext;
+import com.sap.cds.feature.attachments.service.model.servicehandler.AttachmentMarkAsDeletedEventContext;
+import com.sap.cds.feature.attachments.service.model.servicehandler.AttachmentReadEventContext;
+import com.sap.cds.feature.attachments.service.model.servicehandler.AttachmentRestoreEventContext;
+import com.sap.cds.services.EventContext;
+import com.sap.cds.services.handler.EventHandler;
+import com.sap.cds.services.handler.annotations.On;
+import com.sap.cds.services.handler.annotations.ServiceName;
+
+/**
+ * This class is an event handler that is called when an attachment is created, marked as deleted, restored or read.
+ */
+@ServiceName(value = "*", type = AttachmentService.class)
+public class FSAttachmentsServiceHandler implements EventHandler {
+
+	private static final Logger logger = LoggerFactory.getLogger(FSAttachmentsServiceHandler.class);
+
+	private final Path rootFolder;
+
+	public FSAttachmentsServiceHandler(Path rootFolder) throws IOException {
+		this.rootFolder = rootFolder;
+		if (!Files.exists(this.rootFolder)) {
+			Files.createDirectories(this.rootFolder);
+		}
+	}
+
+	@On
+	public void createAttachment(AttachmentCreateEventContext context) throws IOException {
+		logger.info("FS Attachment Service handler called for creating attachment for entity name: {}",
+				context.getAttachmentEntity().getQualifiedName());
+		String contentId = (String) context.getAttachmentIds().get(Attachments.ID);
+
+		MediaData data = context.getData();
+		data.setStatus(StatusCode.CLEAN);
+
+		try (InputStream input = data.getContent()) {
+			Path contentPath = getContentPath(context, contentId);
+			Files.createDirectories(contentPath.getParent());
+			Files.copy(input, contentPath);
+
+			context.setIsInternalStored(false);
+			context.setContentId(contentId);
+			context.setCompleted();
+		}
+	}
+
+	@On
+	public void markAttachmentAsDeleted(AttachmentMarkAsDeletedEventContext context) throws IOException {
+		logger.info("Marking attachment as deleted with document id: {}", context.getContentId());
+
+		Path contenPath = getContentPath(context, context.getContentId());
+		Path parent = contenPath.getParent();
+		Path destPath = getDeletedFolder(context).resolve(parent.getFileName());
+
+		FileUtils.moveDirectory(parent.toFile(), destPath.toFile());
+		context.setCompleted();
+	}
+
+	@On
+	public void restoreAttachment(AttachmentRestoreEventContext context) {
+		logger.info("FS Attachment Service handler called for restoring attachment for timestamp: {}",
+				context.getRestoreTimestamp());
+
+		// nothing to do as data are stored in the database and handled by the database
+		context.setCompleted();
+	}
+
+	@On
+	public void readAttachment(AttachmentReadEventContext context) throws IOException {
+		logger.info("FS Attachment Service handler called for reading attachment with document id: {}",
+				context.getContentId());
+		InputStream fileInputStream = Files.newInputStream(getContentPath(context, context.getContentId()));
+		context.getData().setContent(fileInputStream);
+		context.setCompleted();
+	}
+
+	private Path getContentPath(EventContext context, String contentId) {
+		return this.rootFolder.resolve("%s/%s/content.bin".formatted(getTenant(context), contentId));
+	}
+
+	private Path getDeletedFolder(EventContext context) {
+		return this.rootFolder.resolve("%s/deleted".formatted(getTenant(context)));
+	}
+
+	private static String getTenant(EventContext context) {
+		String tenant = context.getUserInfo().getTenant();
+		if (tenant == null) {
+			tenant = "default";
+		}
+		return tenant;
+	}
+
+}

examples/cds-feature-attachments-fs/src/main/resources/META-INF/services/com.sap.cds.services.runtime.CdsRuntimeConfiguration

@@ -0,0 +1 @@
+com.sap.cds.feature.attachments.fs.configuration.Registration

pom.xml

@@ -46,6 +46,7 @@
 
     <modules>
         <module>cds-feature-attachments</module>
+        <module>examples/cds-feature-attachments-fs</module>
         <module>integration-tests</module>
     </modules>
 
@@ -75,6 +76,20 @@
                 <scope>import</scope>
             </dependency>
 
+            <dependency>
+                <groupId>org.awaitility</groupId>
+                <artifactId>awaitility</artifactId>
+                <version>4.2.2</version>
+                <scope>test</scope>
+            </dependency>
+
+            <dependency>
+                <groupId>ch.qos.logback</groupId>
+                <artifactId>logback-classic</artifactId>
+                <version>1.5.9</version>
+                <scope>test</scope>
+            </dependency>
+
             <dependency>
                 <groupId>com.sap.cds</groupId>
                 <artifactId>cds-feature-attachments</artifactId>