feat: Add interfaces for CRUD services

vaadin-spring/pom.xml

@@ -43,6 +43,12 @@
             <artifactId>jakarta.servlet-api</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <version>1.0.0</version>
+        </dependency>
+
 
         <dependency>
             <groupId>com.vaadin</groupId>
@@ -97,6 +103,26 @@
             <artifactId>spring-data-commons</artifactId>
             <optional>true</optional>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.data</groupId>
+            <artifactId>spring-data-jpa</artifactId>
+            <scope>provided</scope>
+            <exclusions>
+                <exclusion>
+                    <artifactId>aspectjrt</artifactId>
+                    <groupId>org.aspectj</groupId>
+                </exclusion>
+                <exclusion>
+                    <artifactId>jcl-over-slf4j</artifactId>
+                    <groupId>org.slf4j</groupId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>jakarta.persistence</groupId>
+            <artifactId>jakarta.persistence-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>com.vaadin</groupId>
             <artifactId>flow-data</artifactId>
@@ -120,6 +146,22 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-test-autoconfigure</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+            <scope>test</scope>
+        </dependency>
+
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
@@ -189,13 +231,13 @@
 
     <dependencyManagement>
         <dependencies>
-	        <dependency>
-	            <groupId>org.springframework.boot</groupId>
-	            <artifactId>spring-boot-dependencies</artifactId>
-	            <version>${spring.boot.version}</version>
-	            <type>pom</type>
-	            <scope>import</scope>
-	        </dependency>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring.boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
         </dependencies>
     </dependencyManagement>
 </project>

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/CountService.java

@@ -0,0 +1,22 @@
+package com.vaadin.flow.spring.data;
+
+import org.jspecify.annotations.Nullable;
+
+import com.vaadin.flow.spring.data.filter.Filter;
+
+/**
+ * A service that can count the number of items with a given filter.
+ */
+public interface CountService {
+
+    /**
+     * Counts the number of items that match the given filter.
+     *
+     * @param filter
+     *            the filter, or {@code null} to use no filter
+     * @return
+     *           the number of items in the service that match the filter
+     */
+    public long count(@Nullable Filter filter);
+
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/CrudService.java

@@ -0,0 +1,12 @@
+package com.vaadin.flow.spring.data;
+
+/**
+ * A service that can create, read, update, and delete a given type of object.
+ * 
+ * @param <T>
+ *            the type of object to manage
+ * @param <ID>
+ *            the type of the object's identifier
+ */
+public interface CrudService<T, ID> extends ListService<T>, FormService<T, ID> {
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/FormService.java

@@ -0,0 +1,33 @@
+package com.vaadin.flow.spring.data;
+
+/**
+ * A service that can update and delete a given type of object.
+ * 
+ * @param <T>
+ *            the type of object to manage
+ * @param <ID>
+ *            the type of the object's identifier
+ * 
+ */
+public interface FormService<T, ID> {
+
+    /**
+     * Saves the given object and returns the (potentially) updated object.
+     * <p>
+     * If you store the object in a SQL database, the returned object might have
+     * a new id or updated consistency version.
+     *
+     * @param value
+     *            the object to save
+     * @return the fresh object; will never be {@literal null}.
+     */
+    T save(T value);
+
+    /**
+     * Deletes the object with the given id.
+     *
+     * @param id
+     *            the id of the object to delete
+     */
+    void delete(ID id);
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/GetService.java

@@ -0,0 +1,30 @@
+package com.vaadin.flow.spring.data;
+
+import java.util.Optional;
+
+/**
+ * A service that can fetch the given type of object.
+ */
+public interface GetService<T, ID> {
+
+    /**
+     * Gets the object with the given id.
+     *
+     * @param id
+     *            the id of the object
+     * @return the object, or an empty optional if no object with the given id
+     */
+    Optional<T> get(ID id);
+
+    /**
+     * Checks if an object with the given id exists.
+     *
+     * @param id
+     *            the id of the object
+     * @return {@code true} if the object exists, {@code false} otherwise
+     */
+    default boolean exists(ID id) {
+        return get(id).isPresent();
+    }
+
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/ListService.java

@@ -0,0 +1,29 @@
+package com.vaadin.flow.spring.data;
+
+import java.util.List;
+
+import org.jspecify.annotations.Nullable;
+import org.springframework.data.domain.Pageable;
+
+import com.vaadin.flow.spring.data.filter.Filter;
+
+/**
+ * A service that can list the given type of object.
+ * 
+ * @param <T>
+ *            the type of object to list
+ */
+public interface ListService<T> {
+    /**
+     * Lists objects of the given type using the paging, sorting and filtering
+     * options provided in the parameters.
+     *
+     * @param pageable
+     *            contains information about paging and sorting
+     * @param filter
+     *            the filter to apply or {@code null} to not filter
+     * @return a list of objects or an empty list if no objects were found
+     */
+    List<T> list(Pageable pageable, @Nullable Filter filter);
+
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/AndFilter.java

@@ -0,0 +1,45 @@
+package com.vaadin.flow.spring.data.filter;
+
+import java.util.List;
+
+/**
+ * A filter that requires all children to pass.
+ * <p>
+ * Custom filter implementations need to handle this filter by running all child
+ * filters and verifying that all of them pass.
+ */
+public class AndFilter extends Filter {
+
+    private List<Filter> children;
+
+    /**
+     * Create an empty filter.
+     */
+    public AndFilter() {
+        // Empty constructor is needed for serialization
+    }
+
+    /**
+     * Create a filter with the given children.
+     *
+     * @param children
+     *            the children of the filter
+     */
+    public AndFilter(Filter... children) {
+        setChildren(List.of(children));
+    }
+
+    public List<Filter> getChildren() {
+        return children;
+    }
+
+    public void setChildren(List<Filter> children) {
+        this.children = children;
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName() + " [children=" + children + "]";
+    }
+
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/Filter.java

@@ -0,0 +1,27 @@
+package com.vaadin.flow.spring.data.filter;
+
+import java.io.Serializable;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
+/**
+ * Superclass for all filters to be used with CRUD services. This specific class
+ * is never used, instead a filter instance will be one of the following types:
+ * <ul>
+ * <li>{@link AndFilter} - Contains a list of nested filters, all of which need
+ * to pass.</li>
+ * <li>{@link OrFilter} - Contains a list of nested filters, of which at least
+ * one needs to pass.</li>
+ * <li>{@link PropertyStringFilter} - Matches a specific property, or nested
+ * property path, against a filter value, using a specific operator.</li>
+ * </ul>
+ */
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY)
+@JsonSubTypes({ @Type(value = OrFilter.class, name = "or"),
+        @Type(value = AndFilter.class, name = "and"),
+        @Type(value = PropertyStringFilter.class, name = "propertyString") })
+public class Filter implements Serializable {
+
+}

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/OrFilter.java

@@ -0,0 +1,45 @@
+package com.vaadin.flow.spring.data.filter;
+
+import java.util.List;
+
+/**
+ * A filter that requires at least one of its children to pass.
+ * <p>
+ * Custom filter implementations need to handle this filter by running all child
+ * filters and verifying that at least one of them passes.
+ */
+public class OrFilter extends Filter {
+
+    private List<Filter> children;
+
+    /**
+     * Create an empty filter.
+     */
+    public OrFilter() {
+        // Empty constructor is needed for serialization
+    }
+
+    /**
+     * Create a filter with the given children.
+     *
+     * @param children
+     *            the children of the filter
+     */
+    public OrFilter(Filter... children) {
+        setChildren(List.of(children));
+    }
+
+    public List<Filter> getChildren() {
+        return children;
+    }
+
+    public void setChildren(List<Filter> children) {
+        this.children = children;
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName() + " [children=" + children + "]";
+    }
+
+}