Automate attribute converter

src/main/java/run/halo/app/config/HaloConfiguration.java

@@ -10,6 +10,7 @@
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
@@ -19,6 +20,7 @@
 import run.halo.app.cache.AbstractStringCacheStore;
 import run.halo.app.cache.InMemoryCacheStore;
 import run.halo.app.cache.LevelCacheStore;
+import run.halo.app.config.attributeconverter.AttributeConverterAutoGenerateConfiguration;
 import run.halo.app.config.properties.HaloProperties;
 import run.halo.app.repository.base.BaseRepositoryImpl;
 import run.halo.app.utils.HttpClientUtils;
@@ -35,6 +37,7 @@
 @EnableConfigurationProperties(HaloProperties.class)
 @EnableJpaRepositories(basePackages = "run.halo.app.repository", repositoryBaseClass =
     BaseRepositoryImpl.class)
+@Import(AttributeConverterAutoGenerateConfiguration.class)
 public class HaloConfiguration {
 
     private final HaloProperties haloProperties;

src/main/java/run/halo/app/config/attributeconverter/AttributeConverterAutoGenerateConfiguration.java

@@ -0,0 +1,20 @@
+package run.halo.app.config.attributeconverter;
+
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.boot.autoconfigure.orm.jpa.EntityManagerFactoryBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+
+/**
+ * Jpa configuration.
+ *
+ * @author johnniang
+ */
+public class AttributeConverterAutoGenerateConfiguration {
+
+    @Bean
+    EntityManagerFactoryBuilderCustomizer entityManagerFactoryBuilderCustomizer(
+        ConfigurableListableBeanFactory factory) {
+        return builder -> builder.setPersistenceUnitPostProcessors(
+                new AutoGenerateConverterPersistenceUnitPostProcessor(factory));
+    }
+}

src/main/java/run/halo/app/config/attributeconverter/AttributeConverterAutoGenerator.java

@@ -0,0 +1,71 @@
+package run.halo.app.config.attributeconverter;
+
+import static net.bytebuddy.description.annotation.AnnotationDescription.Builder.ofType;
+import static net.bytebuddy.description.type.TypeDescription.Generic.Builder.parameterizedType;
+import static net.bytebuddy.implementation.FieldAccessor.ofField;
+import static net.bytebuddy.implementation.MethodDelegation.to;
+import static net.bytebuddy.matcher.ElementMatchers.isDefaultConstructor;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+
+import java.lang.reflect.Modifier;
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.NamingStrategy;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
+import net.bytebuddy.implementation.MethodCall;
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * Attribute converter auto generator.
+ *
+ * @author johnniang
+ */
+class AttributeConverterAutoGenerator {
+
+    /**
+     * Auto generation suffix.
+     */
+    public static final String AUTO_GENERATION_SUFFIX = "$AttributeConverterGeneratedByByteBuddy";
+
+    private final ClassLoader classLoader;
+
+    public AttributeConverterAutoGenerator(ClassLoader classLoader) {
+        this.classLoader = classLoader;
+    }
+
+    public <T> Class<?> generate(Class<T> clazz) {
+        try {
+            return new ByteBuddy()
+                .with(new NamingStrategy.AbstractBase() {
+                    @Override
+                    protected String name(TypeDescription superClass) {
+                        return clazz.getName() + AUTO_GENERATION_SUFFIX;
+                    }
+                })
+                .subclass(
+                    parameterizedType(AttributeConverter.class, clazz, Integer.class).build())
+                .annotateType(ofType(Converter.class).define("autoApply", true).build())
+                .constructor(isDefaultConstructor())
+                .intercept(MethodCall.invoke(Object.class.getDeclaredConstructor())
+                    .andThen(ofField("enumType").setsValue(clazz)))
+                .defineField("enumType", Class.class, Modifier.PRIVATE | Modifier.FINAL)
+                .method(named("convertToDatabaseColumn"))
+                .intercept(to(AttributeConverterInterceptor.class))
+                .method(named("convertToEntityAttribute"))
+                .intercept(to(AttributeConverterInterceptor.class))
+                .make()
+                .load(this.classLoader, ClassLoadingStrategy.Default.INJECTION.allowExistingTypes())
+                .getLoaded();
+        } catch (NoSuchMethodException e) {
+            // should never happen
+            throw new RuntimeException("Failed to get declared constructor.", e);
+        }
+    }
+
+    public static boolean isGeneratedByByteBuddy(String className) {
+        return StringUtils.endsWith(className, AUTO_GENERATION_SUFFIX);
+    }
+
+}

src/main/java/run/halo/app/config/attributeconverter/AttributeConverterInterceptor.java

@@ -0,0 +1,27 @@
+package run.halo.app.config.attributeconverter;
+
+import net.bytebuddy.implementation.bind.annotation.FieldValue;
+import net.bytebuddy.implementation.bind.annotation.RuntimeType;
+import run.halo.app.model.enums.ValueEnum;
+
+/**
+ * Attribute Converter Interceptor.
+ *
+ * @author johnniang
+ */
+public class AttributeConverterInterceptor {
+
+    private AttributeConverterInterceptor() {
+    }
+
+    @RuntimeType
+    public static <T extends Enum<T> & ValueEnum<V>, V> V convertToDatabaseColumn(T attribute) {
+        return attribute == null ? null : attribute.getValue();
+    }
+
+    @RuntimeType
+    public static <T extends Enum<T> & ValueEnum<V>, V> T convertToEntityAttribute(V dbData,
+        @FieldValue("enumType") Class<T> enumType) {
+        return dbData == null ? null : ValueEnum.valueToEnum(enumType, dbData);
+    }
+}

src/main/java/run/halo/app/config/attributeconverter/AutoGenerateConverterPersistenceUnitPostProcessor.java

@@ -0,0 +1,55 @@
+package run.halo.app.config.attributeconverter;
+
+import static java.util.stream.Collectors.toUnmodifiableSet;
+
+import java.util.Set;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
+import org.springframework.core.type.filter.AssignableTypeFilter;
+import org.springframework.orm.jpa.persistenceunit.MutablePersistenceUnitInfo;
+import org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor;
+import org.springframework.util.ClassUtils;
+import run.halo.app.model.enums.ValueEnum;
+import run.halo.app.model.properties.PropertyEnum;
+
+/**
+ * Attribute converter persistence unit post processor.
+ *
+ * @author johnniang
+ */
+class AutoGenerateConverterPersistenceUnitPostProcessor implements PersistenceUnitPostProcessor {
+
+    private static final String PACKAGE_TO_SCAN = "run.halo.app";
+
+    private final ConfigurableListableBeanFactory factory;
+
+    public AutoGenerateConverterPersistenceUnitPostProcessor(
+        ConfigurableListableBeanFactory factory) {
+        this.factory = factory;
+    }
+
+    @Override
+    public void postProcessPersistenceUnitInfo(MutablePersistenceUnitInfo pui) {
+        var generator = new AttributeConverterAutoGenerator(factory.getBeanClassLoader());
+
+        findValueEnumClasses()
+            .stream()
+            .map(generator::generate)
+            .map(Class::getName)
+            .forEach(pui::addManagedClassName);
+    }
+
+    private Set<Class<?>> findValueEnumClasses() {
+        var scanner = new ClassPathScanningCandidateComponentProvider(false);
+        // include ValueEnum class
+        scanner.addIncludeFilter(new AssignableTypeFilter(ValueEnum.class));
+        // exclude PropertyEnum class
+        scanner.addExcludeFilter(new AssignableTypeFilter(PropertyEnum.class));
+
+        return scanner.findCandidateComponents(PACKAGE_TO_SCAN)
+            .stream()
+            .filter(bd -> bd.getBeanClassName() != null)
+            .map(bd -> ClassUtils.resolveClassName(bd.getBeanClassName(), null))
+            .collect(toUnmodifiableSet());
+    }
+}

src/main/java/run/halo/app/model/entity/Journal.java

@@ -47,7 +47,7 @@ public class Journal extends BaseEntity {
     private Long likes;
 
     @Column(name = "type")
-    @ColumnDefault("1")
+    @ColumnDefault("0")
     private JournalType type;
 
     @Override

src/main/java/run/halo/app/model/enums/JournalType.java

@@ -10,12 +10,12 @@ public enum JournalType implements ValueEnum<Integer> {
     /**
      * Public type.
      */
-    PUBLIC(1),
+    PUBLIC(0),
 
     /**
      * Intimate type.
      */
-    INTIMATE(0);
+    INTIMATE(1);
 
     private final int value;
 

src/main/java/run/halo/app/model/enums/ValueEnum.java

@@ -11,6 +11,13 @@
  */
 public interface ValueEnum<T> {
 
+    /**
+     * Gets enum value.
+     *
+     * @return enum value
+     */
+    T getValue();
+
     /**
      * Converts value to corresponding enum.
      *
@@ -20,7 +27,7 @@ public interface ValueEnum<T> {
      * @param <E> enum generic
      * @return corresponding enum
      */
-    static <V, E extends ValueEnum<V>> E valueToEnum(Class<E> enumType, V value) {
+    static <V, E extends Enum<E> & ValueEnum<V>> E valueToEnum(Class<E> enumType, V value) {
         Assert.notNull(enumType, "enum type must not be null");
         Assert.notNull(value, "value must not be null");
         Assert.isTrue(enumType.isEnum(), "type must be an enum type");
@@ -30,12 +37,4 @@ static <V, E extends ValueEnum<V>> E valueToEnum(Class<E> enumType, V value) {
             .findFirst()
             .orElseThrow(() -> new IllegalArgumentException("unknown database value: " + value));
     }
-
-    /**
-     * Gets enum value.
-     *
-     * @return enum value
-     */
-    T getValue();
-
 }