#696 - ENH: Add fallback for @DbHstore ... fallback to JSON storage in VARCHAR

src/main/java/com/avaje/ebean/annotation/DbHstore.java

@@ -23,4 +23,8 @@ import java.lang.annotation.Target;
 @Target(ElementType.FIELD)
 public @interface DbHstore {
 
+  /**
+   * For VARCHAR storage specify the column length (defaults to 1000).
+   */
+  int length() default 0;
 }

src/main/java/com/avaje/ebeaninternal/server/deploy/parse/AnnotationFields.java

@@ -175,8 +175,9 @@ public class AnnotationFields extends AnnotationParser {
     if (comment != null) {
       prop.setDbComment(comment.value());
     }
-    if (get(prop, DbHstore.class) != null) {
-      util.setDbHstore(prop);
+    DbHstore dbHstore = get(prop, DbHstore.class);
+    if (dbHstore != null) {
+      util.setDbHstore(prop, dbHstore);
     }
     DbJson dbJson = get(prop, DbJson.class);
     if (dbJson != null) {

src/main/java/com/avaje/ebeaninternal/server/deploy/parse/DeployUtil.java

@@ -6,6 +6,7 @@ import javax.persistence.Enumerated;
 import javax.persistence.PersistenceException;
 
 import com.avaje.ebean.annotation.DbArray;
+import com.avaje.ebean.annotation.DbHstore;
 import com.avaje.ebean.annotation.DbJson;
 import com.avaje.ebean.annotation.DbJsonB;
 import com.avaje.ebean.annotation.DbJsonType;
@@ -203,15 +204,20 @@ public class DeployUtil {
   }
 
   /**
-   * Map to Postgres HSTORE type.
+   * Map to Postgres HSTORE type (with fallback to JSON storage in VARCHAR).
    */
-  public void setDbHstore(DeployBeanProperty prop) {
-    ScalarType<?> scalarType = typeManager.getScalarType(DbType.HSTORE);
-    if (scalarType == null) {
-      throw new RuntimeException("No ScalarType found for HSTORE on [" + prop.getFullBeanName() + "] ?");
-    }
-    prop.setDbType(DbType.HSTORE);
+  public void setDbHstore(DeployBeanProperty prop, DbHstore dbHstore) {
+
+    ScalarType<?> scalarType = typeManager.getHstoreScalarType();
+    int dbType = scalarType.getJdbcType();
+    prop.setDbType(dbType);
     prop.setScalarType(scalarType);
+    if (dbType == Types.VARCHAR) {
+      // this is actually the fallback of JSON storage into VARCHAR
+      int dbLength = dbHstore.length();
+      int columnLength = (dbLength > 0) ? dbLength : DEFAULT_JSON_VARCHAR_LENGTH;
+      prop.setDbLength(columnLength);
+    }
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/type/DefaultTypeManager.java

@@ -90,6 +90,8 @@ public final class DefaultTypeManager implements TypeManager, KnownImmutable {
 
   private final DefaultTypeFactory extraTypeFactory;
 
+  private final ScalarType<?> hstoreType = new ScalarTypePostgresHstore();
+
   private final ScalarTypeFile fileType = new ScalarTypeFile();
 
   private final ScalarType<?> charType = new ScalarTypeChar();
@@ -359,6 +361,11 @@ public final class DefaultTypeManager implements TypeManager, KnownImmutable {
     return reader;
   }
 
+  @Override
+  public ScalarType<?> getHstoreScalarType() {
+    return (postgres) ? hstoreType : ScalarTypeJsonMap.typeFor(false, Types.VARCHAR);
+  }
+
   @Override
   public ScalarType<?> getArrayScalarType(Class<?> type, DbArray dbArray, Type genericType) {
 
@@ -930,7 +937,7 @@ public final class DefaultTypeManager implements TypeManager, KnownImmutable {
     int platformClobType = databasePlatform.getClobDbType();
     int platformBlobType = databasePlatform.getBlobDbType();
 
-    nativeMap.put(DbType.HSTORE, new ScalarTypePostgresHstore());
+    nativeMap.put(DbType.HSTORE, hstoreType);
 
     ScalarType<?> utilDateType = extraTypeFactory.createUtilDate(mode);
     typeMap.put(java.util.Date.class, utilDateType);

src/main/java/com/avaje/ebeaninternal/server/type/TypeManager.java

@@ -72,4 +72,9 @@ public interface TypeManager {
    * Return the ScalarType used to handle DB ARRAY.
    */
   ScalarType<?> getArrayScalarType(Class<?> type, DbArray dbArray, Type genericType);
+
+  /**
+   * Return the ScalarType used to handle HSTORE (Map<String,String>).
+   */
+  ScalarType<?> getHstoreScalarType();
 }

src/test/java/com/avaje/tests/model/json/EBasicHstore.java

@@ -0,0 +1,62 @@
+package com.avaje.tests.model.json;
+
+import com.avaje.ebean.annotation.DbHstore;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Version;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+@Entity
+public class EBasicHstore {
+
+  @Id
+  Long id;
+
+  String name;
+
+  // fallback to varchar(800) for non-Postgres
+  @DbHstore(length = 800)
+  Map<String,String> map;
+
+  @Version
+  Long version;
+
+  public EBasicHstore(String name) {
+    this.name = name;
+    this.map = new LinkedHashMap<String, String>();
+  }
+
+  public Long getId() {
+    return id;
+  }
+
+  public void setId(Long id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public Map<String, String> getMap() {
+    return map;
+  }
+
+  public void setMap(Map<String, String> map) {
+    this.map = map;
+  }
+
+  public Long getVersion() {
+    return version;
+  }
+
+  public void setVersion(Long version) {
+    this.version = version;
+  }
+}

src/test/java/com/avaje/tests/types/TestHstore.java

@@ -0,0 +1,83 @@
+package com.avaje.tests.types;
+
+import com.avaje.ebean.BaseTestCase;
+import com.avaje.ebean.Ebean;
+import com.avaje.tests.model.json.EBasicHstore;
+import org.assertj.core.api.Assertions;
+import org.avaje.ebeantest.LoggedSqlCollector;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.StrictAssertions.assertThat;
+import static org.junit.Assert.assertEquals;
+
+public class TestHstore extends BaseTestCase {
+
+  private EBasicHstore bean;
+
+  @Test
+  public void insert() {
+
+    if (isPostgres()) {
+      // run this manually for Postgres with the HSTORE extension installed
+      // psql mydb -c 'create extension hstore;'
+      return;
+    }
+
+    bean = new EBasicHstore("one");
+    bean.getMap().put("home", "123");
+    bean.getMap().put("work", "987");
+
+    Ebean.save(bean);
+
+    json_parse_format();
+    update_when_notDirty();
+    update_when_dirty();
+    insert_when_null();
+  }
+
+  void json_parse_format() {
+
+    String asJson = Ebean.json().toJson(bean);
+    assertThat(asJson).contains("\"map\":{\"home\":\"123\",\"work\":\"987\"}");
+
+    EBasicHstore fromJson = Ebean.json().toBean(EBasicHstore.class, asJson);
+    assertEquals(bean.getId(), fromJson.getId());
+    assertEquals(bean.getName(), fromJson.getName());
+    Assertions.assertThat(fromJson.getMap().keySet()).containsExactly("home", "work");
+  }
+
+  void update_when_notDirty() {
+
+    EBasicHstore found = Ebean.find(EBasicHstore.class, bean.getId());
+    found.setName("modName");
+
+    LoggedSqlCollector.start();
+    Ebean.save(found);
+    List<String> sql = LoggedSqlCollector.stop();
+
+    // we don't update the map as it is not dirty
+    assertThat(sql.get(0)).contains("update ebasic_hstore set name=?, version=? where");
+  }
+
+  void update_when_dirty() {
+
+    EBasicHstore found = Ebean.find(EBasicHstore.class, bean.getId());
+    found.setName("modNamePlus");
+    found.getMap().put("foo","9987");
+
+    LoggedSqlCollector.start();
+    Ebean.save(found);
+    List<String> sql = LoggedSqlCollector.stop();
+
+    assertThat(sql.get(0)).contains("update ebasic_hstore set name=?, map=?, version=? where id=? and version=?");
+  }
+
+  void insert_when_null() {
+
+    EBasicHstore bean = new EBasicHstore("one");
+    bean.setMap(null);
+    Ebean.save(bean);
+  }
+}