Add json properties with hibernate UserType mapping to 'user' entity

benruehl
1 parent 201450f1
Showing 7 changed files with 161 additions and 10 deletions
services/Common/src/main/java/de/bht/beuthbot/model/entities/User.java
services/Global/build.gradle
services/Global/src/main/java/de/bht/beuthbot/entities/EntityBase.java
services/Global/src/main/java/de/bht/beuthbot/entities/User.java
services/Global/src/main/java/de/bht/beuthbot/persistence/JsonHelper.java
services/Global/src/main/java/de/bht/beuthbot/persistence/JsonMapUserType.java
services/Global/src/main/java/de/bht/beuthbot/persistence/UserManager.java
@@ -7,5 +7,6 @@ public interface User extends Entity {
  
     String getFacebookUserId();
     String getTelegramUserId();
-    boolean isVegetarian();
+    <T extends Object> T getProperty(String propertyName, Class<T> propertyType);
+    void setProperty(String propertyName, Object propertyValue);
 }
@@ -15,6 +15,7 @@ dependencies {
             "org.hibernate:hibernate-core:5.2.12.Final",
             "org.hibernate:hibernate-entitymanager:4.3.6.Final"
  
+    compile group: 'org.postgresql', name: 'postgresql', version: '9.3-1100-jdbc4'
  
     providedCompile "org.slf4j:slf4j-api:1.7.25"
  
 package de.bht.beuthbot.entities;
  
 import de.bht.beuthbot.model.entities.Entity;
+import de.bht.beuthbot.persistence.JsonMapUserType;
+import org.hibernate.annotations.TypeDef;
  
 import javax.persistence.*;
 import java.util.Date;
@@ -10,6 +12,8 @@ import java.util.Objects;
  * Created by Benjamin Rühl on 19.11.2017.
  */
 @MappedSuperclass
+@Access(AccessType.FIELD)
+@TypeDef(name = "JsonMapType", typeClass = JsonMapUserType.class)
 public class EntityBase implements Entity {
  
     @Id
@@ -63,7 +67,7 @@ public class EntityBase implements Entity {
         if (other.getId() == 0 && getId() == 0)
             return super.equals(obj);
  
-        return other.getId() == getId();
+        return Objects.equals(other.getId(), getId());
     }
  
     @Override
 package de.bht.beuthbot.entities;
  
+import de.bht.beuthbot.persistence.JsonHelper;
+import org.hibernate.annotations.Type;
+
 import javax.persistence.Entity;
 import javax.persistence.Table;
+import java.util.HashMap;
+import java.util.Map;
  
 /**
  * Created by Benjamin Rühl on 19.11.2017.
@@ -12,7 +17,9 @@ public class User extends EntityBase implements de.bht.beuthbot.model.entities.U
  
     private String facebookUserId;
     private String telegramUserId;
-    private boolean isVegetarian;
+
+    @Type(type = "JsonMapType")
+    private Map<String, String> additionalData = new HashMap<>();
  
     @Override
     public String getFacebookUserId() {
@@ -25,8 +32,19 @@ public class User extends EntityBase implements de.bht.beuthbot.model.entities.U
     }
  
     @Override
-    public boolean isVegetarian() {
-        return isVegetarian;
+    public <T extends Object> T getProperty(String propertyName, Class<T> propertyType) {
+        String propertyValue = additionalData.getOrDefault(propertyName, null);
+
+        if (propertyValue == null)
+            return null;
+
+        return (T) JsonHelper.fromJson(propertyValue, propertyType);
+    }
+
+    @Override
+    public void setProperty(String propertyName, Object propertyValue) {
+        String valueAsJson = JsonHelper.toJson(propertyValue, propertyValue.getClass());
+        additionalData.put(propertyName, valueAsJson);
     }
  
     public void setFacebookUserId(String facebookUserId) {
@@ -36,8 +54,4 @@ public class User extends EntityBase implements de.bht.beuthbot.model.entities.U
     public void setTelegramUserId(String telegramUserId) {
         this.telegramUserId = telegramUserId;
     }
-
-    public void setVegetarian(boolean vegetarian) {
-        this.isVegetarian = vegetarian;
-    }
 }
+package de.bht.beuthbot.persistence;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+/**
+ * Created by Benjamin Rühl on 03.12.2017.
+ * A simple wrapper around the json serializer to make sure the same serializer is used across different classes
+ */
+public class JsonHelper {
+
+    private static final Gson gson = new GsonBuilder().serializeNulls().create();
+
+    public static Object fromJson(String json, Class sourceClass) {
+        return gson.fromJson(json, sourceClass);
+    }
+
+    public static String toJson(Object source, Class sourceClass) {
+        return gson.toJson(source, sourceClass);
+    }
+}
+package de.bht.beuthbot.persistence;
+
+import org.hibernate.HibernateException;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.internal.util.compare.EqualsHelper;
+import org.hibernate.type.SerializationException;
+import org.hibernate.usertype.UserType;
+import org.postgresql.util.PGobject;
+
+import java.io.Serializable;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Types;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Created by Benjamin Rühl on 03.12.2017.
+ * Custom Hibernate UserType for mapping json typed columns in postgres to java maps
+ * @see <a href="http://vojtechruzicka.com/postgresqls-jsonb-type-mapping-using-hibernate/">vojtechruzicka.com</a>
+ */
+public class JsonMapUserType implements UserType {
+
+    @Override
+    public void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor session) throws HibernateException, SQLException {
+        if (value == null) {
+            st.setNull(index, Types.OTHER);
+        } else {
+            st.setObject(index, JsonHelper.toJson(value, Map.class), Types.OTHER);
+        }
+    }
+
+    @Override
+    public Object nullSafeGet(ResultSet rs, String[] names, SharedSessionContractImplementor session, Object owner) throws HibernateException, SQLException {
+        PGobject o = (PGobject) rs.getObject(names[0]);
+        if (o.getValue() != null) {
+            return JsonHelper.fromJson(o.getValue(), Map.class);
+        }
+
+        return new HashMap<String, String>();
+    }
+
+    @Override
+    public Object deepCopy(Object originalValue) throws HibernateException {
+        if (originalValue == null) {
+            return null;
+        }
+
+        if (!(originalValue instanceof Map)) {
+            return null;
+        }
+
+        Map<String, String> resultMap = new HashMap<>();
+
+        Map<?, ?> tempMap = (Map<?, ?>) originalValue;
+        tempMap.forEach((key, value) -> resultMap.put((String) key, (String) value));
+
+        return resultMap;
+    }
+
+    @Override
+    public Serializable disassemble(Object value) throws HibernateException {
+        Object copy = deepCopy(value);
+
+        if (copy instanceof Serializable) {
+            return (Serializable) copy;
+        }
+
+        throw new SerializationException(String.format("Cannot serialize '%s', %s is not Serializable.", value, value.getClass()), null);
+    }
+
+    @Override
+    public Object assemble(Serializable cached, Object owner) throws HibernateException {
+        return deepCopy(cached);
+    }
+
+    @Override
+    public Object replace(Object original, Object target, Object owner) throws HibernateException {
+        return deepCopy(original);
+    }
+
+    @Override
+    public boolean isMutable() {
+        return true;
+    }
+
+    @Override
+    public int hashCode(Object x) throws HibernateException {
+        if (x == null) {
+            return 0;
+        }
+
+        return x.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object x, Object y) throws HibernateException {
+        return EqualsHelper.equals(x, y);
+    }
+
+    @Override
+    public Class<?> returnedClass() {
+        return Map.class;
+    }
+
+    @Override
+    public int[] sqlTypes() {
+        return new int[]{Types.JAVA_OBJECT};
+    }
+}
@@ -16,7 +16,6 @@ public class UserManager {
         User user = new User();
         user.setFacebookUserId("FacebookUserId");
         user.setTelegramUserId("TelegramUserId");
-        user.setVegetarian(true);
  
         entityManager.persist(user);
     }