#477 - findUnique() should throw NonUniqueResultException and not PersistenceException

src/main/java/com/avaje/ebean/EbeanServer.java

@@ -9,6 +9,7 @@ import com.avaje.ebean.text.csv.CsvReader;
 import com.avaje.ebean.text.json.JsonContext;
 import org.jetbrains.annotations.Nullable;
 
+import javax.persistence.NonUniqueResultException;
 import javax.persistence.OptimisticLockException;
 import javax.persistence.PersistenceException;
 import java.util.Collection;
@@ -1091,14 +1092,17 @@ public interface EbeanServer {
   <T> Map<?, T> findMap(Query<T> query, Transaction transaction);
 
   /**
-   * Execute the query returning at most one entity bean. This will throw a
-   * PersistenceException if the query finds more than one result.
+   * Execute the query returning at most one entity bean or null (if no matching
+   * bean is found).
+   * <p>
+   * This will throw a NonUniqueResultException if the query finds more than one result.
+   * </p>
    * <p>
    * Generally you are able to use {@link Query#findUnique()} rather than
    * explicitly calling this method. You could use this method if you wish to
    * explicitly control the transaction used for the query.
    * </p>
-   * 
+   *
    * @param <T>
    *          the type of entity bean to fetch.
    * @param query
@@ -1106,6 +1110,7 @@ public interface EbeanServer {
    * @param transaction
    *          the transaction to use (can be null).
    * @return the list of fetched beans.
+   * @throws NonUniqueResultException if more than one result was found
    *
    * @see Query#findUnique()
    */

src/main/java/com/avaje/ebean/ExpressionList.java

@@ -3,6 +3,7 @@ package com.avaje.ebean;
 import com.avaje.ebean.text.PathProperties;
 import org.jetbrains.annotations.Nullable;
 
+import javax.persistence.NonUniqueResultException;
 import java.io.Serializable;
 import java.sql.Timestamp;
 import java.util.Collection;
@@ -193,8 +194,15 @@ public interface ExpressionList<T> extends Serializable {
   <K> Map<K, T> findMap(String keyProperty, Class<K> keyType);
 
   /**
-   * Execute the query returning a single bean.
-   * 
+   * Execute the query returning a single bean or null (if no matching
+   * bean is found).
+   * <p>
+   * If more than 1 row is found for this query then a NonUniqueResultException is
+   * thrown.
+   * </p>
+   *
+   * @throws NonUniqueResultException if more than one result was found
+   *
    * @see Query#findUnique()
    */
   @Nullable

src/main/java/com/avaje/ebean/Query.java

@@ -3,6 +3,7 @@ package com.avaje.ebean;
 import com.avaje.ebean.text.PathProperties;
 import org.jetbrains.annotations.Nullable;
 
+import javax.persistence.NonUniqueResultException;
 import java.io.Serializable;
 import java.sql.Timestamp;
 import java.util.List;
@@ -700,7 +701,7 @@ public interface Query<T> extends Serializable {
    * Execute the query returning either a single bean or null (if no matching
    * bean is found).
    * <p>
-   * If more than 1 row is found for this query then a PersistenceException is
+   * If more than 1 row is found for this query then a NonUniqueResultException is
    * thrown.
    * </p>
    * <p>
@@ -736,6 +737,8 @@ public interface Query<T> extends Serializable {
    * List<OrderDetail> details = order.getDetails();
    * ...
    * }</pre>
+   *
+   * @throws NonUniqueResultException if more than one result was found
    */
   @Nullable
   T findUnique();

src/main/java/com/avaje/ebeaninternal/server/core/DefaultServer.java

@@ -70,6 +70,7 @@ import com.avaje.ebeaninternal.util.ParamTypeHelper.TypeInfo;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.persistence.NonUniqueResultException;
 import javax.persistence.OptimisticLockException;
 import javax.persistence.PersistenceException;
 import java.util.ArrayList;
@@ -1218,13 +1219,16 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
 
     // a query that is expected to return either 0 or 1 rows
     List<T> list = findList(query, t);
+    return extractUnique(list);
+  }
 
-    if (list.size() == 0) {
+  private <T> T extractUnique(List<T> list) {
+    if (list.isEmpty()) {
       return null;
-      
+
     } else if (list.size() > 1) {
-      throw new PersistenceException("Unique expecting 0 or 1 rows but got [" + list.size() + "]");
-      
+      throw new NonUniqueResultException("Unique expecting 0 or 1 results but got [" + list.size() + "]");
+
     } else {
       return list.get(0);
     }
@@ -1449,17 +1453,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
     // no findId() method for SqlQuery...
     // a query that is expected to return either 0 or 1 rows
     List<SqlRow> list = findList(query, t);
-
-    if (list.size() == 0) {
-      return null;
-
-    } else if (list.size() > 1) {
-      String m = "Unique expecting 0 or 1 rows but got [" + list.size() + "]";
-      throw new PersistenceException(m);
-
-    } else {
-      return list.get(0);
-    }
+    return extractUnique(list);
   }
 
   public SqlFutureList findFutureList(SqlQuery query, Transaction t) {