From 32ac52db75f6943ee195a50089df5d8462cddfa4 Mon Sep 17 00:00:00 2001
From: mrbatista <mrba7ista@gmail.com>
Date: Tue, 31 Mar 2015 11:32:50 +0200
Subject: [PATCH] Added method `getUniqueResult()` in class `CursorEntity`.
 This method return `Object` if result of AQL query return one element. Throw
 `NonUniqueResultException` if call method and size is greater than one.

---
 .../arangodb/NonUniqueResultException.java    | 15 ++++++
 .../com/arangodb/entity/CursorEntity.java     |  8 +++
 .../com/arangodb/ArangoDriverCursorTest.java  | 51 ++++++++++++++++++-
 3 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/com/arangodb/NonUniqueResultException.java

diff --git a/src/main/java/com/arangodb/NonUniqueResultException.java b/src/main/java/com/arangodb/NonUniqueResultException.java
new file mode 100644
index 000000000..13109d7bc
--- /dev/null
+++ b/src/main/java/com/arangodb/NonUniqueResultException.java
@@ -0,0 +1,15 @@
+package com.arangodb;
+
+public class NonUniqueResultException extends RuntimeException {
+
+  /**
+   * Constructs a NonUniqueResultException.
+   *
+   * @param resultCount
+   *          The number of actual results.
+   */
+  public NonUniqueResultException(int resultCount) {
+    super("Query did not return a unique result: " + resultCount);
+  }
+
+}
diff --git a/src/main/java/com/arangodb/entity/CursorEntity.java b/src/main/java/com/arangodb/entity/CursorEntity.java
index 29346902c..06f77660a 100644
--- a/src/main/java/com/arangodb/entity/CursorEntity.java
+++ b/src/main/java/com/arangodb/entity/CursorEntity.java
@@ -20,6 +20,7 @@
 import java.util.List;
 import java.util.Map;
 
+import com.arangodb.NonUniqueResultException;
 import com.arangodb.util.CollectionUtils;
 
 /**
@@ -102,6 +103,13 @@ private void rangeCheck(int index) {
   public List<? extends T> getResults() {
     return results;
   }
+  
+  public T getUniqueResult() {
+    int size = size();
+    if (size == 0) return null;
+    if (size > 1) throw new NonUniqueResultException(size);
+    return get(0);
+  }
 
   public boolean isHasMore() {
     return hasMore;
diff --git a/src/test/java/com/arangodb/ArangoDriverCursorTest.java b/src/test/java/com/arangodb/ArangoDriverCursorTest.java
index eee9cae52..ffebf0a45 100644
--- a/src/test/java/com/arangodb/ArangoDriverCursorTest.java
+++ b/src/test/java/com/arangodb/ArangoDriverCursorTest.java
@@ -18,6 +18,7 @@
 
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
+import static org.hamcrest.core.StringStartsWith.startsWith;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThat;
 
@@ -220,5 +221,53 @@ public void test_executeQueryFullCount() throws ArangoException {
     
   }
 
-  
+  @Test
+  public void test_executeQueryUniqueResult() throws ArangoException {
+    
+    // Collectionを作る
+    String collectionName = "unit_test_query_test";
+    try {
+      driver.createCollection(collectionName);
+    } catch (ArangoException e) {}
+    driver.truncateCollection(collectionName);
+    
+    // テストデータを作る
+    for (int i = 0; i < 100; i++) {
+      TestComplexEntity01 value = new TestComplexEntity01(
+          "user_" + (i % 10), 
+          "desc" + (i % 10), 
+          i);
+      driver.createDocument(collectionName, value, null, null);
+    }
+    
+    //String query = "SELECT t FROM unit_test_query_test t WHERE t.age >= @age@";
+    String query = "FOR t IN unit_test_query_test FILTER t.age >= @age LIMIT 2 RETURN t";
+    Map<String, Object> bindVars = new MapBuilder().put("age", 10).get();
+    
+    // 全件とれる範囲
+    {
+      CursorEntity<TestComplexEntity01> result = driver.<TestComplexEntity01>executeQuery(
+          query, bindVars, TestComplexEntity01.class, true, 0);
+      assertThat(result.size(), is(2));
+      assertThat(result.getCount(), is(2));
+      String msg = "";
+      try {
+        result.getUniqueResult();
+      } catch (NonUniqueResultException e) {
+        msg = e.getMessage();     
+      }
+      assertThat(msg, startsWith("Query did not return a unique result:"));
+    }
+    
+    //String query = "SELECT t FROM unit_test_query_test t WHERE t.age >= @age@";
+    query = "FOR t IN unit_test_query_test FILTER t.age == @age LIMIT 2 RETURN t";
+    {
+      CursorEntity<TestComplexEntity01> result = driver.<TestComplexEntity01>executeQuery(
+          query, bindVars, TestComplexEntity01.class, true, 0);
+      assertThat(result.size(), is(1));
+      assertThat(result.getCount(), is(1));
+      TestComplexEntity01 entity = result.getUniqueResult();      
+      assertThat(entity.getAge(), is(10));
+    }
+  }
 }