add @unique

Author: greenrobot

objectbox-java-api/src/main/java/io/objectbox/annotation/Index.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 ObjectBox Ltd. All rights reserved.
+ * Copyright 2017-2018 ObjectBox Ltd. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,8 @@
 
 /**
  * Specifies that the property should be indexed, which is highly recommended if you do queries using this property.
+ *
+ * To fine tune indexing you can specify {@link IndexType} and/or use {@link #maxValueLength()} if necessary.
  */
 @Retention(RetentionPolicy.CLASS)
 @Target(ElementType.FIELD)
@@ -32,8 +34,4 @@
     /** Only allowed for {@link IndexType#VALUE} and types String and byte[]. */
     int maxValueLength() default 0;
 
-//    /**
-//     * Whether the unique constraint should be created with base on this index
-//     */
-//    boolean unique() default false;
 }

objectbox-java-api/src/main/java/io/objectbox/annotation/Unique.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017 ObjectBox Ltd. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.objectbox.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks values of a property to be unique.
+ * The property will be indexed behind the scenes, just like using @{@link Index}.
+ * Thus you do not need to put an extra @{@link Index} on the property, unless you want to configure the index with
+ * additional parameters.
+ *
+ * Trying to put object with offending values will result in a UniqueViolationException.
+ */
+@Retention(RetentionPolicy.CLASS)
+@Target(ElementType.FIELD)
+public @interface Unique {
+}

objectbox-java/src/main/java/io/objectbox/exception/UniqueViolationException.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2017-2018 ObjectBox Ltd. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.objectbox.exception;
+
+/** Thrown when a @{@link io.objectbox.annotation.Unique} constraint would be violated during a put operation. */
+public class UniqueViolationException extends DbException {
+    public UniqueViolationException(String message) {
+        super(message);
+    }
+}