API docs: fix various warnings #259

- empty <p> tag
- unescaped HTML characters
- not a warning, but add a missing space

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/relation/ToMany.java

@@ -58,7 +58,7 @@
  * <pre>{@code
  * // Java
  * @Entity
- * public class Student{
+ * public class Student {
  *     private ToMany<Teacher> teachers;
  * }
  *
@@ -85,7 +85,6 @@
  * <p>
  * To apply (persist) the changes to the database, call {@link #applyChangesToDb()} or put the object with the ToMany.
  * For important details, see the notes about relations of {@link Box#put(Object)}.
- * <p>
  * <pre>{@code
  * // Example 1: add target objects to a relation
  * student.getTeachers().add(teacher1);

objectbox-java/src/main/java/io/objectbox/relation/ToOne.java

@@ -61,7 +61,6 @@
  * </ul>
  * <p>
  * Then, to persist the changes {@link Box#put} the object with the ToOne.
- * <p>
  * <pre>{@code
  * // Example 1: create a relation
  * order.getCustomer().setTarget(customer);

objectbox-java/src/main/java/io/objectbox/sync/Sync.java

@@ -44,7 +44,7 @@ public static boolean isServerAvailable() {
     }
 
     /**
-     * Returns true if the included native (JNI) ObjectBox library supports Sync hybrids (server & client).
+     * Returns true if the included native (JNI) ObjectBox library supports Sync hybrids (server and client).
      */
     public static boolean isHybridAvailable() {
         return isAvailable() && isServerAvailable();

objectbox-java/src/main/java/io/objectbox/sync/SyncFlags.java

@@ -25,7 +25,7 @@
 public final class SyncFlags {
   private SyncFlags() { }
   /**
-   * Enable (rather extensive) logging on how IDs are mapped (local <-> global)
+   * Enable (rather extensive) logging on how IDs are mapped (local &lt;-&gt; global)
    */
   public static final int DebugLogIdMapping = 1;
   /**

objectbox-java/src/main/java/io/objectbox/sync/SyncHybrid.java

@@ -24,7 +24,7 @@
 /**
  * Combines the functionality of a Sync client and a Sync server.
  * <p>
- * It is typically used in local cluster setups, in which a "hybrid" functions as a client & cluster peer (server).
+ * It is typically used in local cluster setups, in which a "hybrid" functions as a client and cluster peer (server).
  * <p>
  * Call {@link #getStore()} to retrieve the store. To set sync listeners use the {@link SyncClient} that is available
  * from {@link #getClient()}.