From 9f70ed17db8f90b639905ef08b92d3bd8c52ee75 Mon Sep 17 00:00:00 2001
From: "Damith C. Rajapakse" <damith@gmail.com>
Date: Wed, 19 Oct 2016 19:20:12 +0800
Subject: [PATCH] [#159] Remove non-static initializers

Remove non-static initializers except one (keep one as an example)
---
 src/main/java/seedu/address/model/AddressBook.java    |  7 +++++++
 .../address/storage/XmlSerializableAddressBook.java   | 11 +++++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/main/java/seedu/address/model/AddressBook.java b/src/main/java/seedu/address/model/AddressBook.java
index 674b07f0ce6f..3332eb6792dc 100644
--- a/src/main/java/seedu/address/model/AddressBook.java
+++ b/src/main/java/seedu/address/model/AddressBook.java
@@ -18,6 +18,13 @@ public class AddressBook implements ReadOnlyAddressBook {
     private final UniquePersonList persons;
     private final UniqueTagList tags;
 
+    /*
+     * The 'unusual' code block below is an non-static initialization block, sometimes used to avoid duplication
+     * between constructors. See https://docs.oracle.com/javase/tutorial/java/javaOO/initial.html
+     *
+     * Note that non-static init blocks are not recommended to use. There are other ways to avoid duplication
+     *   among constructors.
+     */
     {
         persons = new UniquePersonList();
         tags = new UniqueTagList();
diff --git a/src/main/java/seedu/address/storage/XmlSerializableAddressBook.java b/src/main/java/seedu/address/storage/XmlSerializableAddressBook.java
index 2f71f94e66d4..821bc1ce9643 100644
--- a/src/main/java/seedu/address/storage/XmlSerializableAddressBook.java
+++ b/src/main/java/seedu/address/storage/XmlSerializableAddressBook.java
@@ -25,20 +25,19 @@ public class XmlSerializableAddressBook implements ReadOnlyAddressBook {
     @XmlElement
     private List<XmlAdaptedTag> tags;
 
-    {
-        persons = new ArrayList<>();
-        tags = new ArrayList<>();
-    }
-
     /**
      * Empty constructor required for marshalling
      */
-    public XmlSerializableAddressBook() {}
+    public XmlSerializableAddressBook() {
+        persons = new ArrayList<>();
+        tags = new ArrayList<>();
+    }
 
     /**
      * Conversion
      */
     public XmlSerializableAddressBook(ReadOnlyAddressBook src) {
+        this();
         persons.addAll(src.getPersonList().stream().map(XmlAdaptedPerson::new).collect(Collectors.toList()));
         tags.addAll(src.getTagList().stream().map(XmlAdaptedTag::new).collect(Collectors.toList()));
     }