EntryEntity: make content a SyncEntry instead of a string.

It was always of this type, this change just makes it so it's
automatically converted instead of manually.

app/src/main/java/com/etesync/syncadapter/model/JournalModel.java

@@ -88,7 +88,8 @@ public class JournalModel {
         @Column(length = 64, unique = true, nullable = false)
         String uid;
 
-        String content;
+        @Convert(SyncEntryConverter.class)
+        SyncEntry content;
 
         @Index("journal_index")
         @ForeignKey(update = ReferentialAction.CASCADE)
@@ -96,7 +97,7 @@ public class JournalModel {
         Journal journal;
     }
 
-    public static class CollectionInfoConverter implements Converter<CollectionInfo, String> {
+    static class CollectionInfoConverter implements Converter<CollectionInfo, String> {
         @Override
         public Class<CollectionInfo> getMappedType() {
             return CollectionInfo.class;
@@ -122,4 +123,32 @@ public class JournalModel {
             return value == null ? null : CollectionInfo.fromJson(value);
         }
     }
+
+
+    static class SyncEntryConverter implements Converter<SyncEntry, String> {
+        @Override
+        public Class<SyncEntry> getMappedType() {
+            return SyncEntry.class;
+        }
+
+        @Override
+        public Class<String> getPersistedType() {
+            return String.class;
+        }
+
+        @Override
+        public Integer getPersistedSize() {
+            return null;
+        }
+
+        @Override
+        public String convertToPersisted(SyncEntry value) {
+            return value == null ? null : value.toJson();
+        }
+
+        @Override
+        public SyncEntry convertToMapped(Class<? extends SyncEntry> type, String value) {
+            return value == null ? null : SyncEntry.fromJson(value);
+        }
+    }
 }

app/src/main/java/com/etesync/syncadapter/model/SyncEntry.java

@@ -42,7 +42,11 @@ public class SyncEntry {
     }
 
     public static SyncEntry fromJournalEntry(String keyBase64, JournalEntryManager.Entry entry) {
-        return GsonHelper.gson.fromJson(entry.getContent(keyBase64), SyncEntry.class);
+        return fromJson(entry.getContent(keyBase64));
+    }
+
+    static SyncEntry fromJson(String json) {
+        return GsonHelper.gson.fromJson(json, SyncEntry.class);
     }
 
     public String toJson() {

app/src/main/java/com/etesync/syncadapter/syncadapter/SyncManager.java

@@ -231,7 +231,7 @@ abstract public class SyncManager {
     private void persistSyncEntry(String uid, SyncEntry syncEntry) {
         EntryEntity entry = new EntryEntity();
         entry.setUid(uid);
-        entry.setContent(syncEntry.toJson());
+        entry.setContent(syncEntry);
         entry.setJournal(getJournalEntity());
         data.insert(entry);
     }