Ormlite and PostgreSQL - Error inserting text array with custom persister - postgresql

Question

I have been working to setup Ormlite as the primary data access layer between a PostgreSQL database and Java application. Everything has been fairly straightforward, until I started messing with PostgreSQL's array types. In my case, I have two tables that make use of text[] array type. Following the documentation, I created a custom data persister as below:
public class StringArrayPersister extends StringType {
private static final StringArrayPersister singleTon = new StringArrayPersister();
private StringArrayPersister() {
super(SqlType.STRING, new Class<?>[]{String[].class});
}
public static StringArrayPersister getSingleton() {
return singleTon;
}
#Override
public Object javaToSqlArg(FieldType fieldType, Object javaObject) {
String[] array = (String[]) javaObject;
if (array == null) {
return null;
} else {
String join = "";
for (String str : array) {
join += str +",";
}
return "'{" + join.substring(0,join.length() - 1) + "}'";
}
}
#Override
public Object sqlArgToJava(FieldType fieldType, Object sqlArg, int columnPos) {
String string = (String) sqlArg;
if (string == null) {
return null;
} else {
return string.replaceAll("[{}]","").split(",");
}
}
}
And then in my business object implementation, I set up the persister class on the column likeso:
#DatabaseField(columnName = TAGS_FIELD, persisterClass = StringArrayPersister.class)
private String[] tags;
When ever I try inserting a new record with the Dao.create statement, I get an error message saying tags is of type text[], but got character varying... However, when querying existing records from the database, the business object (and text array) load just fine.
Any ideas?
UPDATE:
PostGresSQL 9.2. The exact error message:
Caused by: org.postgresql.util.PSQLException: ERROR: column "tags" is
of type text[] but expression is of type character varying Hint: You
will need to rewrite or cast the expression.

Answer 1

I've not used ormlite before (I generally use MyBatis), however, I believe the proximal issue is this code:
private StringArrayPersister() {
super(SqlType.STRING, new Class<?>[]{String[].class});
}
SqlType.String is mapped to varchar in SQL in the ormlite code, and so therefore I believe is the proximal cause of the error you're getting. See ormlite SQL Data Types info for more detail on that.
Try changing it to this:
private StringArrayPersister() {
super(SqlType.OTHER, new Class<?>[]{String[].class});
}
There may be other tweaks necessary as well to get it fully up and running, but that should get you passed this particular error with the varchar type mismatch.