Why do I get a "Null value was assigned to a property of primitive type setter of" error message when using HibernateCriteriaBuilder in Grails

According to this SO thread, the solution is to use the non-primitive wrapper types; e.g., Integer instead of int.

A null value cannot be assigned to a primitive type, like int, long, boolean, etc. If the database column that corresponds to the field in your object can be null, then your field should be a wrapper class, like Integer, Long, Boolean, etc.

The danger is that your code will run fine if there are no nulls in the DB, but will fail once nulls are inserted.

And you can always return the primitive type from the getter. Ex:

  private Integer num;

  public void setNum(Integer i) {
    this.num = i;
  }

  public int getNum() {
    return this.num;
  }

But in most cases you will want to return the wrapper class.

So either set your DB column to not allow nulls, or use a wrapper class.

A primitive type cannot be null. So the solution is replace primitive type with primitive wrapper class in your tableName.java file. Such as:

@Column(nullable=true, name="client_os_id")
private Integer client_os_id;

public int getClient_os_id() {
    return client_os_id;
}

public void setClient_os_id(int clientOsId) {
    client_os_id = clientOsId;
}

reference http://en.wikipedia.org/wiki/Primitive_wrapper_class to find wrapper class of a primivite type.