Getting column length from Hibernate mappings?

You can get to it but it's not easy. You might want to do something like below at startup and store a static cache of the values. There are a lot of special cases to deal with (inheritance, etc), but it should work for simple single-column mappings. I might have left out some instanceof and null checks.

for (Iterator iter=configuration.getClassMappings(); iter.hasNext();) {    PersistentClass persistentClass = (PersistentClass)iter.next();    for (Iterator iter2=persistentClass.getPropertyIterator(); iter2.hasNext();) {       Property property = (Property)iter2.next();       String class = persistentClass.getClassName();       String attribute = property.getName();       int length = ((Column)property.getColumnIterator().next()).getLength();    }  }

Based on Brian's answer, this is what I ended up doing.

private static final Configuration configuration = new Configuration().configure();public static int getColumnLength(String className, String propertyName) {    PersistentClass persistentClass = configuration.getClassMapping(className);    Property property = persistentClass.getProperty(propertyName);    int length = ((Column) property.getColumnIterator().next()).getLength();    return length;}

This appears to be working well. Hope this is helpful to anyone who stumbles upon this question.

My preferred development pattern is to base the column length on a constant, which can be easily referenced:

class MyEntity {   public static final int FIELD_LENGTH = 500;   @Column(length = FIELD_LENGTH)   String myField;   ...}