[LUCENE-2601] Make getAttribute(Class attClass) Generic

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.9.1, 2.9.2, 2.9.3
• Fix Version/s: 3.0
• Component/s: core/other
• Lucene Fields: New
• Assignee: Uwe Schindler
• Reporter: wenbin.zhu
• Created: 14/Aug/10 03:13
• Updated: 28/Aug/22 12:31
• Resolved: 14/Aug/10 06:44

Description

org.apache.lucene.util.AttributeSource

current:
public Attribute getAttribute(Class attClass) {
final Attribute att = (Attribute) this.attributes.get(attClass);
if (att == null)

{ throw new IllegalArgumentException("This AttributeSource does not have the attribute '" + attClass.getName() + "'."); }
return att;
}
sample usage:
TermAttribute termAtt = (TermAttribute)ts.getAttribute(TermAttribute.class)


my improvment:
@SuppressWarnings("unchecked")
public <T> T getAttribute2(Class<? extends Attribute> attClass) {
final T att = (T) this.attributes.get(attClass);
if (att == null) { throw new IllegalArgumentException("This AttributeSource does not have the attribute '" + attClass.getName() + "'."); }

return att;
}
sample usage:
TermAttribute termAtt = ts.getAttribute(TermAttribute.class)