[empire-db] branch master updated: EMPIREDB-362 DataListHead getDatabase() helper function

[doebele]

This is an automated email from the ASF dual-hosted git repository.

doebele pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/empire-db.git


The following commit(s) were added to refs/heads/master by this push:
     new 1fae785  EMPIREDB-362 DataListHead getDatabase() helper function
1fae785 is described below

commit 1fae785f4d18b18c45e06a25b448f50df0119d8a
Author: Rainer Döbele <doeb...@apache.org>
AuthorDate: Tue Feb 22 09:42:30 2022 +0100

    EMPIREDB-362 DataListHead getDatabase() helper function
---
 .../org/apache/empire/data/list/DataListHead.java  | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git 
a/empire-db/src/main/java/org/apache/empire/data/list/DataListHead.java 
b/empire-db/src/main/java/org/apache/empire/data/list/DataListHead.java
index 6ff041b..40a917f 100644
--- a/empire-db/src/main/java/org/apache/empire/data/list/DataListHead.java
+++ b/empire-db/src/main/java/org/apache/empire/data/list/DataListHead.java
@@ -24,6 +24,8 @@ import org.apache.empire.commons.ObjectUtils;
 import org.apache.empire.commons.Options;
 import org.apache.empire.commons.StringUtils;
 import org.apache.empire.data.ColumnExpr;
+import org.apache.empire.db.DBDatabase;
+import org.apache.empire.db.DBObject;
 
 public class DataListHead implements Serializable
 {
@@ -69,6 +71,27 @@ public class DataListHead implements Serializable
     }
     
     /**
+     * Returns the database instance associated with this DataList (if any)
+     * The database is extracted from the column list 
+     * @param dbClass the desired subclass of DBDatabase
+     * @return the database instance or null if no Database instance of this 
type could be found
+     */
+    @SuppressWarnings("unchecked")
+    public <T extends DBDatabase> T getDatabase(Class<T> dbClass)
+    {
+        for (int i=0; i<columns.length; i++)
+        {
+            if (columns[i] instanceof DBObject)
+            {
+                DBDatabase db = ((DBObject)columns[i]).getDatabase();
+                if (db!=null && dbClass.isAssignableFrom(db.getClass()))
+                    return (T)db;
+            }
+        }
+        return null;
+    }
+    
+    /**
      * Custom value formatting
      * Default is to convert to a String and calls escape() 
      * @param idx the field index