How can I get the value of HashTable inside the arrayList?
I have the following code:
public ArrayList resultSetToArrayList(ResultSet rs) {
ArrayList list = new ArrayList();
try {
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
int rowcount = 0;
while (rs.next()) {
Hashtable row = new Hashtable();
for (int i = 1; i <= columns; ++i) {
row.put(md.getColumnName(i), rs.getString(i));
}
list.add(rowcount, row);
rowcount++;
}
} catch (Exception e) {
e.printStackTrace();
}
return list;
}
You appear to be using raw types
and Hashtable
instead of a HashMap
. I think you're asking for something like
public List<Map<String, String>> resultSetToArrayList(ResultSet rs) {
List<Map<String, String>> list = new ArrayList<>();
try {
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
while (rs.next()) {
Map<String, String> row = new HashMap<>();
for (int i = 1; i <= columns; ++i) {
row.put(md.getColumnName(i), rs.getString(i));
}
list.add(row);
}
} catch (Exception e) {
e.printStackTrace();
}
return list;
}
As for getting the values back out of a Map
, you might iterate the Map.keySet()
like
for (String key : map.keySet()) {
System.out.printf("%s = %s%n", key, map.get(key));
}
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