Does try-with-resources on a statement close the connection?
In this code, would the connection be closed?
Connection con = DriverManager.getConnection(dbUrl, user, pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(query);
}
Something in my code is unexpectedly closing the connection, I'd like to make sure it isn't this.
java try-with-resources
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
add a comment |
In this code, would the connection be closed?
Connection con = DriverManager.getConnection(dbUrl, user, pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(query);
}
Something in my code is unexpectedly closing the connection, I'd like to make sure it isn't this.
java try-with-resources
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
add a comment |
In this code, would the connection be closed?
Connection con = DriverManager.getConnection(dbUrl, user, pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(query);
}
Something in my code is unexpectedly closing the connection, I'd like to make sure it isn't this.
java try-with-resources
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
In this code, would the connection be closed?
Connection con = DriverManager.getConnection(dbUrl, user, pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(query);
}
Something in my code is unexpectedly closing the connection, I'd like to make sure it isn't this.
java try-with-resources
java try-with-resources
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
edited Nov 23 '18 at 1:22
gigosaurus
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
asked Jan 9 '15 at 23:29
gigosaurusgigosaurus
1315
1315
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
No, invoking close on Statement will not close Connection. This would prevent us from creating next statement on already opened connection which means we would have to create new Connection (which can be expensive operation) for each Statement.
You can test it very easily. Just try to create another statement after previous one was closed.
Connection con = DriverManager.getConnection(dbUrl,user,pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sqlQuery1);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}//here `st` will be closed automatically by try-with-resources
try (Statement st = con.createStatement()) {//lets try to create next statement
ResultSet rs = st.executeQuery(sqlQuery2);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}
simplePrint method may look like this:
public static void simplePrint(ResultSet rs) throws SQLException {
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
for (int i = 1; i <= meta.getColumnCount(); i++) {
System.out.print(rs.getObject(i)+"t");
}
System.out.println();
}
}
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
No, invoking close on Statement will not close Connection. This would prevent us from creating next statement on already opened connection which means we would have to create new Connection (which can be expensive operation) for each Statement.
You can test it very easily. Just try to create another statement after previous one was closed.
Connection con = DriverManager.getConnection(dbUrl,user,pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sqlQuery1);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}//here `st` will be closed automatically by try-with-resources
try (Statement st = con.createStatement()) {//lets try to create next statement
ResultSet rs = st.executeQuery(sqlQuery2);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}
simplePrint method may look like this:
public static void simplePrint(ResultSet rs) throws SQLException {
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
for (int i = 1; i <= meta.getColumnCount(); i++) {
System.out.print(rs.getObject(i)+"t");
}
System.out.println();
}
}
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
add a comment |
No, invoking close on Statement will not close Connection. This would prevent us from creating next statement on already opened connection which means we would have to create new Connection (which can be expensive operation) for each Statement.
You can test it very easily. Just try to create another statement after previous one was closed.
Connection con = DriverManager.getConnection(dbUrl,user,pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sqlQuery1);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}//here `st` will be closed automatically by try-with-resources
try (Statement st = con.createStatement()) {//lets try to create next statement
ResultSet rs = st.executeQuery(sqlQuery2);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}
simplePrint method may look like this:
public static void simplePrint(ResultSet rs) throws SQLException {
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
for (int i = 1; i <= meta.getColumnCount(); i++) {
System.out.print(rs.getObject(i)+"t");
}
System.out.println();
}
}
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
add a comment |
No, invoking close on Statement will not close Connection. This would prevent us from creating next statement on already opened connection which means we would have to create new Connection (which can be expensive operation) for each Statement.
You can test it very easily. Just try to create another statement after previous one was closed.
Connection con = DriverManager.getConnection(dbUrl,user,pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sqlQuery1);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}//here `st` will be closed automatically by try-with-resources
try (Statement st = con.createStatement()) {//lets try to create next statement
ResultSet rs = st.executeQuery(sqlQuery2);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}
simplePrint method may look like this:
public static void simplePrint(ResultSet rs) throws SQLException {
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
for (int i = 1; i <= meta.getColumnCount(); i++) {
System.out.print(rs.getObject(i)+"t");
}
System.out.println();
}
}
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
No, invoking close on Statement will not close Connection. This would prevent us from creating next statement on already opened connection which means we would have to create new Connection (which can be expensive operation) for each Statement.
You can test it very easily. Just try to create another statement after previous one was closed.
Connection con = DriverManager.getConnection(dbUrl,user,pass);
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sqlQuery1);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}//here `st` will be closed automatically by try-with-resources
try (Statement st = con.createStatement()) {//lets try to create next statement
ResultSet rs = st.executeQuery(sqlQuery2);
simplePrint(rs);
} catch (SQLException e) {
e.printStackTrace();
}
simplePrint method may look like this:
public static void simplePrint(ResultSet rs) throws SQLException {
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
for (int i = 1; i <= meta.getColumnCount(); i++) {
System.out.print(rs.getObject(i)+"t");
}
System.out.println();
}
}
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
edited Jan 9 '15 at 23:47
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
answered Jan 9 '15 at 23:39
PshemoPshemo
94.6k15131191
94.6k15131191
add a comment |
add a comment |
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