CODEWITHSUNDEEP
javasqlexception
Bobby
Bobby

Reputation: 18305

How can I avoid ResultSet is closed exception in Java?

As soon as my code gets to my while(rs.next()) loop it produces the ResultSet is closed exception. What causes this exception and how can I correct for it?

EDIT: I notice in my code that I am nesting while(rs.next()) loop with another (rs2.next()), both result sets coming from the same DB, is this an issue?

Upvotes: 31

Views: 159933

Answers (14)

Vivekraj Agathariruppu Pugalen
Vivekraj Agathariruppu Pugalen

Reputation: 1

Just create Statement 2 for ResultSet 2

Statement statement2 = connection.createStatement();

ResultSet resultSet2 = statement2.executeQuery("");

If you use Statement 1 for ResultSet 2, Connection is Closed Error comes.

Upvotes: 0

Ilyasse Laaraj
Ilyasse Laaraj

Reputation: 11

I recommend to keep the st2.close(); out of the while, so it doesn't close the connection after the first loop, and then the conncection is closed.

Upvotes: 0

Slartibartfast
Slartibartfast

Reputation: 8805

Proper JDBC call should look something like this is modern Java (Java 7+):

try (
    Connection  conn = DriverManager.getConnection(myUrl,"",""); 
    Statement stmt = conn.createStatement(); 
    ResultSet  rs = stmt.executeQuery(myQuery); 
) {
    while ( rs.next() ) { 
        // process results
    } 
} catch (SqlException e) {
    System.err.println("Got an exception! "); 
    System.err.println(e.getMessage()); 
}

And before the days of try-with-resources syntax, in Java 6 and earlier:

try { 
    Connection conn;
    Statement stmt;
    ResultSet rs; 
    
    try {
        conn = DriverManager.getConnection(myUrl,"",""); 
        stmt = conn.createStatement(); 
        rs = stmt.executeQuery(myQuery); 
        
        while ( rs.next() ) { 
            // process results
        } 
         
    } catch (SqlException e) { 
        System.err.println("Got an exception! "); 
        System.err.println(e.getMessage()); 
    } finally {
        // you should release your resources here
        if (rs != null) { 
            rs.close();
        }

        if (stmt != null) {
            stmt.close();
        }

        if (conn != null) {
            conn.close();
        }
    }
} catch (SqlException e) {
    System.err.println("Got an exception! "); 
    System.err.println(e.getMessage()); 
}

you can close connection (or statement) only after you get result from result set. Safest way is to do it in finally block. However close() could also throe SqlException, hence the other try-catch block.

Upvotes: 5

ciro borrelli
ciro borrelli

Reputation: 1

"result set is closed" happened to me when using tag <collection> in MyBatis nested (one-to-many) xml <select> statement

A Spring solution could be to have a (Java) Spring @Service layer, where class/methods calling MyBatis select-collection statements are annotated with

@Transactional(propagation = Propagation.REQUIRED)

annotations being:

import org.springframework.transaction.annotation.Propagation; 
import org.springframework.transaction.annotation.Transactional;

this solution does not require to set the following datasource properties (i.e., in JBoss EAP standalone*.xml):

<xa-datasource-property name="downgradeHoldCursorsUnderXa">**true**\</xa-datasource-property>
<xa-datasource-property name="resultSetHoldability">**1**</xa-datasource-property>

Upvotes: 0

tremendous7
tremendous7

Reputation: 751

It happens also when using a ResultSet without being in a @Transactional method.

ScrollableResults results = getScrollableResults("select e from MyEntity e");
while (results.next()) {
   ...
}
results.close();

if MyEntity has eager relationships with other entities. the second time results.next() is invoked the ResultSet is closed exception is raised.

so if you use ScrollableResults on entities with eager relationships make sure your method is run transactionally.

Upvotes: 0

Michael Cenzoprano
Michael Cenzoprano

Reputation: 144

A ResultSetClosedException could be thrown for two reasons.

1.) You have opened another connection to the database without closing all other connections.

2.) Your ResultSet may be returning no values. So when you try to access data from the ResultSet java will throw a ResultSetClosedException.

Upvotes: 0

Renato Vasconcellos
Renato Vasconcellos

Reputation: 447

make sure you have closed all your statments and resultsets before running rs.next. Finaly guarantees this

public boolean flowExists( Integer idStatusPrevious, Integer idStatus, Connection connection ) {
    LogUtil.logRequestMethod();

    PreparedStatement ps = null;
    ResultSet rs = null;
    try {
        ps = connection.prepareStatement( Constants.SCRIPT_SELECT_FIND_FLOW_STATUS_BY_STATUS );
        ps.setInt( 1, idStatusPrevious );
        ps.setInt( 2, idStatus );

        rs = ps.executeQuery();

        Long count = 0L;

        if ( rs != null ) {
            while ( rs.next() ) {
                count = rs.getLong( 1 );
                break;
            }
        }

        LogUtil.logSuccessMethod();

        return count > 0L;
    } catch ( Exception e ) {
        String errorMsg = String
            .format( Constants.ERROR_FINALIZED_METHOD, ( e.getMessage() != null ? e.getMessage() : "" ) );
        LogUtil.logError( errorMsg, e );

        throw new FatalException( errorMsg );
    } finally {
        rs.close();
        ps.close();
    }

Upvotes: 1

Praveen
Praveen

Reputation: 21

Check whether you have declared the method where this code is executing as static. If it is static there may be some other thread resetting the ResultSet.

Upvotes: 2

Nathaniel Flath
Nathaniel Flath

Reputation: 16015

You may have closed either the Connection or Statement that made the ResultSet, which would lead to the ResultSet being closed as well.

Upvotes: 6

Itay Maman
Itay Maman

Reputation: 30723

The exception states that your result is closed. You should examine your code and look for all location where you issue a ResultSet.close() call. Also look for Statement.close() and Connection.close(). For sure, one of them gets called before rs.next() is called.

Upvotes: 7

Sugar
Sugar

Reputation: 750

This could be caused by a number of reasons, including the driver you are using.

a) Some drivers do not allow nested statements. Depending if your driver supports JDBC 3.0 you should check the third parameter when creating the Statement object. For instance, I had the same problem with the JayBird driver to Firebird, but the code worked fine with the postgres driver. Then I added the third parameter to the createStatement method call and set it to ResultSet.HOLD_CURSORS_OVER_COMMIT, and the code started working fine for Firebird too. 

static void testNestedRS() throws SQLException {

    Connection con =null;
    try {
        // GET A CONNECTION
        con = ConexionDesdeArchivo.obtenerConexion("examen-dest");
        String sql1 = "select * from reportes_clasificacion";

        Statement st1 = con.createStatement(
                ResultSet.TYPE_SCROLL_INSENSITIVE,
                ResultSet.CONCUR_READ_ONLY, 
                ResultSet.HOLD_CURSORS_OVER_COMMIT);
        ResultSet rs1 = null;

        try {
            // EXECUTE THE FIRST QRY
            rs1 = st1.executeQuery(sql1);

            while (rs1.next()) {
                // THIS LINE WILL BE PRINTED JUST ONCE ON
                                    // SOME DRIVERS UNLESS YOU CREATE THE STATEMENT 
                // WITH 3 PARAMETERS USING 
                                    // ResultSet.HOLD_CURSORS_OVER_COMMIT
                System.out.println("ST1 Row #: " + rs1.getRow());

                String sql2 = "select * from reportes";
                Statement st2 = con.createStatement(
                        ResultSet.TYPE_SCROLL_INSENSITIVE,
                        ResultSet.CONCUR_READ_ONLY);

                // EXECUTE THE SECOND QRY.  THIS CLOSES THE FIRST 
                // ResultSet ON SOME DRIVERS WITHOUT USING 
                                    // ResultSet.HOLD_CURSORS_OVER_COMMIT

                st2.executeQuery(sql2);

                st2.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            rs1.close();
            st1.close();
        }

    } catch (SQLException e) {

    } finally {
        con.close();

    }

}

b) There could be a bug in your code. Remember that you cannot reuse the Statement object, once you re-execute a query on the same statement object, all the opened resultsets associated with the statement are closed. Make sure you are not closing the statement.

Upvotes: 25

Kulbhushan Chaskar
Kulbhushan Chaskar

Reputation: 353

I got same error everything was correct only i was using same statement interface object to execute and update the database. After separating i.e. using different objects of statement interface for updating and executing query i resolved this error. i.e. do get rid from this do not use same statement object for both updating and executing the query.

Upvotes: 3

Apocalisp
Apocalisp

Reputation: 35054

Sounds like you executed another statement in the same connection before traversing the result set from the first statement. If you're nesting the processing of two result sets from the same database, you're doing something wrong. The combination of those sets should be done on the database side.

Upvotes: 53

job
job

Reputation: 9263

Also, you can only have one result set open from each statement. So if you are iterating through two result sets at the same time, make sure they are executed on different statements. Opening a second result set on one statement will implicitly close the first. http://java.sun.com/javase/6/docs/api/java/sql/Statement.html

Upvotes: 10

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