声纳：“关闭此PreparedStatement”

Question

如果我在finally块中将其关闭，为什么Jenkins的SonarQube插件会抱怨open语句？

（我需要在单独的函数中验证数据库连接。）

final String PING = "SELECT 1 from dual";

public boolean validateConnection(Connection conn) {

    PreparedStatement statement = null;
    try{
        if(conn == null){
            LOGGER.log( LogEntries.PingError, "Null connection on PING. Reached max # of connections or network issue. Stats: "+getCacheStatistics() );
            return false;
        }

        if(conn.isClosed()){
            // logger
            return false;   
        }

        statement = conn.prepareStatement( PING ); //%%%%%% SONAR: Close this "PreparedStatement".
        statement.setQueryTimeout(QUERY_TIMEOUT);

        try( ResultSet rs = statement.executeQuery() ){
            if ( rs != null && rs.next() ) {
                return true;
            }
        }catch(Exception exRs){
            // logger
            throw exRs;
        }
    }catch(Exception ex){
        // logger
    }finally{
        try{
            statement.close();
        }catch(Exception excpt){
            // logger
        }
    }
    return false;
}

Answer 1

我已经按照@TT的建议以这种方式重构了代码，而声纳 不再抱怨 。

public boolean validateConnection(Connection conn) {

    LOGGER.log( LogEntries.PingConn );

    try{

        if(conn == null){
            LOGGER.log( LogEntries.PingError, "Null connection on PING. Reached max # of connections or network issue. Stats: "+getCacheStatistics() );
            return false;
        }

        if(conn.isClosed()){
            LOGGER.log( LogEntries.PingError, "Found closed connection during validation PING." );
            return false;   
        }

        try( PreparedStatement statement = conn.prepareStatement( PING ) ){

             statement.setQueryTimeout(QUERY_TIMEOUT);

             try( ResultSet rs = statement.executeQuery() ){

                if ( rs != null && rs.next() ) {
                    return true;
                }
            }
        }

    }catch(Exception ex){
        LOGGER.log( LogEntries.PingError, ex );
    }

    return false;
}

没有“ try-with-resource”，代码可以按以下方式重构，但是在这种情况下，Sonar 仍然抱怨 ：

public boolean validateConnection(Connection conn) {

    LOGGER.log( LogEntries.PingConn );

    PreparedStatement statement = null;
    ResultSet rs = null;
    try{

        if(conn == null){
            LOGGER.log( LogEntries.PingError, "Null connection on PING. Reached max # of connections or network issue. Stats: "+getCacheStatistics() );
            return false;
        }

        if(conn.isClosed()){
            LOGGER.log( LogEntries.PingError, "Found closed connection during validation PING." );
            return false;   
        }

        statement = conn.prepareStatement( PING );
        statement.setQueryTimeout( QUERY_TIMEOUT );
        rs = statement.executeQuery();

        if ( rs != null && rs.next() ) {
            return true;
        }

    }catch(Exception ex){
        LOGGER.log( LogEntries.PingError, ex );
    }finally{
        try {
            if(rs!=null){
                rs.close();
            }
        } catch (SQLException eClosing1) {
            LOGGER.log( LogEntries.PingError, eClosing1 );
        }finally{
            try {
                if(statement!=null){
                    statement.close();
                }
            }catch (SQLException eClosing2) {
                LOGGER.log( LogEntries.PingError, eClosing2 );
            }   
        }
     }

    return false;
}