我已经创建了一个Java软件，它利用sqlite数据库。整个数据库工作顺利，但经过一段时间的运行应用程序，我收到以下消息（从一个try catch块）：
java.sql.SQLException：[SQLITE_忙碌]数据库文件被锁定（数据库被锁定）
我已经解决了我的问题，每次关闭软件异常上升。但是，有没有办法关闭我的数据库，而不是关闭软件每次？
我有很多疑问，但我的问题总是出现在一个特定的点：

try {
            String query = "select * from StudentsSession where userId=? and course=? and level=?";
            PreparedStatement pst = connectionUsers.prepareStatement(query);
            pst.setString(1, saveUser.getText());
            pst.setString(2, textSubjectQTest);
            st.setString(3, showCurrentLevelLabel.getText());
            ResultSet rs = pst.executeQuery();
            while (rs.next()) {
                count = count + 1;
            }
            pst.close();
            rs.close();
            
        } catch (Exception a) {
            System.out.println(a);
        }
        try {
            String countS, tmpS;
            countS = String.valueOf(count);
            sessionId.setText(countS);
            long unixTime = System.currentTimeMillis() / 1000L;
            tmpS = String.valueOf(unixTime);
            date.setText(tmpS);
            course.setText(textSubjectQTest);

            String query = "insert into StudentsSession (userId,date,course,level,trial,score) values (?,?,?,?,?,-1)";
            PreparedStatement pst = connectionUsers.prepareStatement(query);
            pst.setString(1, saveUser.getText());
            pst.setString(2, tmpS);
            pst.setString(3, textSubjectQTest);
            pst.setString(4, showCurrentLevelLabel.getText());
            pst.setString(5, countS);
            pst.executeUpdate();
            pst.close();
            
        } catch (Exception a) {
            
            System.out.println(a);
            System.exit(0);
        }

        String file1 = "";
        ResultSet ts4;
        try {

            sessionId3 = "";
            String query3 = "select * from studentssession where userid = ?  and course = ? and level = ?";
            PreparedStatement pst__1 = connectionUsers.prepareStatement(query3);
            pst__1.setString(1, saveUser.getText());
            pst__1.setString(2, textSubjectQTest);
            pst__1.setString(3, showCurrentLevelLabel.getText());
            ts4 = pst__1.executeQuery();

            while (ts4.next()) {
                sessionId3 = ts4.getString("sessionId");
            }
            pst__1.close();
            ts4.close();
            obj = new CaptureVideoFromWebCamera();

            file1 = "videos/" + userTextFieldS.getText();

            file1 = file1 + "_" + sessionId3;
            file1 = file1 + ".wmv";
            
            obj.start(file1);

        } catch (Exception e4) {
            e4.getCause();
        }

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有时这段代码会出现异常.