完整使用JDBC访问数据库

Connection con = null;
PreparedStatement statement = null;
ResultSet res = null;

List<Student> students = new ArrayList<Student>();

List<Student> getAll() {

try {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
            statement = (PreparedStatement) con.createStatement();
            res = statement.executeQuery("SELECT * FROM students");
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            while(res.next()){
                String name = res.getString(1);
                int age = res.getInt(2);
                Student student = new Student(name,age);
                students.add(student);
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        }
        if (res != null) {
            try {
                res.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (statement != null) {
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (con != null) {
            try {
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return students;
    }