public void addStudent(List<Student> students) {
        Connection conn = DB.getConnection();
        String sql = "insert into student values(?, ?, ?)";
        PreparedStatement pstmt = null;
        try {
            pstmt = conn.prepareStatement(sql);
            conn.setAutoCommit(false);
            for(int i=0; i<students.size(); i++) {
                Student s = students.get(i);
                pstmt.setInt(1, s.getId());
                pstmt.setString(2, s.getName());
                pstmt.setInt(3, s.getAge());
                pstmt.addBatch();
            }
            pstmt.executeBatch();// 在此卡住,没有出现异常,但就是不动
            conn.commit();
            conn.setAutoCommit(true);
            
        } catch (SQLException e) {
            try {
                conn.rollback();
                conn.setAutoCommit(true);
            } catch (SQLException e1) {
                e1.printStackTrace();
            } 
            e.printStackTrace();
        } finally {
            DB.close(pstmt);
            DB.close(conn);
        }
    }

String sql = "insert into student values(?, ?, ?)";

------解决方案--------------------
怎么写了这么多的conn.setAutoCommit(true);
楼主知道conn.setAutoCommit(true);
是什么意思吗？楼主把conn.setAutoCommit(true);
全部去掉。如果要有程序控制事物，必须是conn.setAutoCommit(false);而且程序必须调用commit或者rollback方法。因此，只需在开始写一次conn.setAutoCommit(false)就可以