【转】java.lang.StackOverflowError

http://blog.csdn.net/g19920917/article/details/8765638

出现一个java.lang.StackOverflowError异常。弄了半天，又是问高手，又是查资料的。最后发现，解决问题啦！特记录下来！

StackOverflowError是由于当前线程的栈满了  ，也就是函数调用层级过多导致。

比如死递归。

以上是网上查阅的资料。

看懂后，我发现我的项目用的servlet技术，讲doGet()方法添加方法this.doPost()得到解决。

思考：应该是我在实现分页的时候，在点击上一页，下一页时，调用servlet函数后再调回本页面是，出现循环。

result.jsp

<%
    int pageNow = Integer.parseInt((String) request
            .getAttribute("pageNow"));
    if (pageNow != 1) {
        out.println("<a href=Db_sel_Servlet?dbversion=Mysql&pageNow="
                + (pageNow - 1) + ">上一页</a>");
    }
    String s_pageCount = (String) request.getAttribute("pageCount");
    int pageCount = Integer.parseInt(s_pageCount);

    for (int i = 1; i <= pageCount; i++) {
        out.println("<a href=Db_sel_Servlet?dbversion=Mysql&pageNow=" + i
                + ">[" + i + "]</a>");
    }
    if (pageNow != pageCount) {
        out.println("<a href=Db_sel_Servlet?dbversion=Mysql&pageNow="
                + (pageNow + 1) + ">下一页</a>");
    }
%>

Db_sel_Servlet.java

public class Db_sel_Servlet extends HttpServlet {
    public String flag;

    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        this.doPost(req, resp);
    }

    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

        try {
            String s_pageNow=req.getParameter("pageNow");
            int pageNow=Integer.parseInt(s_pageNow);
            System.out.println("DB_sel_Servlet.java---->>>pageNow:"+pageNow);
            flag = req.getParameter("dbversion");
            System.out.println("DB_sel_Servlet---->>" + flag);
            File file = new File("D:\workspace\version");
            FileUtil.WriteFile(file, flag);
            UserDaoImpl userDaoImpl = new UserDaoImpl();
            List<User> user_list = userDaoImpl.getUsersByPage(pageNow);
            int pageCount=userDaoImpl.getPageCount();
            System.out.println("DB_sel_Servlet.java---->>>pageCount:"+pageCount);
            req.setAttribute("result", user_list);
            req.setAttribute("pageCount", pageCount+"");
            req.setAttribute("pageNow",pageNow+"");
            System.out.println(user_list);
            // 清空文件内的内容
            FileUtil.EmptyFile(file);
            // 跳转到用户管理页面
            req.getRequestDispatcher("result.jsp").forward(req, resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }