求高手解决！不知道是出了什么原因？

Question

服务器报错 而且一直重复报 页面插入一次数据 数据库插入了多条一样 的数据啊
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:216)
at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:545)
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:216)
at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:545)
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:216)
at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:545)
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:216)
at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:494)
at org.apache.struts.action.RequestProcessor.processLocale(RequestProcessor.java:621)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:177)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:630)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1085)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:398)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:241)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)

Answer 1

at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:216)
at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:545)楼主看一下 这一段异常时不时出现了多次，
我想估计应该是你有某个地方写错了。
既然插入数据库的数据存在就说明dao  应该没有错。。
我想应该是你提交了多次，
最好楼主可以吧 代码贴出来

Answer 2

public interface CategoryDao {
public void save(Category category);

public void delete(int id);

public void update(Category category);

public Category get(int id);

public List<Category> find();

public List<Category> find(int offset,int pageSize);
}
public class CategoryDaoImpl extends HibernateDaoSupport implements
CategoryDao{
public void delete(int id) {
getHibernateTemplate().delete(get(id));
}
public List<Category> find() {
List<Category> categories = (List<Category>) getHibernateTemplate().execute(new HibernateCallback(){
@Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List<Category> category = session.createCriteria(Category.class).list();
return category;
}

}); return categories;
}
public List<Category> find(final int offset, final int pageSize) {
List<Category> categories = (List<Category>) getHibernateTemplate().execute(new HibernateCallback(){ @Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List<Category> category = session.createCriteria(Category.class).setFirstResult((offset-1)*pageSize).setMaxResults(pageSize).list();
return category;
}

});
return categories;
}
public Category get(final int id) {
Category category = (Category)getHibernateTemplate().execute(new HibernateCallback(){ @Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Category category =  (Category)session.createCriteria(Category.class).add(Restrictions.eq("id", id)).list().get(0);
return category;
}

});
return category;
}
public void save(Category category) {
getHibernateTemplate().save(category);
}
public void update(Category category) {
getHibernateTemplate().saveOrUpdate(category);
}
}
public interface CategoryService {

public void addCategory(Category category);

public void deleteCategory(int id);

public void updateCategory(Category category);

public Category getCategory(int id);

public List<Category> findCategories();

public List<Category> findCategories(int offset,int pageSize);


}
public class CategoryServiceImpl implements CategoryService {

private CategoryDao categoryDao;

public CategoryDao getCategoryDao() {
return categoryDao;
} public void setCategoryDao(CategoryDao categoryDao) {
this.categoryDao = categoryDao;
} @Override
public void addCategory(Category category) {
categoryDao.save(category);
} @Override
public void deleteCategory(int id) {
categoryDao.delete(id);
} @Override
public List<Category> findCategories() {
List<Category> categories = categoryDao.find();
return categories;
} @Override
public List<Category> findCategories(int offset, int pageSize) {
return categoryDao.find(offset, pageSize);
} @Override
public Category getCategory(int id) {
return categoryDao.get(id);
} @Override
public void updateCategory(Category category) {
categoryDao.update(category);
}}
public class CategoryAction extends DispatchAction { private CategoryService categoryService;


public CategoryService getCategoryService() {
return categoryService;
} public void setCategoryService(CategoryService categoryService) {
this.categoryService = categoryService;
} public ActionForward unspecified(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
List<Category> categories = categoryService.findCategories();
request.setAttribute("categories", categories);
return mapping.findForward("listCategories");
}

public ActionForward addUI(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {

return mapping.findForward("addUI");
}

public ActionForward add(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
CategoryForm categoryForm = (CategoryForm) form;
Category category = new Category();
category.setName(categoryForm.getName());
categoryService.addCategory(category);

return mapping.findForward("showCategory");
}

public ActionForward editUI(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
CategoryForm categoryForm = (CategoryForm)form;
Category category = categoryService.getCategory(categoryForm.getId());

categoryForm.setName(category.getName());
return mapping.findForward("editUI");
}

public ActionForward edit(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
CategoryForm categoryForm = (CategoryForm) form;
Category category = new Category();
category.setName(categoryForm.getName());
categoryService.updateCategory(category);
return mapping.findForward("showCategory");
}

public ActionForward delete(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
CategoryForm categoryForm = (CategoryForm) form;
categoryService.deleteCategory(Integer.parseInt(request.getParameter("id")));
return mapping.findForward("showCategory");
}

public ActionForward changeOrder(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
return super.execute(mapping, form, request, response);
}


}

Answer 3

估计是“提交数据的Action类的方法”写的有问题。

Answer 4

public interface CategoryDao {
public void save(Category category);public void delete(int id);public void update(Category category);public Category get(int id);public List<Category> find();public List<Category> find(int offset,int pageSize);
}

Answer 5

public class CategoryDaoImpl extends HibernateDaoSupport implements
CategoryDao{
public void delete(int id) {
getHibernateTemplate().delete(get(id));
}
public List<Category> find() {
List<Category> categories = (List<Category>) getHibernateTemplate().execute(new HibernateCallback(){
@Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List<Category> category = session.createCriteria(Category.class).list();
return category;
}});return categories;
}
public List<Category> find(final int offset, final int pageSize) {
List<Category> categories = (List<Category>) getHibernateTemplate().execute(new HibernateCallback(){@Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List<Category> category = session.createCriteria(Category.class).setFirstResult((offset-1)*pageSize).setMaxResults(pageSize).list();
return category;
}});
return categories;
}
public Category get(final int id) {
Category category = (Category)getHibernateTemplate().execute(new HibernateCallback(){@Override
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Category category = (Category)session.createCriteria(Category.class).add(Restrictions.eq("id", id)).list().get(0);
return category;
}});
return category;
}
public void save(Category category) {
getHibernateTemplate().save(category);
}
public void update(Category category) {
getHibernateTemplate().saveOrUpdate(category);
}
}

Answer 6

public interface CategoryService {public void addCategory(Category category);public void deleteCategory(int id);public void updateCategory(Category category);public Category getCategory(int id);public List<Category> findCategories();public List<Category> findCategories(int offset,int pageSize);
}
public class CategoryServiceImpl implements CategoryService {private CategoryDao categoryDao;public CategoryDao getCategoryDao() {
return categoryDao;
}public void setCategoryDao(CategoryDao categoryDao) {
this.categoryDao = categoryDao;
}@Override
public void addCategory(Category category) {
categoryDao.save(category);
}@Override
public void deleteCategory(int id) {
categoryDao.delete(id);
}@Override
public List<Category> findCategories() {
List<Category> categories = categoryDao.find();
return categories;
}@Override
public List<Category> findCategories(int offset, int pageSize) {
return categoryDao.find(offset, pageSize);
}@Override
public Category getCategory(int id) {
return categoryDao.get(id);
}@Override
public void updateCategory(Category category) {
categoryDao.update(category);
}}

Answer 7

通过dug模式，从action-service-dao一部一部调式，可以解决问题。