Javascript jsp中的窗口取消。如何返回上一页。JS

我的JAVA类控制器：

    public class Controller extends HttpServlet {

    private Chooser chooser = Chooser.INSTANCE;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        processRequest(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        processRequest(req, resp);
    }

    private void processRequest(HttpServletRequest req, HttpServletResponse resp) {
        try {
            String page = chooser.chooseCommand(req.getParameter("command")).execute(req, resp);
            req.getRequestDispatcher(page).forward(req, resp);
        } catch (ServletException | IOException e) {
            e.printStackTrace();
        }
    }
}

接下来，选择页面的类ENUM：

public enum Chooser {

    INSTANCE;

    private Map<String, ICommand> commandMap = new HashMap<>();

    private Chooser() {

        // commands for profession
        commandMap.put("professions", new ProfessionCommand());
        commandMap.put("addProfession", new AddProfessionCommand());
        commandMap.put("saveProfession", new SaveProfessionCommand());
        commandMap.put("deleteProfession", new DeleteProfessionCommand());
        commandMap.put("editProfession", new EditProfessionCommand());

        public ICommand chooseCommand(String command) {
        return commandMap.get(command);
    }

}

我的类DeleteProfessionCommand：

public class DeleteProfessionCommand implements ICommand {

    private ApplicantDBProvider provider = ApplicantDBProvider.INSTANCE;

    @Override
    public String execute(HttpServletRequest request, HttpServletResponse resp) {

        try {
            Long professionId = Long.parseLong(request.getParameter("id"));
            provider.deleteProfession(professionId);
        } catch (Exception e) {
            request.setAttribute("error", e);
            return "pages/error.jsp";
        }

        return "controller?command=professions";
    }
}

在我的jsp中，当我想删除行时，我使用了以下命令：

<a href="controller?command=deleteProfession&id=${profession.getId()}">Delete</a>

我的问题: 当我单击“删除”时，我想获取allert消息，该消息告诉我： “确定要删除”和按钮“是”、“否”。 怎么做，我不知道。因为，我只学java，一个月也学不到。

---

请帮忙。谢谢。

您可以使用javascript实现这一点，在jsp中使用用于删除的锚定标记

<a href="controller?command=deleteProfession&id=${profession.getId()}">Delete</a>

作出这些改变,

<a class="deleteAnchor" data-command="deleteProfession" data-id="${profession.getId()}" href="javascript:void(0);">Delete</a>

然后，在jsp的末尾添加以下内容

<script type="text/javascript" src="//code.jquery.com/jquery-2.1.3.js"></script>
<script type="text/javascript">
$('.deleteAnchor').on('click', function(){
    // confirm will give you a 'ok' and 'cancel' button instead of yes or no
    // you can use one of the other libraries like bootbox to get a nice confirmation dialog box with 'yes' and 'no' buttons
    var result = confirm('Are you sure to delete?');
    if(result) {
        //Delete
        $.ajax({
            url: 'controller',
            data: {'command' : $(this).data('command'), 'id' : $(this).data('id')},
            success: function() {
                //Do something on success
            }
        });
    } else {
        //Dont delete
    }
});
</script>

$（'.deleteAnchor'）。在（'click'，function（）上{
//确认将给您一个“确定”和“取消”按钮，而不是“是”或“否”
//您可以使用其他库（如bootbox）获得一个带有“是”和“否”按钮的确认对话框
var result=confirm（'确定要删除吗？'）；
如果（结果）{
//删除
$.ajax({
url:'控制器'，
数据：{'command'：$（this）.data（'command'），'id'：$（this.data（'id'）}，
成功：函数（）{
//为成功做点什么
}
});
}否则{
//不要删除
}
});

您可以参考更好的确认框

<script type="text/javascript" src="//code.jquery.com/jquery-2.1.3.js"></script>
<script type="text/javascript">
$('.deleteAnchor').on('click', function(){
    // confirm will give you a 'ok' and 'cancel' button instead of yes or no
    // you can use one of the other libraries like bootbox to get a nice confirmation dialog box with 'yes' and 'no' buttons
    var result = confirm('Are you sure to delete?');
    if(result) {
        //Delete
        $.ajax({
            url: 'controller',
            data: {'command' : $(this).data('command'), 'id' : $(this).data('id')},
            success: function() {
                //Do something on success
            }
        });
    } else {
        //Dont delete
    }
});
</script>