时间戳

首页 > 解决方案 > 项目FreeMarker模板添加分页后不显示消息

java - 项目FreeMarker模板添加分页后不显示消息

问题描述

在应用程序中，有一个带有消息的公共页面，其中显示所有用户的所有消息，并且有一个单独的页面（用户配置文件），其中只有登录用户的消息可见。在我在页面上添加分页之前，一切正常，但现在一切都很好，只有在主页上，消息和页码是可见的，但是如果你用登录的用户打开页面（用户配置文件），页码和消息是不显示，而是 pages 给出错误 FreeMarker 模板错误。

main.ftl 是包含所有消息的主页，所有消息都在其中运行，显示 messageList.ftl 中描述的所有消息。

错误

ERROR 6588 --- [nio-8080-exec-5] freemarker.runtime                       : Error executing FreeMarker template

freemarker.core._MiscTemplateException: When calling macro "pager", required parameter "url" (parameter #1) was specified, but had null/missing value.

----
Tip: If the parameter value expression on the caller side is known to be legally null/missing, you may want to specify a default value for it with the "!" operator, like paramValue!defaultValue.
----

----
FTL stack trace ("~" means nesting-related):
    - Failed at: #macro pager url page  [in template "parts/pager.ftl" in macro "pager" at line 1, column 1]
    - Reached through: @p.pager url, page  [in template "parts/messageList.ftl" at line 4, column 1]
    - Reached through: #include "parts/messageList.ftl"  [in template "userMessages.ftl" at line 40, column 5]
    ~ Reached through: #nested  [in template "parts/common.ftl" in macro "page" at line 18, column 1]
    ~ Reached through: @c.page  [in template "userMessages.ftl" at line 3, column 1]

userMessages.ftl

    <#import "parts/common.ftl" as c>

<@c.page>
<h3>${userChannel.username}</h3>
    <#if !isCurrentUser>
        <#if isSubscriber>
        <a class="btn btn-info" href="/user/unsubscribe/${userChannel.id}">Unsubscribe</a>
        <#else>
        <a class="btn btn-info" href="/user/subscribe/${userChannel.id}">Subscribe</a>
        </#if>
    </#if>
<div class="container my-3">
    <div class="row">
        <div class="col">
            <div class="card">
                <div class="card-body">
                    <div class="card-title">Subscriptions</div>
                    <h3 class="card-text">
                        <a href="/user/subscriptions/${userChannel.id}/list">${subscriptionsCount}</a>
                    </h3>
                </div>
            </div>
        </div>
        <div class="col">
            <div class="card">
                <div class="card-body">
                    <div class="card-title">Subscribers</div>
                    <h3 class="card-text">
                        <a href="/user/subscribers/${userChannel.id}/list">${subscribersCount}</a>
                    </h3>
                </div>
            </div>
        </div>
    </div>
</div>
    <#if isCurrentUser>
        <#include "parts/messageEdit.ftl" />
    </#if>

    <#include "parts/messageList.ftl" />
</@c.page>

寻呼机.ftl

<#macro pager url page >
<#if page.getTotalPages() gt 7>
    <#assign
    totalPages = page.getTotalPages()
    pageNumber = page.getNumber() + 1
    head = (pageNumber > 4)?then([1, -1], [1, 2, 3])
    tail = (pageNumber < totalPages - 3)?then([-1, totalPages], [totalPages - 2, totalPages - 1, totalPages])
    bodyBefore = (pageNumber > 4 && pageNumber < totalPages - 1)?then([pageNumber - 2, pageNumber - 1], [])
    bodyAfter = (pageNumber > 2 && pageNumber < totalPages - 3)?then([pageNumber + 1, pageNumber + 2], [])
    body = head + bodyBefore + (pageNumber > 3 && pageNumber < totalPages - 2)?then([pageNumber], []) + bodyAfter + tail
    >
<#else>
    <#assign body = 1..page.getTotalPages()>
</#if>
<div class="mt-3">
    <ul class="pagination">
        <li class="page-item disabled">
            <a class="page-link" href="#" tabindex="-1">Pages</a>
        </li>
        <#list body as p>
            <#if (p - 1) == page.getNumber()>
                <li class="page-item active">
                    <a class="page-link" href="#" tabindex="-1">${p}</a>
                </li>
            <#elseif p == -1>
                <li class="page-item disabled">
                    <a class="page-link" href="#" tabindex="-1">...</a>
                </li>
            <#else>
                <li class="page-item">
                    <a class="page-link" href="${url}?page=${p - 1}&size=${page.getSize()}" tabindex="-1">${p}</a>
                </li>
            </#if>
        </#list>
    </ul>

    <ul class="pagination">
        <li class="page-item disabled">
            <a class="page-link" href="#" tabindex="-1">Quantity</a>
        </li>
        <#list [5, 10, 25, 50] as c>
            <#if c == page.getSize()>
                <li class="page-item active">
                    <a class="page-link" href="#" tabindex="-1">${c}</a>
                </li>
            <#else>
                <li class="page-item">
                    <a class="page-link" href="${url}?page=${page.getNumber()}&size=${c}" tabindex="-1">${c}</a>
                </li>
            </#if>
        </#list>
    </ul>
</div>

消息列表.ftl

<#include "security.ftl">
<#import "pager.ftl" as p>

<@p.pager url page />

<div class="card-columns" id="message-list">
    <#list page.content as message>
        <div class="card my-3" data-id="${message.id}"/>
            <#if message.filename??>
                <img src="/img/${message.filename}" class="card-img-top" />
            </#if>
            <div class="m-2">
                <span>${message.text}</span><br/>
                <i>#${message.tag}</i>
            </div>
            <div class="card-footer text-muted">
                <a href="/user-messages/${message.author.id}">${message.authorName}</a>
                <#if message.author.id == currentUserId>
                    <a class="btn btn-primary" href="/user-messages/${message.author.id}?message=${message.id}">
                        Edit
                    </a>
                </#if>
            </div>
        </div>
    <#else>
        No message
    </#list>
</div>

<@p.pager url page />

常见的.ftl

<#macro page>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="/static/style.css" />

    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />

    <!-- Bootstrap CSS -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous" />
    <script src='https://www.google.com/recaptcha/api.js'></script>
</head>
<body>
    <#include "navbar.ftl">
<div class="container mt-5">
<#nested>
</div>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js" integrity="sha384-smHYKdLADwkXOn1EmN1qk/HfnUcbVRZyYmZ4qpPea6sjB/pTJ0euyQp0Mk8ck+5T" crossorigin="anonymous"></script>
</body>
</html>
</#macro>

主文件

<#import "parts/common.ftl" as c>

<@c.page>
<div class="form-row">
    <div class="form-group col-md-6">
        <form method="get" action="/main" class="form-inline">
            <input type="text" name="filter" class="form-control" value="${filter?ifExists}" placeholder="Search by tag" />
            <button type="submit" class="btn btn-primary ml-2">Search</button>
        </form>
    </div>
</div>

<#include "parts/messageEdit.ftl" />

<#include "parts/messageList.ftl" />

</@c.page>

主控制器.java

package coding.domain.controller;

import coding.domain.domain.Message;
import coding.domain.domain.User;
import coding.domain.repos.MessageRepo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.web.PageableDefault;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.util.StringUtils;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import javax.validation.Valid;
import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import java.util.UUID;

@Controller
public class MainController {
    @Autowired
    private MessageRepo messageRepo;

    @Value("${upload.path}")
    private String uploadPath;

    @GetMapping("/")
    public String greeting(Map<String, Object> model) {
        return "greeting";
    }

    @GetMapping("/main")
    public String main(
            @RequestParam(required = false, defaultValue = "") String filter,
            Model model,
            @PageableDefault(sort = { "id" }, direction = Sort.Direction.DESC) Pageable pageable
    ) {
        Page<Message> page;

        if (filter != null && !filter.isEmpty()) {
            page = messageRepo.findByTag(filter, pageable);
        } else {
            page = messageRepo.findAll(pageable);
        }

        model.addAttribute("page", page);
        model.addAttribute("url", "/main");
        model.addAttribute("filter", filter);
        return "main";
    }

    @PostMapping("/main")
    public String add(
            @AuthenticationPrincipal User user,
            @Valid Message message,
            BindingResult bindingResult,
            Model model,
            @RequestParam("file") MultipartFile file
    ) throws IOException {
        message.setAuthor(user);

        if (bindingResult.hasErrors()) {
            Map<String, String> errorsMap = ControllerUtils.getErrors(bindingResult);

            model.mergeAttributes(errorsMap);
            model.addAttribute("message", message);
        } else {
            saveFile(message, file);

            model.addAttribute("message", null);

            messageRepo.save(message);
        }

        Iterable<Message> messages = messageRepo.findAll();

        model.addAttribute("messages", messages);

        return "main";
    }

    private void saveFile(@Valid Message message, @RequestParam("file") MultipartFile file) throws IOException {
        if (file != null && !file.getOriginalFilename().isEmpty()) {
            File uploadDir = new File(uploadPath);

            if (!uploadDir.exists()) {
                uploadDir.mkdir();
            }

            String uuidFile = UUID.randomUUID().toString();
            String resultFilename = uuidFile + "." + file.getOriginalFilename();

            file.transferTo(new File(uploadPath + "/" + resultFilename));

            message.setFilename(resultFilename);
        }
    }

    @GetMapping("/user-messages/{user}")
    public String userMessges(
            @AuthenticationPrincipal User currentUser,
            @PathVariable User user,
            Model model,
            @RequestParam(required = false) Message message
    ) {
        Set<Message> messages = user.getMessages();

        model.addAttribute("userChannel", user);
        model.addAttribute("subscriptionsCount", user.getSubscriptions().size());
        model.addAttribute("subscribersCount", user.getSubscribers().size());
        model.addAttribute("isSubscriber", user.getSubscribers().contains(currentUser));
        model.addAttribute("messages", messages);
        model.addAttribute("message", message);
        model.addAttribute("isCurrentUser", currentUser.equals(user));

        return "userMessages";
    }

    @PostMapping("/user-messages/{user}")
    public String updateMessage(
            @AuthenticationPrincipal User currentUser,
            @PathVariable Long user,
            @RequestParam("id") Message message,
            @RequestParam("text") String text,
            @RequestParam("tag") String tag,
            @RequestParam("file") MultipartFile file
    ) throws IOException {
        if (message.getAuthor().equals(currentUser)) {
            if (!StringUtils.isEmpty(text)) {
                message.setText(text);
            }

            if (!StringUtils.isEmpty(tag)) {
                message.setTag(tag);
            }

            saveFile(message, file);

            messageRepo.save(message);
        }

        return "redirect:/user-messages/" + user;
    }
}

标签： javaspringwebweb-applicationsfreemarker

解决方案

如异常描述，您可以使用默认运算符

概要： unsafe_expr!default_expr

在你的情况下：

 ${url|"/main")

您也可以在宏的参数中设置默认值：

param1、param2、...等：局部变量的名称存储参数值（不是表达式），可选地后跟 = 和默认值（即表达式）。默认值甚至可以是另一个参数，例如 <#macro section title label=title

在你的情况下：

 <#macro pager url="/main" page >

推荐阅读