java使用Thymeleaf和Spring动态链接到图像
我正在做一项作业,正在使用thymeleaf和spring创建网页。我有它的大部分工作,但我似乎无法得到一个图像加载
我的html:
<!DOCTYPE html>
<html xmlns:th="https//www.thymeleaf.org">
<head>
<title>A Course</title>
<link rel="stylesheet" type="text/css"
href="/css/ReviewPageStyleSheet.css" />
</head>
<body>
<h1 id="heading">A Single Course</h1>
<img th:src="@{${'/images/' + review.image}}">
<div id="list" th:each="review: ${reviews}">
<p th:text="${review.title}"></p>
<p th:text="${review.category}"></p>
<a href="http://localhost:8080/show-all-reviews">Back to home</a>
</div>
</body>
</html>
我的控制器:
package org.wecancodeit.reviewsite;
import javax.annotation.Resource;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class ReviewSiteController {
@Resource
ReviewSiteRepository reviewsRepo;
@RequestMapping("/show-all-reviews")
public String findAllReviews(Model model) {
model.addAttribute("reviews", reviewsRepo.findAll());
return "reviews";
}
@RequestMapping("review")
public String findOneReview(@RequestParam(value = "id") Long id, Model model) {
model.addAttribute("reviews", reviewsRepo.getOneCourse(id));
return "review";
}
}
我的存储库:
package org.wecancodeit.reviewsite;
import java.util.Collection;
import java.util.HashMap;
import org.springframework.stereotype.Repository;
@Repository
public class ReviewSiteRepository {
private HashMap<Long, Review> reviewList = new HashMap<Long, Review>();
public ReviewSiteRepository() {
Review springMVC = new Review(1L, "Spring Boot & MVC",
"This page reviews information on how to use Spring Boot & MVC and its functionality. ", "java.png");
Review thymeleaf = new Review(2L, "Thymeleaf",
"This page reviews information on what Thymeleaf is, and how to use it.", "thyme.jpg");
Review htmlcss = new Review(3L, "HTML & CSS", "This page reviews what HTML and CSS are, and how to use them. ",
"html.png");
reviewList.put(springMVC.getId(), springMVC);
reviewList.put(thymeleaf.getId(), thymeleaf);
reviewList.put(htmlcss.getId(), htmlcss);
}
public ReviewSiteRepository(Review... reviews) {
for (Review review : reviews) {
reviewList.put(review.getId(), review);
}
}
public Review getOneReview(long firstTestId) {
return reviewList.get(firstTestId);
}
public Collection<Review> findAll() {
return reviewList.values();
}
public Review getOneCourse(Long id) {
return reviewList.get(id);
}
}
最后是java类:
package org.wecancodeit.reviewsite;
public class Review {
private Long Id;
private String title;
private String category;
private String image;
Review(Long id, String title, String category, String image) {
this.Id = id;
this.title = title;
this.category = category;
this.image = image;
}
public Long getId() {
return Id;
}
public String getTitle() {
return title;
}
public String getCategory() {
return category;
}
public String getImage() {
return image;
}
}
我很难弄清楚如何动态链接图像。当我运行服务器时,我得到一个错误,上面写着“在null上找不到属性或字段‘image’”。由于某种原因,图片中的thymeleaf src没有抓住我的评论。如果我硬编码在正确的路径的图像,我可以让它呈现,但它不会改变,当我去一个不同的页面
# 1 楼答案
我发现了问题
在我的控制器中,在review的请求映射下,我的属性被注入为“reviews”,而不是“review”。一封信就把整件事搞糟了,真是疯了
# 2 楼答案
不要连接。您可以使用Thymeleaf的表达式来构建URL,如下所示:
在本例中,
{image}
是一个变量,该变量的值在括号中指定:(image=thevalue)
。由于值本身是一个表达式,因此使用正则表达式语法:(image=${review.image})
它比串联要详细一点,但在URL更复杂的情况下更简洁: