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JavaWeb学习-Thymeleaf

作者:互联网

Thymeleaf:视图模板技术

Thymeleaf是一个供后端人员使用的,为快速开发页面而生的Java模板引擎,能够动态地替换掉静态内容,使页面动态显示。

(模板引擎(用于Web开发)是为了使用户界面与业务数据(内容)分离而产生的,它可以生成特定格式的文档,用于网站的模板引擎就会生成一个标准的HTML文档。)

(1)添加JAR包

(2)新建一个Servlet类ViewBaseServlet

import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ViewBaseServlet extends HttpServlet {

    private TemplateEngine templateEngine;

    @Override
    public void init() throws ServletException {

        // 1.获取ServletContext对象
        ServletContext servletContext = this.getServletContext();

        // 2.创建Thymeleaf解析器对象
        ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(servletContext);

        // 3.给解析器对象设置参数
        // ①HTML是默认模式,明确设置是为了代码更容易理解
        templateResolver.setTemplateMode(TemplateMode.HTML);

        // ②设置前缀
        String viewPrefix = servletContext.getInitParameter("view-prefix");

        templateResolver.setPrefix(viewPrefix);

        // ③设置后缀
        String viewSuffix = servletContext.getInitParameter("view-suffix");

        templateResolver.setSuffix(viewSuffix);

        // ④设置缓存过期时间(毫秒)
        templateResolver.setCacheTTLMs(60000L);

        // ⑤设置是否缓存
        templateResolver.setCacheable(true);

        // ⑥设置服务器端编码方式
        templateResolver.setCharacterEncoding("utf-8");

        // 4.创建模板引擎对象
        templateEngine = new TemplateEngine();

        // 5.给模板引擎对象设置模板解析器
        templateEngine.setTemplateResolver(templateResolver);

    }

    protected void processTemplate(String templateName, HttpServletRequest req, HttpServletResponse resp) throws IOException {
        // 1.设置响应体内容类型和字符集
        resp.setContentType("text/html;charset=UTF-8");

        // 2.创建WebContext对象
        WebContext webContext = new WebContext(req, resp, getServletContext());

        // 3.处理模板数据
        templateEngine.process(templateName, webContext, resp.getWriter());
    }
}

(3)在web.xml中添加配置

<!-- 在上下文参数中配置视图前缀和视图后缀 -->
<context-param>
    <param-name>view-prefix</param-name>
    <param-value>/</param-value>
</context-param>
<context-param>
    <param-name>view-suffix</param-name>
    <param-value>.html</param-value>
</context-param>

(4)我们的Servlet继承ViewBaseServlet

根据逻辑视图获得真实视图名称


@WebServlet("/index")
public class IndexServlet extends ViewBaseServlet {
    protected void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {
        FruitDAO fruitDAO = new FruitDAOImpl();
        List<Fruit> fruitList = fruitDAO.getFruitList();
        System.out.println("fruitList.size() = " + fruitList.size());
        HttpSession session = request.getSession();
        session.setAttribute("fruitList",fruitList);

        Object fr = session.getAttribute("fruitList");
        System.out.println("fr = " + fr);


        //处理模板(视图名称,request,response)
        //thymeleaf 会将这个逻辑视图名称对应到物理视图名称上去,
        //逻辑视图名称:  index
        //物理视图名称:  view-prefix + 逻辑视图名称 + view-suffix
        //真实视图名称:       /           index        .html
        super.processTemplate("index",request,response);
    }
}

(5)页面使用Thymeleaf标签获取数据

<div>
    <table>
        <tr>
            <th>名称</th>
            <th>单价</th>
            <th>数量</th>
            <th>备注</th>
        </tr>
        <tr th:if="${#lists.isEmpty(session.fruitList)}"><!--判断集合是否为空-->
            <td>库存为空!</td><!--为空输出语句-->
        </tr>
        <tr th:unless="${#lists.isEmpty(session.fruitList)}" th:each="fruit : ${session.fruitList}">
            <!--集合不为空,循环输出-->
            <td th:text="${fruit.fname}"></td>
            <td th:text="${fruit.price}"></td>
            <td th:text="${fruit.fcount}"></td>
            <td th:text="${fruit.remark}"></td>
        </tr>
    </table>
</div>

标签:JavaWeb,templateResolver,视图,学习,Thymeleaf,import,servlet,javax,模板
来源: https://www.cnblogs.com/Joyce-mi7/p/16481131.html