提示:我们在开发过程中，尝尝需要将获取到的数据信息，以页面的形式展示给用户
目录
③调用对象和对象语法糖th:object以及内置对象和内置对象语法糖
前言： 本篇文章将从模板引擎的基础概念，模板引擎的分类讲起，着重介绍最为常见的模板引擎Thymeleaf的执行流程和使用方法。
一、模板引擎
1） 什么是模板引擎
模板引擎是为了解决用户界面（显示）与业务数据（内容）分离而产生的。他可以产生特定格式的文档，例如：HTML、XML以及其他格式的文本格式。
2） 模板引擎工作模式
3）模板引擎分类
①JSP
优点：
1.功能强大，可以写java代码。
2.支持JSP标签，（jsp.tag）
3.支持表达式语言（el表达式，jstl语法）
4.官方标准，用户多
5.性能良好，jsp编译成class文件执行，有很好的性能表现。
缺点：
没有明显缺点，使用不当会出现破坏结果
②freemarker
优点：
1.不能编写java代码，可以实现严格的mvc分离
2.性能非常不错
3.对JSP标签支持良好
4.内置大量常用功能，使用非常方便。
5.宏定义（类似jsp）
6.使用表达式语言
缺点：
1.不是官方标准
2.用户群体少
③velocit
1.不能编写java代码,可以实现严格的mvc分离
2.性能良好
3.使用表达式语言
缺点:
1.对jsp标签支持不够好
2.用户群体少,第三方标签库比jsp少
3.对jsp标签支持不够
4.很久没有维护
二、thymeleaf
1）基本概念
Thymeleaf 是新一代 Java 模板引擎，与 Velocity、FreeMarker 等传统 Java 模板引擎不同，Thymeleaf 支持 HTML 原型，其文件后缀为“.html”，因此它可以直接被浏览器打开，此时浏览器会忽略未定义的 Thymeleaf 标签属性，展示 thymeleaf 模板的静态页面效果；当通过 Web 应用程序访问时，Thymeleaf 会动态地替换掉静态内容，使页面动态显示。
2）特点
Thymeleaf 模板引擎具有以下特点：
- 动静结合：Thymeleaf 既可以直接使用浏览器打开，查看页面的静态效果，也可以通过 Web 应用程序进行访问，查看动态页面效果。
- 开箱即用：Thymeleaf 提供了 Spring 标准方言以及一个与 SpringMVC 完美集成的可选模块，可以快速的实现表单绑定、属性编辑器、国际化等功能。
- 多方言支持：它提供了 Thymeleaf 标准和 Spring 标准两种方言，可以直接套用模板实现 JSTL、 OGNL 表达式；必要时，开发人员也可以扩展和创建自定义的方言。
- 与 SpringBoot 完美整合：SpringBoot 为 Thymeleaf 提供了的默认配置，并且还为 Thymeleaf 设置了视图解析器，因此 Thymeleaf 可以与 Spring Boot 完美整合。
3）常用命令
①th:text和th:utext
- 可以对表达式或变量进行计算求值；
- 可以使用“+”进行文本拼接；
- 可以获取后端传过来的request作用域中的数据（包括Model、ModelAndView作用域）。
package com.ape.view;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
/**
* Servlet implementation class UserName
*/
@WebServlet("/UserName")
public class UserName extends HttpServlet {
private static final long serialVersionUID = 1L;
TemplateEngine templateEngine; // 模板引擎
ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//提供数据
String name = "<h1>周周</h1>";
WebContext context = new WebContext(request, response, getServletContext());
context.setVariable("username", name);
templateEngine.process("heihei", context,response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<!-- OGNL表达式 -->
<h1 th:text="${username}"></h1>
<h1 th:utext="${username}"></h1>
</body>
</html>
从上述结果我们可以看出，th:text标签是将一切内容都识别为纯文本；而th:utext标签可以识别html文本，并将其生效。
②th:src和th:switch
package com.ape.view;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
/**
* Servlet implementation class UserName
*/
@WebServlet("/UserName")
public class UserName extends HttpServlet {
private static final long serialVersionUID = 1L;
TemplateEngine templateEngine; // 模板引擎
ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//提供数据
// String name = "周周";
// String sex = "女";
int lvl=2;
WebContext context = new WebContext(request, response, getServletContext());
// context.setVariable("username", name);
// context.setVariable("sex", sex);
context.setVariable("lvl", lvl);
// templateEngine.process("yunsuanfu", context,response.getWriter());
// templateEngine.process("panduan", context,response.getWriter());
templateEngine.process("fenzhi", context,response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<div th:switch="${lvl}">
<img src="img/2.png" th:case="1">
<img src="img/3.png" th:case="2">
<img src="img/4.png" th:case="3">
<img src="img/5.png" th:case="4">
<img src="img/1.png" th:case="*">
</div>
</body>
</html>
③调用对象和对象语法糖th:object以及内置对象和内置对象语法糖
package com.ape.view;
import java.io.IOException;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
import com.ape.bean.Student;
/**
* Servlet implementation class StudentServlet
*/
@WebServlet("/StudentServlet")
public class StudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
TemplateEngine templateEngine; // 模板引擎
ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
HttpSession session = request.getSession();
//提供数据
Student s = new Student();
s.setSid(1);
s.setSname("辰 辰");
s.setBirthday(new Date());
s.setSsex("男");
session.setAttribute("stu", s);
WebContext context = new WebContext(request, response, getServletContext());
context.setVariable("student", s);
templateEngine.process("student", context,response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<span th:text="${student.sid}"></span>
<div th:text="${student.sname}"></div>
<input th:value="${student.ssex}">
<p th:text="${student.birthday}"></p>
<span th:text="${student.classid}"></span>
<!-- 获取对象数据 -->
<div th:object="${student}">
<span th:text="*{sid}"></span>
<div th:text="*{sname}"></div>
<input th:value="*{ssex}">
<p th:text="*{birthday}"></p>
<span th:text="*{classid}"></span>
</div>
<h1 th:text="${#session.getAttribute('stu')['sname']}"></h1>
<h1 th:text="${session.stu.sname}"></h1>
<!-- 调用方法 -->
<div th:text="${student.show()}"></div>
<!-- java的方法 -->
<div th:text="${student.sname.split(' ')[0]}"></div>
<div th:text="${student.sname.split(' ')[1]}"></div>
</body>
</html>
④th:action和th:href
- action是在提交表单时候可以带值到下一个页面
- href是在跳转连接时候可以带值到下一个页面
- 在下一个页面获取两者携带的值是都是通过request.getParameter(name);方法。
语法：
全查主页面
package com.ape.view;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import org.thymeleaf.context.WebContext;
import com.ape.bean.Student;
import com.ape.dao.DaoUtil;
import com.ape.mapper.StudentMapper;
/**
* Servlet implementation class findALlStudent
*/
@WebServlet("/findAllStudent")
public class findAllStudent extends BaseServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 处理乱码
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
WebContext context = new WebContext(request, response, getServletContext());
//获取数据
StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
List<Student> list = mapper.findAllStudent();
context.setVariable("stulist", list);
// 响应
templateEngine.process("showstu", context, response.getWriter());
//关闭资源
sqlSession.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
添加
package com.ape.view;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import org.thymeleaf.context.WebContext;
import com.ape.bean.Banji;
import com.ape.dao.DaoUtil;
import com.ape.mapper.BanjiMapper;
/**
* Servlet implementation class addStudentServlet
*/
@WebServlet("/addStudentServlet")
public class addStudentServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//处理乱码
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
WebContext context = new WebContext(request, response, getServletContext());
//获取数据
BanjiMapper mapper = sqlSession.getMapper(BanjiMapper.class);
List<Banji> list = mapper.findAllBanji();
context.setVariable("bjlist", list);
//响应
templateEngine.process("addstu", context, response.getWriter());
//关闭资源
sqlSession.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.ape.view;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import org.thymeleaf.context.WebContext;
import com.ape.bean.Banji;
import com.ape.dao.DaoUtil;
import com.ape.mapper.BanjiMapper;
/**
* Servlet implementation class addStudentServlet
*/
@WebServlet("/addStudentServlet")
public class addStudentServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//处理乱码
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
WebContext context = new WebContext(request, response, getServletContext());
//获取数据
BanjiMapper mapper = sqlSession.getMapper(BanjiMapper.class);
List<Banji> list = mapper.findAllBanji();
context.setVariable("bjlist", list);
//响应
templateEngine.process("addstu", context, response.getWriter());
//关闭资源
sqlSession.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
删除
package com.ape.view;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import com.ape.dao.DaoUtil;
import com.ape.mapper.StudentMapper;
/**
* Servlet implementation class delStudentServlet
*/
@WebServlet("/delStudentServlet")
public class delStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取数据
String sid = request.getParameter("sid");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
StudentMapper stumapper = sqlSession.getMapper(StudentMapper.class);
int ret = stumapper.delStudent(Integer.parseInt(sid));
//判断是否删除成功
if(ret > 0) {
sqlSession.commit();
}else {
sqlSession.rollback();
}
//重定向
response.sendRedirect("findAllStudent");
//关闭资源
DaoUtil.closeSource(sqlSession);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
修改
package com.ape.view;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import org.thymeleaf.context.WebContext;
import com.ape.bean.Banji;
import com.ape.bean.Student;
import com.ape.dao.DaoUtil;
import com.ape.mapper.BanjiMapper;
import com.ape.mapper.StudentMapper;
/**
* Servlet implementation class updateStudentServlet
*/
@WebServlet("/updateStudentServlet")
public class updateStudentServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//处理乱码
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
WebContext context = new WebContext(request, response, getServletContext());
int sid =Integer.parseInt(request.getParameter("sid"));
//获取数据
BanjiMapper mapper = sqlSession.getMapper(BanjiMapper.class);
List<Banji> list = mapper.findAllBanji();
StudentMapper mapper2 = sqlSession.getMapper(StudentMapper.class);
Student s = mapper2.findStudentBysid(sid);
context.setVariable("bjlist", list);
context.setVariable("stu", s);
//响应
templateEngine.process("updateStushow", context, response.getWriter());
//关闭资源
sqlSession.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.ape.view;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import com.ape.bean.Student;
import com.ape.dao.DaoUtil;
import com.ape.mapper.StudentMapper;
/**
* Servlet implementation class updateStudentControllerServlet
*/
@WebServlet("/updateStudentControllerServlet")
public class updateStudentControllerServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 处理乱码
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
//获取资源
SqlSession sqlSession = DaoUtil.getSqlSession();
//获取数据
int sid = Integer.parseInt(request.getParameter("sid"));
String sname = request.getParameter("sname");
String birthday = request.getParameter("birthday");
String ssex = request.getParameter("ssex");
String classid = request.getParameter("classid");
//创建对象,将数据存入对象中
Student s = new Student();
try {
s.setBirthday(sdf.parse(birthday));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
s.setSid(sid);
s.setClassid(Integer.parseInt(classid));
s.setSname(sname);
s.setSsex(ssex);
System.out.println(s);
//调用方法,将数据存入数据库
StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
int ret = mapper.updateStudent(s);
System.out.println(ret);
//判断是否修改成功,提交事务
if (ret>0) {
sqlSession.commit();
out.print("<script type=\"text/javascript\">\r\n"
+ " alert(\"修改成功\");\r\n "
+ "location.href=\"findAllStudent\";"
+ " </script>");
//重定向
//response.sendRedirect("findAllStudent");
} else {
sqlSession.rollback();
out.print("<script type=\"text/javascript\">\r\n"
+ " alert(\"修改失败\");\r\n "
+ "location.href=\"findAllStudent\";"
+ " </script>");
//重定向
//response.sendRedirect("findAllStudent");
}
//关闭资源
sqlSession.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
封装的BaseServlet
package com.ape.view;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
@WebServlet("/BaseServlet")
public class BaseServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected TemplateEngine templateEngine; // 模板引擎
protected ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
}
HTML部分
主页面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>学生列表</h1>
<table border="1">
<tr>
<th>学生编号</th>
<th>学生姓名</th>
<th>学生生日</th>
<th>学生性别</th>
<th>班级编号</th>
<th>操作</th>
</tr>
<tr th:each="item,stat : ${stulist}">
<td th:text="${stat.count}"></td>
<td th:text="${item.sname}"></td>
<td th:text="${#dates.format(item.birthday,'yyyy-MM-dd')} ?: '没有生日'"></td>
<td th:text="${item.ssex}"></td>
<td th:text="${item.classid}"></td>
<td>
<!-- th:href="@{url(key=value,key2=value2)}" -->
<a th:href="@{delStudentServlet(sid=${item.sid})}">删除</a>
<a th:href="@{updateStudentServlet(sid=${item.sid})}">修改</a>
</td>
</tr>
<tr>
<td colspan="6"><a th:href="@{addStudentServlet}">添加学生</a></td>
</tr>
</table>
</body>
</html>添加
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>添加学生</h1>
<form action="addStudentControllerServlet" method="post">
学生的姓名:<input type="text" name="sname" /><br>
学生的生日:<input type="date" name="birthday" /><br>
学生的性别:<input type="radio" name="ssex" value="男" checked />🚹
<input type="radio" name="ssex" value="女" />🚺<br>
学生的班级:<select name="classid">
<option th:each=" bj : ${bjlist}" th:value="${bj.classid}" th:text="${bj.classname}" ></option>
</select>
<br>
<input type="submit" value="添加" />
</form>
</body>
</html>修改
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>修改学生</h1>
<form action="updateStudentControllerServlet" method="post">
<input type="hidden" name="sid" th:value="${stu.sid}">
学生的姓名:<input type="text" name="sname" th:value="${stu.sname}" /><br>
学生的生日:<input type="date" name="birthday" th:value="${#dates.format(stu.birthday,'yyyy-MM-dd')}" /><br>
学生的性别:<input type="radio" name="ssex" value="男" th:checked="${stu.ssex}=='男'" />🚹
<input type="radio" name="ssex" value="女" th:checked="${stu.ssex}=='女'" />🚺<br>
学生的班级:<select name="classid">
<option th:each=" bj : ${bjlist}" th:value="${bj.classid}" th:text="${bj.classname}" th:selected="${stu.classid}==${bj.classid}" ></option>
</select>
<br>
<input type="submit" value="修改" />
</form>
</body>
</html>运行结果
点击修改学生Servlet我们可以看到跳转后修改sid=1到修改页面
⑤th:each
package com.ape.view;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.ibatis.session.SqlSession;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
import com.ape.bean.Student;
import com.ape.dao.DaoUtil;
import com.ape.mapper.StudentMapper;
/**
* Servlet implementation class StudentServlet
*/
@WebServlet("/StudentServlet")
public class StudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
TemplateEngine templateEngine; // 模板引擎
ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
SqlSession sqlSession = DaoUtil.getSqlSession();
StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
List<Student> list = mapper.findAllStudent();
WebContext context = new WebContext(request, response, getServletContext());
context.setVariable("stulist", list);
templateEngine.process("xunhuan", context,response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
.red{
background: red;
}
.blue{
background: blue;
}
</style>
</head>
<body>
<table border="2" style="border-collapse: collapse;">
<tr>
<th>序号</th>
<th>学生编号</th>
<th>学生姓名</th>
<th>学生生日</th>
<th>学生性别</th>
<th>学生班级</th>
<th>隔行变色</th>
</tr>
<tr th:each="item,stat:${stulist}" th:classappend="${stat.odd?'red':'blue'}">
<td th:text="${item.sid}"></td>
<td th:text="${stat.count}"></td>
<td th:text="${item.sname}"></td>
<td th:text="${#dates.format(item.birthday,'yyyy-MM-dd')}?:'没有生日!'"></td>
<td th:text="${item.ssex}"></td>
<td th:text="${item.classid}"></td>
<!--隔行变色(奇数为true) -->
<td th:text="${stat.odd}"></td>
</tr>
</table>
<!-- 打印到控制台 -->
<div><span style="color:red">欢迎</span>[[${stulist.get(0)}]]<span style="color:red">欢迎</span></div>
<script type="text/javascript">
alert('[[${stulist.get(2)}]]');
</script>
</body>
</html>
⑥th:if和th:unless
package com.ape.view;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
/**
* Servlet implementation class UserName
*/
@WebServlet("/UserName")
public class UserName extends HttpServlet {
private static final long serialVersionUID = 1L;
TemplateEngine templateEngine; // 模板引擎
ServletContextTemplateResolver templateResolver; //模板解析器
@Override
public void init() throws ServletException {
super.init();
templateEngine = new TemplateEngine();
templateResolver = new ServletContextTemplateResolver(getServletContext());
//设置要应用于此解析器解析的模板的模板模式。
templateResolver.setTemplateMode("HTML5");
//非严格的HTML5
// templateResolver.setTemplateMode("LEGACYHTML5");
// 设置新的字符编码以读取模板资源。
templateResolver.setCharacterEncoding("utf-8");
// 设置要添加到所有模板名称的新（可选）前缀，以将模板名称转换为资源名称。
templateResolver.setPrefix("/");
//设置要添加到所有模板名称的新（可选）后缀，以将模板名称转换为资源名称。
templateResolver.setSuffix(".html");
//将模板缓存关闭，默认是true
templateResolver.setCacheable(false);
//给模板引擎设置模板解析器
templateEngine.setTemplateResolver(templateResolver);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//提供数据
// String name = "周周";
String sex = "女";
// int lvl=2;
WebContext context = new WebContext(request, response, getServletContext());
context.setVariable("username", name);
context.setVariable("sex", sex);
// context.setVariable("lvl", lvl);
// templateEngine.process("yunsuanfu", context,response.getWriter());
templateEngine.process("panduan", context,response.getWriter());
// templateEngine.process("fenzhi", context,response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<!-- 条件成立选择 -->
<div th:if = "${sex}=='男'">
<input type="radio" name="sex" value="男" checked="checked">男
<input type="radio" name="sex" value="女">女
</div>
<div th:if = "${sex}=='女'">
<input type="radio" name="sex" value="男">男
<input type="radio" name="sex" value="女" checked="checked">女
</div>
<!-- 条件成立不选择 -->
<div th:unless = "${sex}=='男'">
<input type="radio" name="sex" value="男" checked="checked">男
<input type="radio" name="sex" value="女">女
</div>
<div th:unless = "${sex}=='女'">
<input type="radio" name="sex" value="男">男
<input type="radio" name="sex" value="女" checked="checked">女
</div>
</body>
</html>
大家可以看到if为满足条件则运行并且显示HTML，unless为不满足条件时候执行，两者显示完成后继续执行if和unless并且后面显示结果会覆盖前面条件，所以看到的运行结果为第二行选中男选项。
又是新的一周！加油宝子们！下个阶段的学习继续努力啊！！！