SpringBoot的Restful CRUD
1. 首先,讓我們看一下Restful Api的基礎知識
2.在SpringBoot中,關於Restful API的使用,主要包含以下幾個內容:
- 1)通過自定義MvcConfig來定義預設訪問頁面
2)國際化
3)攔截器配置,用於對登入使用者進行檢查
4)Rest風格的CRUD實現(模板引擎使用ThemeLeaf)
1)、通過自定義MvcConfig來定義預設訪問頁面
//使用WebMvcConfigurerAdapter可以來擴充套件SpringMVC的功能 //@EnableWebMvc 不要接管SpringMVC @Configuration public class MyMvcConfig extends WebMvcConfigurerAdapter { @Override public void addViewControllers(ViewControllerRegistry registry) { // super.addViewControllers(registry); //瀏覽器傳送 /atguigu 請求來到 success registry.addViewController("/atguigu").setViewName("success"); } //所有的WebMvcConfigurerAdapter元件都會一起起作用 @Bean //將元件註冊在容器 public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){ WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() { @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); } }; return adapter; } }
2)、國際化
1)、編寫國際化配置檔案;
2)、使用ResourceBundleMessageSource管理國際化資原始檔
3)、在頁面使用fmt:message取出國際化內容
步驟:
1)、編寫國際化配置檔案,抽取頁面需要顯示的國際化訊息
2)、SpringBoot自動配置好了管理國際化資原始檔的元件;
@ConfigurationProperties(prefix = "spring.messages") public class MessageSourceAutoConfiguration { /** * Comma-separated list of basenames (essentially a fully-qualified classpath * location), each following the ResourceBundle convention with relaxed support for * slash based locations. If it doesn't contain a package qualifier (such as * "org.mypackage"), it will be resolved from the classpath root. */ private String basename = "messages"; //我們的配置檔案可以直接放在類路徑下叫messages.properties; @Bean public MessageSource messageSource() { ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource(); if (StringUtils.hasText(this.basename)) { //設定國際化資原始檔的基礎名(去掉語言國家程式碼的) messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray( StringUtils.trimAllWhitespace(this.basename))); } if (this.encoding != null) { messageSource.setDefaultEncoding(this.encoding.name()); } messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale); messageSource.setCacheSeconds(this.cacheSeconds); messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat); return messageSource; }
3)、去頁面獲取國際化的值;
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"> <meta name="description" content=""> <meta name="author" content=""> <title>Signin Template for Bootstrap</title> <!-- Bootstrap core CSS --> <link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet"> <!-- Custom styles for this template --> <link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet"> </head> <body class="text-center"> <form class="form-signin" action="dashboard.html"> <img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72"> <h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1> <label class="sr-only" th:text="#{login.username}">Username</label> <input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus=""> <label class="sr-only" th:text="#{login.password}">Password</label> <input type="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required=""> <div class="checkbox mb-3"> <label> <input type="checkbox" value="remember-me"/> [[#{login.remember}]] </label> </div> <button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign in</button> <p class="mt-5 mb-3 text-muted">© 2017-2018</p> <a class="btn btn-sm">中文</a> <a class="btn btn-sm">English</a> </form> </body> </html>
效果:根據瀏覽器語言設定的資訊切換了國際化;
原理:
國際化Locale(區域資訊物件);LocaleResolver(獲取區域資訊物件);
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
public LocaleResolver localeResolver() {
if (this.mvcProperties
.getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
return new FixedLocaleResolver(this.mvcProperties.getLocale());
}
AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
return localeResolver;
}
預設的就是根據請求頭帶來的區域資訊獲取Locale進行國際化
4)、點選連結切換國際化
/**
* 可以在連線上攜帶區域資訊
*/
public class MyLocaleResolver implements LocaleResolver {
@Override
public Locale resolveLocale(HttpServletRequest request) {
String l = request.getParameter("l");
Locale locale = Locale.getDefault();
if(!StringUtils.isEmpty(l)){
String[] split = l.split("_");
locale = new Locale(split[0],split[1]);
}
return locale;
}
@Override
public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
}
}
@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}
3)、登陸
開發期間模板引擎頁面修改以後,要實時生效
1)、禁用模板引擎的快取
# 禁用快取
spring.thymeleaf.cache=false
2)、頁面修改完成以後ctrl+f9:重新編譯;
登陸錯誤訊息的顯示
<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
4)、攔截器進行登陸檢查
攔截器
/**
* 登陸檢查,
*/
public class LoginHandlerInterceptor implements HandlerInterceptor {
//目標方法執行之前
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
Object user = request.getSession().getAttribute("loginUser");
if(user == null){
//未登陸,返回登陸頁面
request.setAttribute("msg","沒有許可權請先登陸");
request.getRequestDispatcher("/index.html").forward(request,response);
return false;
}else{
//已登陸,放行請求
return true;
}
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
}
}
註冊攔截器
//所有的WebMvcConfigurerAdapter元件都會一起起作用
@Bean //將元件註冊在容器
public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
registry.addViewController("/main.html").setViewName("dashboard");
}
//註冊攔截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
//super.addInterceptors(registry);
//靜態資源; *.css , *.js
//SpringBoot已經做好了靜態資源對映
registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
.excludePathPatterns("/index.html","/","/user/login");
}
};
return adapter;
}
5)、CRUD-員工列表
Restful方式的前後端互動格式要求:
3)、員工列表:
thymeleaf公共頁面元素抽取
1、抽取公共片段
<div th:fragment="copy">
© 2011 The Good Thymes Virtual Grocery
</div>
2、引入公共片段
<div th:insert="~{footer :: copy}"></div>
~{templatename::selector}:模板名::選擇器
~{templatename::fragmentname}:模板名::片段名
3、預設效果:
insert的公共片段在div標籤中
如果使用th:insert等屬性進行引入,可以不用寫~{}:
行內寫法可以加上:[[~{}]];[(~{})];
三種引入公共片段的th屬性:
th:insert:將公共片段整個插入到宣告引入的元素中
th:replace:將宣告引入的元素替換為公共片段
th:include:將被引入的片段的內容包含進這個標籤中
<footer th:fragment="copy">
© 2011 The Good Thymes Virtual Grocery
</footer>
引入方式
<div th:insert="footer :: copy"></div>
<div th:replace="footer :: copy"></div>
<div th:include="footer :: copy"></div>
效果
<div>
<footer>
© 2011 The Good Thymes Virtual Grocery
</footer>
</div>
<footer>
© 2011 The Good Thymes Virtual Grocery
</footer>
<div>
© 2011 The Good Thymes Virtual Grocery
</div>
引入片段的時候傳入引數:
<nav class="col-md-2 d-none d-md-block bg-light sidebar" id="sidebar">
<div class="sidebar-sticky">
<ul class="nav flex-column">
<li class="nav-item">
<a class="nav-link active"
th:class="${activeUri=='main.html'?'nav-link active':'nav-link'}"
href="#" th:href="@{/main.html}">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-home">
<path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path>
<polyline points="9 22 9 12 15 12 15 22"></polyline>
</svg>
Dashboard <span class="sr-only">(current)</span>
</a>
</li>
<!--引入側邊欄;傳入引數-->
<div th:replace="commons/bar::#sidebar(activeUri='emps')"></div>
6)、CRUD-員工新增
新增頁面
<form>
<div class="form-group">
<label>LastName</label>
<input type="text" class="form-control" placeholder="zhangsan">
</div>
<div class="form-group">
<label>Email</label>
<input type="email" class="form-control" placeholder="[email protected]">
</div>
<div class="form-group">
<label>Gender</label><br/>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="1">
<label class="form-check-label">男</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="0">
<label class="form-check-label">女</label>
</div>
</div>
<div class="form-group">
<label>department</label>
<select class="form-control">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
<option>5</option>
</select>
</div>
<div class="form-group">
<label>Birth</label>
<input type="text" class="form-control" placeholder="zhangsan">
</div>
<button type="submit" class="btn btn-primary">新增</button>
</form>
提交的資料格式不對:生日:日期;
2017-12-12;2017/12/12;2017.12.12;
日期的格式化;SpringMVC將頁面提交的值需要轉換為指定的型別;
2017-12-12—Date; 型別轉換,格式化;
預設日期是按照/的方式;
7)、CRUD-員工修改
修改新增二合一表單
<!--需要區分是員工修改還是新增;-->
<form th:action="@{/emp}" method="post">
<!--傳送put請求修改員工資料-->
<!--
1、SpringMVC中配置HiddenHttpMethodFilter;(SpringBoot自動配置好的)
2、頁面建立一個post表單
3、建立一個input項,name="_method";值就是我們指定的請求方式
-->
<input type="hidden" name="_method" value="put" th:if="${emp!=null}"/>
<input type="hidden" name="id" th:if="${emp!=null}" th:value="${emp.id}">
<div class="form-group">
<label>LastName</label>
<input name="lastName" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${emp.lastName}">
</div>
<div class="form-group">
<label>Email</label>
<input name="email" type="email" class="form-control" placeholder="[email protected]" th:value="${emp!=null}?${emp.email}">
</div>
<div class="form-group">
<label>Gender</label><br/>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="1" th:checked="${emp!=null}?${emp.gender==1}">
<label class="form-check-label">男</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="0" th:checked="${emp!=null}?${emp.gender==0}">
<label class="form-check-label">女</label>
</div>
</div>
<div class="form-group">
<label>department</label>
<!--提交的是部門的id-->
<select class="form-control" name="department.id">
<option th:selected="${emp!=null}?${dept.id == emp.department.id}" th:value="${dept.id}" th:each="dept:${depts}" th:text="${dept.departmentName}">1</option>
</select>
</div>
<div class="form-group">
<label>Birth</label>
<input name="birth" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${#dates.format(emp.birth, 'yyyy-MM-dd HH:mm')}">
</div>
<button type="submit" class="btn btn-primary" th:text="${emp!=null}?'修改':'新增'">新增</button>
</form>
8)、CRUD-員工刪除
<tr th:each="emp:${emps}">
<td th:text="${emp.id}"></td>
<td>[[${emp.lastName}]]</td>
<td th:text="${emp.email}"></td>
<td th:text="${emp.gender}==0?'女':'男'"></td>
<td th:text="${emp.department.departmentName}"></td>
<td th:text="${#dates.format(emp.birth, 'yyyy-MM-dd HH:mm')}"></td>
<td>
<a class="btn btn-sm btn-primary" th:href="@{/emp/}+${emp.id}">編輯</a>
<button th:attr="[email protected]{/emp/}+${emp.id}" class="btn btn-sm btn-danger deleteBtn">刪除</button>
</td>
</tr>
<script>
$(".deleteBtn").click(function(){
//刪除當前員工的
$("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit();
return false;
});
</script>
補充:
1.ThemeLeaf的預設配置路徑
ThemeLeaf的預設配置路徑通過閱讀原始碼中的 themeleaf.properties可以看出,路徑為:classpath:/templates/,字尾是 .html
2.攔截器的配置:
在Spring中,我們在web.xml中用xml配置Interceptor,而在SpringBoot中,我們使用繼承了WebMvcConfigurerAdapter的自定義類註冊自定義的Interceptor,實現訪問過濾。
//使用WebMvcConfigurerAdapter可以來擴充套件SpringMVC的功能
//@EnableWebMvc 不要接管SpringMVC
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//瀏覽器傳送 /atguigu 請求來到 success
registry.addViewController("/atguigu").setViewName("success");
}
//所有的WebMvcConfigurerAdapter元件都會一起起作用
@Bean //將元件註冊在容器
public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
registry.addViewController("/main.html").setViewName("dashboard");
}
//註冊攔截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
//super.addInterceptors(registry);
//靜態資源; *.css , *.js
//SpringBoot已經做好了靜態資源對映
// registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
// .excludePathPatterns("/index.html","/","/user/login");
}
};
return adapter;
}
@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}