Spring Boot Starter Series six (Springboot integrated thymeleaf)

Springboot Integration Thymeleaf One, what is the thymeleaf template

Thymeleaf is a template engine for rendering XML/XHTML/HTML5 content. Like Jsp,velocity,freemaker, it can also be easily integrated with web frameworks such as spring MVC as a template engine for Web applications. The biggest feature of thymeleaf compared to other template engines is the ability to open and correctly display template pages directly in the browser without having to launch the entire web app. It features the following functions:

• The method in the @Controller can return the template name directly, and then the Thymeleaf template engine will render automatically

• Expressions in templates support Spring expression language (Spring EL)

• Forms support and compatibility with spring MVC's data binding and validation mechanisms

• Internationalization support

Spring officials also recommend using Thymeleaf, so this code integration uses Thymeleaf to integrate.

Ii. Development Step 1, introducing dependency in Maven

<!--hot deployment--><dependency>    <groupId>org.springframework.boot</groupId>    < Artifactid>spring-boot-devtools</artifactid>    <optional>true</optional></dependency >

2. Configure the Thymeleaf template in the configuration file application.properties

Spring-boot configuration file thymeleaf template configuration items (Common configuration items are red） Parameters Introduction Spring.thymeleaf.cache = True Enable template caching (recommended when development is off) Spring.thymeleaf.check-template = True Checks if the template exists and then renders Spring.thymeleaf.check-template-location = True Check if template location exists Spring.thymeleaf.content-type = text/html Content-type value Spring.thymeleaf.enabled = True Enable MVC Thymeleaf View Resolution spring.thymeleaf.encoding = UTF-8 Template encoding Spring.thymeleaf.excluded-view-names = Comma-delimited list of view names that should be excluded from the solution Spring.thymeleaf.mode = HTML5 Template mode applied to the template. See also Standardtemplatemodehandlers Spring.thymeleaf.prefix = classpath:/templates/ Pre-view prefix of names when building URLs Spring.thymeleaf.suffix =. html Append view name suffix when building URLs Spring.thymeleaf.template-resolver-order = The order of the template parsers in the chain Spring.thymeleaf.view-names = Comma-separated list of view names that can be resolved

##################################    thymeleaf template ################################ #应用于模板的模板模式. See also standardtemplatemodehandlersspring.thymeleaf.mode=html5# template encoding spring.thymeleaf.encoding=utf-8# Content-type value spring.thymeleaf.content-type=text/html# Turn off caching when developing, or you won't be able to see live pages spring.thymeleaf.cache=false# Pre-view the name prefix when building the URL Spring.thymeleaf.prefix = classpath:/templates/#构建URL时附加查看名称的后缀spring. Thymeleaf.suffix =. html

3. Create Thymeleaf template file, add folder Thymeleaf in template, and add index.html in new folder to display data returned by controller

<! DOCTYPE html>
　　
4. Added Thymeleafcontroller.java in controller to return data to the front end
@Controller @requestmapping ("/thymeleaf") public class Thymeleafcontroller {    /**     * Test thymeleaf     * @return     */    @RequestMapping ("/index") public    String Hello (model model) {        Model.addattribute ("name", "Dear") ;        return "/thymeleaf/index";    }}
　　
5. Testing
　　
　　
Third, the basic grammar of Thymeleaf
Aftertaste above the demo, you can see the first to rewrite the HTML tag
In this way, you can use this syntax in other tags th:* . This is the premise of the following syntax .
1. Get the value of a variable
<p th:text= "' hello! , ' + ${name} + '! ' >3333</p>
It can be seen that getting the value of a variable $ is used as a symbol for JavaBean, 变量名.属性名 which is the same as an El expression.
In addition, the $ expression can only be written inside the th tag, otherwise it will not take effect, the above example is to use the value of the th:text label to replace the p value inside the label, as for the original value of P is only for the front-end development of the display used. This is good to do before and after the end of the separation.
2. Introduction of URLs
Thymeleaf for URL processing is through syntax @{...} To deal with.
<a th:href= "@{http://blog.csdn.net/u012706811}" > Absolute path </a><a th:href= "@{/}" > Relative path </a><a th:href= "@{css/bootstrap.min.css}" >content path, default access to the CSS folder under static </a>
Similar tags are: th:href andth:src
3. String substitution
Most of the time, we just need to replace a place in a large paragraph of text, which can be done with a string concatenation operation:
<span th:text= "' Welcome to our application, ' + ${user.name} + '! '" >
A more concise approach is to:
<span th:text= "| Welcome to our application, ${user.name}!| " >
Of course, this form is more restrictive, |...| Can only contain variable expressions ${...}, cannot contain other constants, conditional expressions, and so on.
4. Operators
You can use various arithmetic operators in an expression, such as +,-, *,/,%
Th:with= "iseven= (${prodstat.count}% 2 = = 0)"
logical operators, <, <=,>=,==,!= are all available, the only thing to note is the HTML escape character that needs to be used with <,>:
th:if= "${prodstat.count} > 1" th:text= "' execution mode is ' + ((${execmode} = = ' dev ')? ' Development ': ' Production ') "
5. Conditions
If/unless
The thymeleaf uses the th:if and th:unless attributes for conditional judgment, and in the following example, the label is only displayed when the condition in the Th:if is true:
<a th:href= "@{/login}" Th:unless=${session.user! = null}>login</a>
Th:unless is the opposite of th:if, the content is displayed only if the condition in the expression is not true.
Switch
Thymeleaf also supports multi-select switch structures:
<div th:switch= "${user.role}" >  <p th:case= "' admin '" >user is an administrator</p>  <p th: Case= "#{roles.manager}" >user is a manager</p></div>
Default property defaults can be represented by *:
<div th:switch= "${user.role}" >  <p th:case= "' admin '" >user is an administrator</p>  <p th: Case= "#{roles.manager}" >user is a manager</p>  <p th:case= "*" >user are some other thing</p>< /div>
6. Cycle
Rendering list data is a very common scenario, for example, now that there are N records that need to be rendered into a table, the data set must be traversed, using the Th:each tag:
<body>  
As you can see, you need to include the Th:each tag in the loop-rendered element (here), where th:each= "prod: ${prods}" means iterating over the set variable prods, which is prod in the loop body that can be accessed through an expression.
7.Utilities
For easier template use, Thymeleaf also provides a series of utility objects (built into the context) that can be accessed directly via #:

 
    

  
     
 
      
#dates
 
      
#calendars
 
      
#numbers
 
      
#strings
 
      
Arrays
 
      
Lists
 
      
Sets
 
      
Maps
 
      
...
Here is a snippet of code to illustrate some common methods:
 
     
 
    
Date
/* * Format date with the specified pattern * Also works with arrays, lists or sets */${#dates. Format (date, ' dd/mmm/yyyy H h:mm ')}${#dates. Arrayformat (Datesarray, ' dd/mmm/yyyy hh:mm ')}${#dates. ListFormat (dateslist, ' dd/mmm/yyyy HH:mm ')}$ {#dates. SetFormat (Datesset, ' dd/mmm/yyyy hh:mm ')}/* * Create a date (Java.util.Date) object for the current date and time */${#dates. Createnow ()}/* * Create a date (Java.util.Date) object for the current date (time set to 00:00) */${#dates. Crea Tetoday ()}
String
/* * Check whether a String is empty (or null). Performs a trim () operation before check * Also works with arrays, lists or sets */${#strings. IsEmpty (name)}${#strings. arr Ayisempty (Namearr)}${#strings. Listisempty (namelist)}${#strings. Setisempty (nameset)}/* * Check whether a String Starts or ends with a fragment * Also works with arrays, lists or sets */${#strings. StartsWith (name, ' Don ')}                  //Also AR  ray*, list* and set*${#strings. EndsWith (name,endingfragment)}           //also array*, list* and set*/* * Compute length * Also Works with arrays, lists or sets */${#strings. Length (str)}/* * Null-safe comparison and concatenation */${#strings. equals (str)} ${#strings. Equalsignorecase (str)}${#strings. concat (str)}${#strings. Concatreplacenulls (str)}/* * Random */${# Strings.randomalphanumeric (Count)}
Supplement
After spring-boot1.4, support for THYMELEAF3, you can change the version number for modification support.
3 compared to 2 greatly improves the efficiency, and does not need the label closure, similar link,img and so on has the very good support, according to the following configuration can
<properties>    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>    < !--set Thymeleaf version--    <thymeleaf.version>3.0.0.RELEASE</thymeleaf.version>    < Thymeleaf-layout-dialect.version>2.0.0</thymeleaf-layout-dialect.version>    <!--set Java version-- >    <java.version>1.8</java.version>  </properties>
　　
Spring Boot Starter Series six (Springboot integrated thymeleaf)