thymeleaf功能详解

我会带着你远行 2022-12-08 14:28 552阅读 0赞

一.简单表达格式:   [thymeleaf的官方参考文档][thymeleaf]

1.变量的表达式：$\{...\}

2.选择变量表达式：\*\{...\}

3.信息表达:\#\{...\}

4.链接URL表达式:@\{...\}

二.字面值

1.文本文字：`'one text'`, `'Another one!'`,…

2.文字数量：`0`, `34`, `3.0`, `12.3`,…

3.布尔型常量：`true`, `false`

4.空的文字：null

5.文字标记：`one`, `sometext`, `main`,…

四：文本处理

1.字符串并置：+

2.文字替换：|The name is $\{name\}|

五.表达基本对象

1.\#ctx:上下文对象

2.\#vars:上下文变量

3.\#locale:上下文语言环境

4.\#httpServletRequest:(只有在Web上下文)HttpServletRequest对象

5.\#httpSession:(只有在Web上下文)HttpSession对象。

用法：

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>&lt;</code><code>span</code>&nbsp;<code>th:text="${#locale.country}"&gt;US&lt;/</code><code>span</code><code>&gt;.</code></p> </td> 
  </tr> 
 </tbody> 
</table>

六.实用表达对象

*  `#dates`: java.util的实用方法。对象:日期格式、组件提取等.
 *  `#calendars`: 类似于\#日期,但对于java.util。日历对象
 *  `#numbers`: 格式化数字对象的实用方法。
 *  `#strings`:字符串对象的实用方法:包含startsWith,将/附加等。
 *  `#objects`: 实用方法的对象。
 *  `#bools`: 布尔评价的实用方法。
 *  `#arrays`: 数组的实用方法。
 *  `#lists`: list集合。
 *  `#sets`:set集合。
 *  `#maps`: map集合。
 *  `#aggregates`: 实用程序方法用于创建聚集在数组或集合.
 *  `#messages`: 实用程序方法获取外部信息内部变量表达式,以同样的方式,因为他们将获得使用\# \{…\}语法
 *  `#ids`: 实用程序方法来处理可能重复的id属性(例如,由于迭代)。

Dates
    
    #dates : utility methods for java.util.Date objects:
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Dates
     * ======================================================================
     */
    
    /*
     * Null-safe toString()
     */
    ${#strings.toString(obj)}                           // also array*, list* and set*
    
    /*
     * Format date with the standard locale format
     * Also works with arrays, lists or sets
     */
    ${#dates.format(date)}
    ${#dates.arrayFormat(datesArray)}
    ${#dates.listFormat(datesList)}
    ${#dates.setFormat(datesSet)}
    
    /*
     * Format date with the specified pattern
     * Also works with arrays, lists or sets
     */
    ${#dates.format(date, 'dd/MMM/yyyy HH: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')}
    
    /*
     * Obtain date properties
     * Also works with arrays, lists or sets
     */
    ${#dates.day(date)}                    // also arrayDay(...), listDay(...), etc.
    ${#dates.month(date)}                  // also arrayMonth(...), listMonth(...), etc.
    ${#dates.monthName(date)}              // also arrayMonthName(...), listMonthName(...), etc.
    ${#dates.monthNameShort(date)}         // also arrayMonthNameShort(...), listMonthNameShort(...), etc.
    ${#dates.year(date)}                   // also arrayYear(...), listYear(...), etc.
    ${#dates.dayOfWeek(date)}              // also arrayDayOfWeek(...), listDayOfWeek(...), etc.
    ${#dates.dayOfWeekName(date)}          // also arrayDayOfWeekName(...), listDayOfWeekName(...), etc.
    ${#dates.dayOfWeekNameShort(date)}     // also arrayDayOfWeekNameShort(...), listDayOfWeekNameShort(...), etc.
    ${#dates.hour(date)}                   // also arrayHour(...), listHour(...), etc.
    ${#dates.minute(date)}                 // also arrayMinute(...), listMinute(...), etc.
    ${#dates.second(date)}                 // also arraySecond(...), listSecond(...), etc.
    ${#dates.millisecond(date)}            // also arrayMillisecond(...), listMillisecond(...), etc.
    
    /*
     * Create date (java.util.Date) objects from its components
     */
    ${#dates.create(year,month,day)}
    ${#dates.create(year,month,day,hour,minute)}
    ${#dates.create(year,month,day,hour,minute,second)}
    ${#dates.create(year,month,day,hour,minute,second,millisecond)}
    
    /*
     * 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.createToday()}
    Calendars
    
    #calendars : analogous to #dates, but for java.util.Calendar objects:
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Calendars
     * ======================================================================
     */
    
    /*
     * Format calendar with the standard locale format
     * Also works with arrays, lists or sets
     */
    ${#calendars.format(cal)}
    ${#calendars.arrayFormat(calArray)}
    ${#calendars.listFormat(calList)}
    ${#calendars.setFormat(calSet)}
    
    /*
     * Format calendar with the specified pattern
     * Also works with arrays, lists or sets
     */
    ${#calendars.format(cal, 'dd/MMM/yyyy HH:mm')}
    ${#calendars.arrayFormat(calArray, 'dd/MMM/yyyy HH:mm')}
    ${#calendars.listFormat(calList, 'dd/MMM/yyyy HH:mm')}
    ${#calendars.setFormat(calSet, 'dd/MMM/yyyy HH:mm')}
    
    /*
     * Obtain calendar properties
     * Also works with arrays, lists or sets
     */
    ${#calendars.day(date)}                // also arrayDay(...), listDay(...), etc.
    ${#calendars.month(date)}              // also arrayMonth(...), listMonth(...), etc.
    ${#calendars.monthName(date)}          // also arrayMonthName(...), listMonthName(...), etc.
    ${#calendars.monthNameShort(date)}     // also arrayMonthNameShort(...), listMonthNameShort(...), etc.
    ${#calendars.year(date)}               // also arrayYear(...), listYear(...), etc.
    ${#calendars.dayOfWeek(date)}          // also arrayDayOfWeek(...), listDayOfWeek(...), etc.
    ${#calendars.dayOfWeekName(date)}      // also arrayDayOfWeekName(...), listDayOfWeekName(...), etc.
    ${#calendars.dayOfWeekNameShort(date)} // also arrayDayOfWeekNameShort(...), listDayOfWeekNameShort(...), etc.
    ${#calendars.hour(date)}               // also arrayHour(...), listHour(...), etc.
    ${#calendars.minute(date)}             // also arrayMinute(...), listMinute(...), etc.
    ${#calendars.second(date)}             // also arraySecond(...), listSecond(...), etc.
    ${#calendars.millisecond(date)}        // also arrayMillisecond(...), listMillisecond(...), etc.
    
    /*
     * Create calendar (java.util.Calendar) objects from its components
     */
    ${#calendars.create(year,month,day)}
    ${#calendars.create(year,month,day,hour,minute)}
    ${#calendars.create(year,month,day,hour,minute,second)}
    ${#calendars.create(year,month,day,hour,minute,second,millisecond)}
    
    /*
     * Create a calendar (java.util.Calendar) object for the current date and time
     */
    ${#calendars.createNow()}
    
    /*
     * Create a calendar (java.util.Calendar) object for the current date (time set to 00:00)
     */
    ${#calendars.createToday()}
    Numbers
    
    #numbers : utility methods for number objects:
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Numbers
     * ======================================================================
     */
    
    /*
     * ==========================
     * Formatting integer numbers
     * ==========================
     */
    
    /* 
     * Set minimum integer digits.
     * Also works with arrays, lists or sets
     */
    ${#numbers.formatInteger(num,3)}
    ${#numbers.arrayFormatInteger(numArray,3)}
    ${#numbers.listFormatInteger(numList,3)}
    ${#numbers.setFormatInteger(numSet,3)}
    
    
    /* 
     * Set minimum integer digits and thousands separator: 
     * 'POINT', 'COMMA', 'NONE' or 'DEFAULT' (by locale).
     * Also works with arrays, lists or sets
     */
    ${#numbers.formatInteger(num,3,'POINT')}
    ${#numbers.arrayFormatInteger(numArray,3,'POINT')}
    ${#numbers.listFormatInteger(numList,3,'POINT')}
    ${#numbers.setFormatInteger(numSet,3,'POINT')}
    
    
    /*
     * ==========================
     * Formatting decimal numbers
     * ==========================
     */
    
    /*
     * Set minimum integer digits and (exact) decimal digits.
     * Also works with arrays, lists or sets
     */
    ${#numbers.formatDecimal(num,3,2)}
    ${#numbers.arrayFormatDecimal(numArray,3,2)}
    ${#numbers.listFormatDecimal(numList,3,2)}
    ${#numbers.setFormatDecimal(numSet,3,2)}
    
    /*
     * Set minimum integer digits and (exact) decimal digits, and also decimal separator.
     * Also works with arrays, lists or sets
     */
    ${#numbers.formatDecimal(num,3,2,'COMMA')}
    ${#numbers.arrayFormatDecimal(numArray,3,2,'COMMA')}
    ${#numbers.listFormatDecimal(numList,3,2,'COMMA')}
    ${#numbers.setFormatDecimal(numSet,3,2,'COMMA')}
    
    /*
     * Set minimum integer digits and (exact) decimal digits, and also thousands and 
     * decimal separator.
     * Also works with arrays, lists or sets
     */
    ${#numbers.formatDecimal(num,3,'POINT',2,'COMMA')}
    ${#numbers.arrayFormatDecimal(numArray,3,'POINT',2,'COMMA')}
    ${#numbers.listFormatDecimal(numList,3,'POINT',2,'COMMA')}
    ${#numbers.setFormatDecimal(numSet,3,'POINT',2,'COMMA')}
    
    
    
    /*
     * ==========================
     * Utility methods
     * ==========================
     */
    
    /*
     * Create a sequence (array) of integer numbers going
     * from x to y
     */
    ${#numbers.sequence(from,to)}
    ${#numbers.sequence(from,to,step)}
    Strings
    
    #strings : utility methods for String objects:
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Strings
     * ======================================================================
     */
    
    /*
     * 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.arrayIsEmpty(nameArr)}
    ${#strings.listIsEmpty(nameList)}
    ${#strings.setIsEmpty(nameSet)}
    
    /*
     * Perform an 'isEmpty()' check on a string and return it if false, defaulting to
     * another specified string if true.
     * Also works with arrays, lists or sets
     */
    ${#strings.defaultString(text,default)}
    ${#strings.arrayDefaultString(textArr,default)}
    ${#strings.listDefaultString(textList,default)}
    ${#strings.setDefaultString(textSet,default)}
    
    /*
     * Check whether a fragment is contained in a String
     * Also works with arrays, lists or sets
     */
    ${#strings.contains(name,'ez')}                     // also array*, list* and set*
    ${#strings.containsIgnoreCase(name,'ez')}           // also array*, list* and set*
    
    /*
     * Check whether a String starts or ends with a fragment
     * Also works with arrays, lists or sets
     */
    ${#strings.startsWith(name,'Don')}                  // also array*, list* and set*
    ${#strings.endsWith(name,endingFragment)}           // also array*, list* and set*
    
    /*
     * Substring-related operations
     * Also works with arrays, lists or sets
     */
    ${#strings.indexOf(name,frag)}                      // also array*, list* and set*
    ${#strings.substring(name,3,5)}                     // also array*, list* and set*
    ${#strings.substringAfter(name,prefix)}             // also array*, list* and set*
    ${#strings.substringBefore(name,suffix)}            // also array*, list* and set*
    ${#strings.replace(name,'las','ler')}               // also array*, list* and set*
    
    /*
     * Append and prepend
     * Also works with arrays, lists or sets
     */
    ${#strings.prepend(str,prefix)}                     // also array*, list* and set*
    ${#strings.append(str,suffix)}                      // also array*, list* and set*
    
    /*
     * Change case
     * Also works with arrays, lists or sets
     */
    ${#strings.toUpperCase(name)}                       // also array*, list* and set*
    ${#strings.toLowerCase(name)}                       // also array*, list* and set*
    
    /*
     * Split and join
     */
    ${#strings.arrayJoin(namesArray,',')}
    ${#strings.listJoin(namesList,',')}
    ${#strings.setJoin(namesSet,',')}
    ${#strings.arraySplit(namesStr,',')}                // returns String[]
    ${#strings.listSplit(namesStr,',')}                 // returns List<String>
    ${#strings.setSplit(namesStr,',')}                  // returns Set<String>
    
    /*
     * Trim
     * Also works with arrays, lists or sets
     */
    ${#strings.trim(str)}                               // also array*, list* and set*
    
    /*
     * Compute length
     * Also works with arrays, lists or sets
     */
    ${#strings.length(str)}                             // also array*, list* and set*
    
    /*
     * Abbreviate text making it have a maximum size of n. If text is bigger, it
     * will be clipped and finished in "..."
     * Also works with arrays, lists or sets
     */
    ${#strings.abbreviate(str,10)}                      // also array*, list* and set*
    
    /*
     * Convert the first character to upper-case (and vice-versa)
     */
    ${#strings.capitalize(str)}                         // also array*, list* and set*
    ${#strings.unCapitalize(str)}                       // also array*, list* and set*
    
    /*
     * Convert the first character of every word to upper-case
     */
    ${#strings.capitalizeWords(str)}                    // also array*, list* and set*
    ${#strings.capitalizeWords(str,delimiters)}         // also array*, list* and set*
    
    /*
     * Escape the string
     */
    ${#strings.escapeXml(str)}                          // also array*, list* and set*
    ${#strings.escapeJava(str)}                         // also array*, list* and set*
    ${#strings.escapeJavaScript(str)}                   // also array*, list* and set*
    ${#strings.unescapeJava(str)}                       // also array*, list* and set*
    ${#strings.unescapeJavaScript(str)}                 // also array*, list* and set*
    
    /*
     * Null-safe comparison and concatenation
     */
    ${#strings.equals(str)}
    ${#strings.equalsIgnoreCase(str)}
    ${#strings.concat(str)}
    ${#strings.concatReplaceNulls(str)}
    
    /*
     * Random
     */
    ${#strings.randomAlphanumeric(count)}
    Objects
    
    #objects : utility methods for objects in general
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Objects
     * ======================================================================
     */
    
    /*
     * Return obj if it is not null, and default otherwise
     * Also works with arrays, lists or sets
     */
    ${#objects.nullSafe(obj,default)}
    ${#objects.arrayNullSafe(objArray,default)}
    ${#objects.listNullSafe(objList,default)}
    ${#objects.setNullSafe(objSet,default)}
    Booleans
    
    #bools : utility methods for boolean evaluation
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Bools
     * ======================================================================
     */
    
    /*
     * Evaluate a condition in the same way that it would be evaluated in a th:if tag
     * (see conditional evaluation chapter afterwards).
     * Also works with arrays, lists or sets
     */
    ${#bools.isTrue(obj)}
    ${#bools.arrayIsTrue(objArray)}
    ${#bools.listIsTrue(objList)}
    ${#bools.setIsTrue(objSet)}
    
    /*
     * Evaluate with negation
     * Also works with arrays, lists or sets
     */
    ${#bools.isFalse(cond)}
    ${#bools.arrayIsFalse(condArray)}
    ${#bools.listIsFalse(condList)}
    ${#bools.setIsFalse(condSet)}
    
    /*
     * Evaluate and apply AND operator
     * Receive an array, a list or a set as parameter
     */
    ${#bools.arrayAnd(condArray)}
    ${#bools.listAnd(condList)}
    ${#bools.setAnd(condSet)}
    
    /*
     * Evaluate and apply OR operator
     * Receive an array, a list or a set as parameter
     */
    ${#bools.arrayOr(condArray)}
    ${#bools.listOr(condList)}
    ${#bools.setOr(condSet)}
    Arrays
    
    #arrays : utility methods for arrays
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Arrays
     * ======================================================================
     */
    
    /*
     * Converts to array, trying to infer array component class.
     * Note that if resulting array is empty, or if the elements
     * of the target object are not all of the same class,
     * this method will return Object[].
     */
    ${#arrays.toArray(object)}
    
    /*
     * Convert to arrays of the specified component class.
     */
    ${#arrays.toStringArray(object)}
    ${#arrays.toIntegerArray(object)}
    ${#arrays.toLongArray(object)}
    ${#arrays.toDoubleArray(object)}
    ${#arrays.toFloatArray(object)}
    ${#arrays.toBooleanArray(object)}
    
    /*
     * Compute length
     */
    ${#arrays.length(array)}
    
    /*
     * Check whether array is empty
     */
    ${#arrays.isEmpty(array)}
    
    /*
     * Check if element or elements are contained in array
     */
    ${#arrays.contains(array, element)}
    ${#arrays.containsAll(array, elements)}
    Lists
    
    #lists : utility methods for lists
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Lists
     * ======================================================================
     */
    
    /*
     * Converts to list
     */
    ${#lists.toList(object)}
    
    /*
     * Compute size
     */
    ${#lists.size(list)}
    
    /*
     * Check whether list is empty
     */
    ${#lists.isEmpty(list)}
    
    /*
     * Check if element or elements are contained in list
     */
    ${#lists.contains(list, element)}
    ${#lists.containsAll(list, elements)}
    
    /*
     * Sort a copy of the given list. The members of the list must implement
     * comparable or you must define a comparator.
     */
    ${#lists.sort(list)}
    ${#lists.sort(list, comparator)}
    Sets
    
    #sets : utility methods for sets
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Sets
     * ======================================================================
     */
    
    /*
     * Converts to set
     */
    ${#sets.toSet(object)}
    
    /*
     * Compute size
     */
    ${#sets.size(set)}
    
    /*
     * Check whether set is empty
     */
    ${#sets.isEmpty(set)}
    
    /*
     * Check if element or elements are contained in set
     */
    ${#sets.contains(set, element)}
    ${#sets.containsAll(set, elements)}
    Maps
    
    #maps : utility methods for maps
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Maps
     * ======================================================================
     */
    
    /*
     * Compute size
     */
    ${#maps.size(map)}
    
    /*
     * Check whether map is empty
     */
    ${#maps.isEmpty(map)}
    
    /*
     * Check if key/s or value/s are contained in maps
     */
    ${#maps.containsKey(map, key)}
    ${#maps.containsAllKeys(map, keys)}
    ${#maps.containsValue(map, value)}
    ${#maps.containsAllValues(map, value)}
    Aggregates
    
    #aggregates : utility methods for creating aggregates on arrays or collections
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Aggregates
     * ======================================================================
     */
    
    /*
     * Compute sum. Returns null if array or collection is empty
     */
    ${#aggregates.sum(array)}
    ${#aggregates.sum(collection)}
    
    /*
     * Compute average. Returns null if array or collection is empty
     */
    ${#aggregates.avg(array)}
    ${#aggregates.avg(collection)}
    Messages
    
    #messages : utility methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{...} syntax.
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Messages
     * ======================================================================
     */
    
    /*
     * Obtain externalized messages. Can receive a single key, a key plus arguments,
     * or an array/list/set of keys (in which case it will return an array/list/set of 
     * externalized messages).
     * If a message is not found, a default message (like '??msgKey??') is returned.
     */
    ${#messages.msg('msgKey')}
    ${#messages.msg('msgKey', param1)}
    ${#messages.msg('msgKey', param1, param2)}
    ${#messages.msg('msgKey', param1, param2, param3)}
    ${#messages.msgWithParams('msgKey', new Object[] {param1, param2, param3, param4})}
    ${#messages.arrayMsg(messageKeyArray)}
    ${#messages.listMsg(messageKeyList)}
    ${#messages.setMsg(messageKeySet)}
    
    /*
     * Obtain externalized messages or null. Null is returned instead of a default
     * message if a message for the specified key is not found.
     */
    ${#messages.msgOrNull('msgKey')}
    ${#messages.msgOrNull('msgKey', param1)}
    ${#messages.msgOrNull('msgKey', param1, param2)}
    ${#messages.msgOrNull('msgKey', param1, param2, param3)}
    ${#messages.msgOrNullWithParams('msgKey', new Object[] {param1, param2, param3, param4})}
    ${#messages.arrayMsgOrNull(messageKeyArray)}
    ${#messages.listMsgOrNull(messageKeyList)}
    ${#messages.setMsgOrNull(messageKeySet)}
    IDs
    
    #ids : utility methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).
    /*
     * ======================================================================
     * See javadoc API for class org.thymeleaf.expression.Ids
     * ======================================================================
     */
    
    /*
     * Normally used in th:id attributes, for appending a counter to the id attribute value
     * so that it remains unique even when involved in an iteration process.
     */
    ${#ids.seq('someId')}
    
    /*
     * Normally used in th:for attributes in <label> tags, so that these labels can refer to Ids
     * generated by means if the #ids.seq(...) function.
     *
     * Depending on whether the <label> goes before or after the element with the #ids.seq(...)
     * function, the "next" (label goes before "seq") or the "prev" function (label goes after 
     * "seq") function should be called.
     */
    ${#ids.next('someId')}
    ${#ids.prev('someId')}

七.thymeleaf的$和\*的区别:

<div th:object="${session.user}">
        <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
        <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p>
        <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
     </div>

这等同于如下方式：

<div>
      <p>Name: <span th:text="${session.user.firstName}">Sebastian</span>.</p>
      <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
      <p>Nationality: <span th:text="${session.user.nationality}">Saturn</span>.</p>
    </div>

也可以混用,如下:

<div th:object="${session.user}">
      <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
      <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
      <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
    </div>

当一个对象的选择,选择的对象将也可用美元作为\#对象表达变量表达式：

<div th:object="${session.user}">
      <p>Name: <span th:text="${#object.firstName}">Sebastian</span>.</p>
      <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
      <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
    </div>

如果没有执行对象选择,美元和星号语法是完全等价的:

<div>
      <p>Name: <span th:text="*{session.user.name}">Sebastian</span>.</p>
      <p>Surname: <span th:text="*{session.user.surname}">Pepper</span>.</p>
      <p>Nationality: <span th:text="*{session.user.nationality}">Saturn</span>.</p>
    </div>

### thymeleaf的Url属性 ###

一.使用表达式形式:@\{...\}

例如：

带参数的URL连接：

@{/order/process(execId=${execId},execType='FAST')}

相当于:/order/process?execId=$\{execId\},execType='FAST'

拼接URL写法:

href和th:href的区别：

当两者同时出现时，最终实现的效果是th:href的效果

**@\{...\}链接网址表达式**

一般和 th:href、th:src进行结合使用，用于显示Web 应用中的URL链接。通过@\{...\}表达式Thymeleaf 可以帮助我们拼接上web应用访问的全路径，同时我们可以通过（）进行参数的拼接

**代码演示：**

模版代码：

结果页面：

--------------------

模版代码：

结果页面：

--------------------

模版代码：

结果页面：

## Literals即为文字 ##

**一.Text literals:文本文字**

文本文字只是字符串指定的单引号之间。他们可以包含任何字符,但你应避免任何单引号里面\\ '

<p>
      Now you are looking at a <span th:text="'working web application'">template file</span>.
    </p>

如果是带空格什么的不连贯的一段话，例如working web application，必须要用单引号引起来才能被解析，如果是如下则不能被解析，会出现错误:

<p>
      Now you are looking at a <span th:text="working web application">template file</span>.
    </p>

如果是连贯的不分开的如下是正确被解析的:

<p>
      Now you are looking at a <span th:text="workingwebapplication">template file</span>.
    </p>

**二:文字数量**

数字文字看起来像:数字。

例子:

<p>The year is <span th:text="2014">1492</span>.</p>
    <p>In two years, it will be <span th:text="2013 + 2">1494</span>.</p>

显示结果:

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> </td> 
   <td> <p><code>The year is 2014</code></p> <p><code>In two years, it will be 2016</code></p> </td> 
  </tr> 
 </tbody> 
</table>

**三.布尔型常量**

布尔常量true和false。例如:

<div th:if="${user.isAdmin()} == false"> 如果是false我显示</div>

注意,在上面的例子中,==false写在括号外,因此Thymeleaf本身照顾它。如果它是写在括号内,这将是OGNL/SpringEL引擎展示出:

<div th:if="${user.isAdmin() == false}"> 如果是false我显示</div>

**四.空的文字**

<div th:if="${variable.something} == null">如果为空我显示</div>

**五.附加的文本**

文本,无论他们是文字或评估的结果变量或消息表达式,可以很容易地添加使用+运算符:

th:text="'The name of the user is ' + ${user.name}"

**六.文字替换:**

文字替换允许简单的格式化字符串包含值的变量而不需要附加的文字……‘+’……”。这些替换必须包围竖线(|),如:

等同于：

文字替换可以结合其他类型的表达式:

算术运算：

### thymeleaf比较器问题 ###

thymeleaf比较器与平等：

值表达可以是>、<、> =、< =符号,像往常一样,也是= =和!=操作符可以用来检查平等，但是>、<、> =、< =不能用，要用`gt` (`>`), `lt` (`<`), `ge` (`>=`), `le` (`<=`), `not` (`!`). Also `eq` (`==`), `neq`/`ne` (`!=`)。注意,XML建立< 和 >符号不应使用属性值,所以他们应该取代& lt;调整;

th:if="${prodStat.count} > 1"

在thymeleaf中出现< ,>符号不能被当做大于小于解析，要用`gt` (`>`), `lt` (`<`)代替；

### **thymeleaf条件表达式** ###

条件表达式形式:**`condition`, `then` and `else`**

混合使用表达式实例:

其他表达式也可以省略,在这种情况下,返回一个null值如果条件是错误的

### **thymeleaf中th:eath迭代集合** ###

**一.th:eath迭代集合用法:**

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

**二.迭代下标变量用法：**

状态变量定义在一个th:每个属性和包含以下数据:

1.当前迭代索引,从0开始。这是索引属性。index

2.当前迭代索引,从1开始。这是统计属性。count

3.元素的总量迭代变量。这是大小属性。　size

4.iter变量为每个迭代。这是目前的财产。　current

5.是否当前迭代是奇数还是偶数。这些even/odd的布尔属性。

6.是否第一个当前迭代。这是first布尔属性。

7.是否最后一个当前迭代。这是last布尔属性。

用法实例：

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

打印出status的值为:

![7733142d140f78fa4fdea598e479609d.png][]

如果你不显式地设置迭代变量,Thymeleaf总是会为您创建一个统计的名字作为后缀iter变量:

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

<table>
      <tr>
        <th>NAME</th>
        <th>PRICE</th>
        <th>IN STOCK</th>
      </tr>
      <tr th:each="prod : ${prods}" th:class="${prodStat.odd}? 'odd'">
        <td th:text="${prod.name}">Onions</td>
        <td th:text="${prod.price}">2.41</td>
        <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
      </tr>
    </table>

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

### **thymeleaf中条件判断** ###

**一.简单的条件:“if”和“unless”**

th:if用法实例：

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

如果值不是空:

1.如果一个布尔值,是true。

2.如果值是一个数字,非零 non-zero

3.如果是一个字符,非零值　non-zero

4.如果值是一个字符串,而不是“false”,“off” or “no”

5.如果值不是布尔,一个数字,一个字符或字符串。

(如果值是null,th:if将评估为false)。

th:unless用法：

二.switch用法：(`th:switch` / `th:case)`

<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>

被指定为默认选项用th:case="\*"；相当于default,例如:

<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 is some other thing</p>
    </div>

### **Thymeleaf中模板使用** ###

**一.包括模板片段:**

**　　**1：定义和引用片段，我们经常会想要包含在模板片段来自其他模板。常见的用途是页脚、标题、菜单…;

为了做到这一点,Thymeleaf需要我们定义包含可用的片段,我们可以通过使用th:fragment属性。

定义一个页面底部footer页面，在每一个需要的页面都可以用的模板，可以通过使用th:fragment属性

上面的代码定义了一个叫做副本的片段,我们可以很容易地包含在我们的主页上通过使用`th:include` or `th:replace属性`之一:

引用片段没有th:fragment:

页面引用：th:include="templatename::domselector"

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>templatename是要引入页面的路劲加上去掉后缀的名称，例如footer.html页面建立在/WEB-INF/templates/footer.html，所以templatename为footer;domselector就是dom选择器，即为th:fragment中的值，或是选择id</code></p> </td> 
  </tr> 
 </tbody> 
</table>

<body>
      ...
      <div th:include="footer :: #copy-section"></div>
      
    </body

注意:

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> <p>4</p> <p>5</p> <p>6</p> <p>7</p> <p>8</p> <p>9</p> <p>10</p> </td> 
   <td> <p><code>带有公共的页面，不要带有</code></p> <p><code>&lt;</code><code>html</code><code>&gt;</code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;</code><code>head</code><code>&gt;&lt;/</code><code>head</code><code>&gt;</code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;</code><code>body</code><code>&gt;&lt;/</code><code>body</code><code>&gt;</code></p> <p><code>&lt;/</code><code>html</code><code>&gt;</code></p> <p><code>直接写内容：</code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;</code><code>div</code>&nbsp;<code>th:fragment="copy"&gt;</code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>© 2011 The Good Thymes Virtual Grocery</code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;/</code><code>div</code><code>&gt;</code></p> <p><code>&nbsp;</code>&nbsp;</p> </td> 
  </tr> 
 </tbody> 
</table>

扩展写法，希望能灵活运用：

**二.可参数化的片段签名**

**　可以像参数一样传入参数:**

两种调用方式引入页面:

如果没有带参数,如下形式:

依然可以使用带参数的引入，但是必须使用第二种引入方式,另一种不行:如下是正确的引入方式

这样事实上,这将是相当于一个`th:include`和`th:with的`组合

# [thymeleaf中的th:assert用法][thymeleaf_th_assert] #

### th:assert 断言标签 ###

th:assert属性可以指定一个以逗号分隔的表达式对其进行评估并生产适用于每一个评价,如果不抛出异常

这方便验证参数的一个片断签名

这样只有传入值才能引入成功，否则不会被引入。

# [thymeleaf中的th:remove用法][thymeleaf_th_remove] #

**一.删除模板片段使用th:remove属性**

th:remove的值如下:

1.all:删除包含标签和所有的孩子。

2.body:不包含标记删除,但删除其所有的孩子。

3.tag:包含标记的删除,但不删除它的孩子。

4.all-but-first:删除所有包含标签的孩子,除了第一个。

5.none:什么也不做。这个值是有用的动态评估。

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

<table>
      <tr>
        <th>NAME</th>
        <th>PRICE</th>
        <th>IN STOCK</th>
        <th>COMMENTS</th>
      </tr>
      <tr th:each="prod : ${prods}" th:class="${prodStat.odd}? 'odd'">
        <td th:text="${prod.name}">Onions</td>
        <td th:text="${prod.price}">2.41</td>
        <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
        <td>
          <span th:text="${#lists.size(prod.comments)}">2</span> comment/s
          <a href="comments.html" 
             th:href="@{/product/comments(prodId=${prod.id})}" 
             th:unless="${#lists.isEmpty(prod.comments)}">view</a>
        </td>
      </tr>
      <tr class="odd" th:remove="all">
        <td>Blue Lettuce</td>
        <td>9.55</td>
        <td>no</td>
        <td>
          <span>0</span> comment/s
        </td>
      </tr>
      <tr th:remove="all">
        <td>Mild Cinnamon</td>
        <td>1.99</td>
        <td>yes</td>
        <td>
          <span>3</span> comment/s
          <a href="comments.html">view</a>
        </td>
      </tr>
    </table>

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

结果为:

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

<table>
      <tr>
        <th>NAME</th>
        <th>PRICE</th>
        <th>IN STOCK</th>
        <th>COMMENTS</th>
      </tr>
      <tr>
        <td>Fresh Sweet Basil</td>
        <td>4.99</td>
        <td>yes</td>
        <td>
          <span>0</span> comment/s
        </td>
      </tr>
      <tr class="odd">
        <td>Italian Tomato</td>
        <td>1.25</td>
        <td>no</td>
        <td>
          <span>2</span> comment/s
          <a href="/gtvg/product/comments?prodId=2">view</a>
        </td>
      </tr>
      <tr>
        <td>Yellow Bell Pepper</td>
        <td>2.50</td>
        <td>yes</td>
        <td>
          <span>0</span> comment/s
        </td>
      </tr>
      <tr class="odd">
        <td>Old Cheddar</td>
        <td>18.75</td>
        <td>yes</td>
        <td>
          <span>1</span> comment/s
          <a href="/gtvg/product/comments?prodId=4">view</a>
        </td>
      </tr>
    </table>

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

最后两行<tr>被删除了。

二.th:remove属性可以采取任何Thymeleaf标准表达式,只要允许它返回一个字符串值(`all`, `tag`, `body`, `all-but-first` or `none`)。

这意味着删除可能是有条件的:

<a href="/something" th:remove="${condition}? tag : none">Link text not to be removed</a>

`th:remove` 把`null` 等同于 `none，所以下面和上面的其实是一样的：`

<a href="/something" th:remove="${condition}? tag">Link text not to be removed</a>

因此，如果`${condition}` is 是false,将返回null,因此没有删除会被执行。

[参考1][1]

[参考2][2]

[thymeleaf]: http://www.thymeleaf.org/doc/usingthymeleaf.html
[48304ba5e6f9fe08f3fa1abda7d326ab.png]: /images/20221123/ceb5940b8e5644da8558693338029c80.png
[7733142d140f78fa4fdea598e479609d.png]: /images/20221123/7e6b420bb69e4bf181fe32a3d4b89abd.png
[thymeleaf_th_assert]: https://www.cnblogs.com/suncj/p/4030934.html
[thymeleaf_th_remove]: https://www.cnblogs.com/suncj/p/4030975.html
[1]: https://www.debug8.com/java/t_18124.html
[2]: https://www.cnblogs.com/suncj/p/4028768.html