Thymeleaf 提示： Cannot perform conversion to XML from legacy HTML:

素颜马尾好姑娘i 2023-10-10 11:24 26阅读 0赞

SpringBoot 1.5.x 集成Thymeleaf 2.1.x 提示如下错误信息：

[http-nio-9096-exec-1] ERROR org.thymeleaf.TemplateEngine - [THYMELEAF][http-nio-9096-exec-1] Exception processing template "index": Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode [http://nekohtml.sourceforge.net]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.
    2020-08-04 14:09:28.580 [http-nio-9096-exec-1] ERROR org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.thymeleaf.exceptions.ConfigurationException: Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode [http://nekohtml.sourceforge.net]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.] with root cause
    org.thymeleaf.exceptions.ConfigurationException: Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode [http://nekohtml.sourceforge.net]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.

产生改错误的原因是：thymeleaf 设置HTML5版本：

# 设置HTML 模板
    spring.thymeleaf.mode=HTML5

很容易出现以下错误：

org.xml.sax.SAXParseException: 元素类型 "input" 必须由匹配的结束标记 "</input>" 终止。

为了兼容HTML4 和HTML5 ，修改为HTML 的兼容版本:

# 设置HTML兼容版本
    spring.thymeleaf.mode=LEGACYHTML5

使用HTML兼容版本，提示SpringBoot 1.5.x 集成Thymeleaf 2.1.x 提示如下错误信息：

\[http-nio-9096-exec-1\] ERROR org.thymeleaf.TemplateEngine - \[THYMELEAF\]\[http-nio-9096-exec-1\] Exception processing template "index": Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode \[http://nekohtml.sourceforge.net\]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.

2020-08-04 14:09:28.580 \[http-nio-9096-exec-1\] ERROR org.apache.catalina.core.ContainerBase.\[Tomcat\].\[localhost\].\[/\].\[dispatcherServlet\] - Servlet.service() for servlet \[dispatcherServlet\] in context with path \[\] threw exception \[Request processing failed; nested exception is org.thymeleaf.exceptions.ConfigurationException: Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode \[http://nekohtml.sourceforge.net\]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.\] with root cause

org.thymeleaf.exceptions.ConfigurationException: Cannot perform conversion to XML from legacy HTML: The nekoHTML library is not in classpath. nekoHTML 1.9.15 or newer is required for processing templates in "LEGACYHTML5" mode \[http://nekohtml.sourceforge.net\]. Maven spec: "net.sourceforge.nekohtml::nekohtml::1.9.15". IMPORTANT: DO NOT use versions of nekoHTML older than 1.9.15.

产生改错误的原因是：thymeleaf 设置HTML5版本：

\# 设置HTML 模板

spring.thymeleaf.mode=HTML5

很容易出现以下错误：

org.xml.sax.SAXParseException: 元素类型 "input" 必须由匹配的结束标记 "</input>" 终止。

为了兼容HTML4 和HTML5 ，修改为HTML 的兼容版本:

\# 设置HTML兼容版本

spring.thymeleaf.mode=LEGACYHTML5

使用HTML兼容版本，提示最开始的错误信息，解决方案是添加nekoHTML 1.9.15 或者更新版本，pom.xml 文件如下：

<dependency>
    			<groupId>net.sourceforge.nekohtml</groupId>
    			<artifactId>nekohtml</artifactId>
    			<version>1.9.22</version>
    		</dependency>