Thymeleaf 关于自定义转换的文档 Configuring a Conversion Service 中，是通过WebMvcConfigurerAdapter 来配置的，但是目前最新版的Spring Boot(V3.2.5)，已经没有这个类了，得用 WebMvcConfigurationSupport 配置，比如实现一个自定义的 Formatter
FloatArrayFormatter.java
package com.example.demo;import java.text.ParseException;
import java.util.Locale;import org.springframework.format.Formatter;public class FloatArrayFormatter implements Formatter<float[]> {@Overridepublic String print(float[] object, Locale locale) {StringBuilder sb = new StringBuilder();for (int i = 0; i < object.length; i++) {sb.append(String.valueOf(object[i]));if(i < object.length - 1) {sb.append(", ");}}return sb.toString();}@Overridepublic float[] parse(String text, Locale locale) throws ParseException {return null;}}
然后创建一个配置类（实现addResourceHandlers是为了让资源可用，本人测试的时候就出现了static目录下的bootstrap加载不了）：
package com.example.demo;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;@Configuration
public class WebConfig extends WebMvcConfigurationSupport {@Overridepublic void addResourceHandlers(ResourceHandlerRegistry registry) {registry.addResourceHandler("/**").addResourceLocations("classpath:/static/").addResourceLocations("classpath:/META-INF/resources/").addResourceLocations("classpath:/public/").addResourceLocations("classpath:/resources/");super.addResourceHandlers(registry);}@Overrideprotected void addFormatters(FormatterRegistry registry) {super.addFormatters(registry);registry.addFormatter(floatArrayFormatter());}@Beanpublic FloatArrayFormatter floatArrayFormatter() {return new FloatArrayFormatter();}
}
创建一个页面
HomeController.java
package com.example.demo;import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;@Controller
public class HomeController {@ModelAttributepublic void setModel(Model model) {model.addAttribute("arr", new float[]{ 3.141592f, 5.2f });}@GetMapping("/")public String home() {return "home";}}
html页面中使用两层大括号 ${{arr}} 来调用自定义的Formatter显示 float 数组
home.html
<!DOCTYPE html>
<html xmlns = "http://www.w3.org/1999/xhtml"xmlns:th = "http://www.thymeleaf.org"><head><link href="/bootstrap-5.3.3-dist/css/bootstrap.min.css" rel="stylesheet"><script src="/bootstrap-5.3.3-dist/js/bootstrap.bundle.min.js"></script></head><body><div class="input-group"><textarea style="white-space: pre-wrap;" class="form-control" th:text="${{arr}}"></textarea></div></body>
</html>
