SpringBoot 手动渲染Thymeleaf模版工具类

        为了解决在模版中通过 @bean.method() 方式调用 spring 的bean对象方法报错问题,参考ThymeleafView的rendFragment()方法, 删减了一些用不到的代码,记录一下备用.

import org.springframework.context.ApplicationContext;
import org.springframework.core.convert.ConversionService;
import org.springframework.web.servlet.support.RequestContext;
import org.thymeleaf.IEngineConfiguration;
import org.thymeleaf.context.WebExpressionContext;
import org.thymeleaf.spring5.ISpringTemplateEngine;
import org.thymeleaf.spring5.context.webmvc.SpringWebMvcThymeleafRequestContext;
import org.thymeleaf.spring5.expression.ThymeleafEvaluationContext;
import org.thymeleaf.util.FastStringWriter;
 
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.Writer;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
 
/**
 * 结合springMVC使用的thymeleaf 模版手动渲染,解决模版页面 @xxx 调用springbean方法报错问题
 */
public class ThymeleafUtil {
 
    public static String renderTemplate(String templateName, Map modelMap,
                                 HttpServletRequest request, HttpServletResponse response,
                                 ApplicationContext applicationContext,
                                 ISpringTemplateEngine viewTemplateEngine) throws Exception {
        ServletContext servletContext = request.getServletContext();
 
        Map mergedModel = new HashMap(30);
 
        if (modelMap != null) {
            mergedModel.putAll(modelMap);
        }
 
        RequestContext requestContext = new RequestContext(request, response, servletContext, mergedModel);
        SpringWebMvcThymeleafRequestContext thymeleafRequestContext = new SpringWebMvcThymeleafRequestContext(requestContext, request);
        if (!mergedModel.containsKey("springRequestContext")) {
            mergedModel.put("springRequestContext", requestContext);
        }
        if (!mergedModel.containsKey("springMacroRequestContext")) {
            mergedModel.put("springMacroRequestContext", requestContext);
        }
 
        mergedModel.put("thymeleafRequestContext", thymeleafRequestContext);
        ConversionService conversionService = (ConversionService) request.getAttribute(ConversionService.class.getName());
        ThymeleafEvaluationContext evaluationContext = new ThymeleafEvaluationContext(applicationContext, conversionService);
        mergedModel.put("thymeleaf::EvaluationContext", evaluationContext);
        IEngineConfiguration configuration = viewTemplateEngine.getConfiguration();
        WebExpressionContext context = new WebExpressionContext(configuration, request, response, servletContext, Locale.getDefault(), mergedModel);
 
        Writer templateWriter = new FastStringWriter(1024);
        viewTemplateEngine.process(templateName, null, context, (Writer) templateWriter);
        return templateWriter.toString();
 
    }
}