在JSP EL中使用接口默认方法时，“类型上找不到属性”

您可以通过创建

ELResolver

SimpleSpringBeanELResolver

ELResolver

此类查找在bean的接口上定义的bean属性签名，并尝试使用它们。如果在接口上未找到bean prop签名，它将继续按照默认行为链发送它。

import org.apache.commons.beanutils.PropertyUtils;import org.springframework.beans.factory.BeanFactory;import org.springframework.beans.factory.access.el.SimpleSpringBeanELResolver;import javax.el.ELContext;import javax.el.ELException;import java.beans.PropertyDescriptor;import java.lang.reflect.InvocationTargetException;import java.util.Optional;import java.util.stream.Stream;public class DefaultMethodELResolver extends SimpleSpringBeanELResolver {        public DefaultMethodELResolver(BeanFactory beanFactory) {        super(beanFactory);    }    @Override    public Object getValue(ELContext elContext, Object base, Object property) throws ELException {        if(base != null && property != null) { String propStr = property.toString(); if(propStr != null) {     Optional<Object> ret = attemptDefaultMethodInvoke(base, propStr);     if (ret != null) {         // notify the ELContext that our prop was resolved and return it.         elContext.setPropertyResolved(true);         return ret.get();     } }        }        // delegate to super        return super.getValue(elContext, base, property);    }        private Optional<Object> attemptDefaultMethodInvoke(Object base, String property) {        try { // look through interfaces and try to find the method for(Class<?> intf : base.getClass().getInterfaces()) {     // find property descriptor for interface which matches our property     Optional<PropertyDescriptor> desc = Stream.of(PropertyUtils.getPropertyDescriptors(intf))  .filter(d->d.getName().equals(property))  .findFirst();     // onLY handle default methods, if its not default we dont handle it     if(desc.isPresent() && desc.get().getReadMethod() != null && desc.get().getReadMethod().isDefault()) {         // found read method, invoke it on our object.         return Optional.ofNullable(desc.get().getReadMethod().invoke(base));     } }        } catch (InvocationTargetException | IllegalAccessException e) { throw new RuntimeException("Unable to access default method using reflection", e);        }        // no value found, return null        return null;    }}

然后，您需要

ELResolver

@Configuration...public class SpringConfig extends WebMvcConfigurationSupport {    ...    @Override    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {        ...        // add our default method resolver to our ELResolver list.        JspApplicationContext jspContext = JspFactory.getDefaultFactory().getJspApplicationContext(getServletContext());        jspContext.addELResolver(new DefaultMethodELResolver(getApplicationContext()));    }}

我不能100％地确定这是否是添加我们的解析器的适当位置，但是它确实可以正常工作。您也可以在以下期间加载ELResolver

javax.servlet.ServletContextListener.contextInitialized

这是

ELResolver