如何将自定义版本的WebDataBinder注入Spring 3 MVC？

  • Z时代
  • 2024-01-10
  • 分类：问答

我编写了WebDataBinder的自定义实现。将来，我想对其进行增强，以便它在类本身上查找注释，并弄清楚是否应将数据绑定到它。

如何将此类代替WebDataBinder注入到Spring上下文中？

我想要的是，如果运行此代码，则将注入我的WebDataBinder版本，而不是默认的Spring版本。

@Controller
public class MyFormController {
    @InitBinder
    public void initBinder(WebDataBinder binder) {
        // ...
    }
    // ...
}

我对WebDataBinder的自定义实现。它使我可以按类而不是按方法名称来排除数据绑定。

    package com.companyname.spring;
    import org.springframework.beans.MutablePropertyValues;
    import org.springframework.util.StringUtils;
    import org.springframework.web.bind.WebDataBinder;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    public class CustomDataBinder extends WebDataBinder {
        List<Class> disallowedClasses = new ArrayList<>();
        public CustomDataBinder(Object target) {
            super(target);
        }
        public CustomDataBinder(Object target, String objectName) {
            super(target, objectName);
        }
        public CustomDataBinder disallowClass(Class... classes) {
            Collections.addAll(disallowedClasses, classes);
            return this;
        }
        @Override
        protected void doBind(MutablePropertyValues mpvs) {
            if(disallowedClasses.contains(getTarget().getClass())) {
                if (logger.isDebugEnabled()) {
                    logger.debug("DataBinder will not bind class [" + getTarget().getClass().getSimpleName() + "] because it appears in the list of disallowed classes [" + StringUtils.collectionToCommaDelimitedString(disallowedClasses) + "]");
                }
            } else {
                super.doBind(mpvs);
            }
        }
    }

编辑1

回答：

@Configuration
@ComponentScan(basePackageClasses = RootContextConfig.class)
@EnableTransactionManagement
@EnableWebSecurity
@EnableAsync
@EnableSpringConfigured
@EnableLoadTimeWeaving
public class RootContextConfig extends WebMvcConfigurationSupport {
    @Bean
    public RequestMappingHandlerAdapter requestMappingHandlerAdapter() {
        List<HandlerMethodArgumentResolver> argumentResolvers = new ArrayList<HandlerMethodArgumentResolver>();
        addArgumentResolvers(argumentResolvers);
        List<HandlerMethodReturnValueHandler> returnValueHandlers = new ArrayList<HandlerMethodReturnValueHandler>();
        addReturnValueHandlers(returnValueHandlers);
        RequestMappingHandlerAdapter adapter = new CustomRequestMappingHandlerAdapter();
        adapter.setContentNegotiationManager(mvcContentNegotiationManager());
        adapter.setMessageConverters(getMessageConverters());
        adapter.setWebBindingInitializer(getConfigurableWebBindingInitializer());
        adapter.setCustomArgumentResolvers(argumentResolvers);
        adapter.setCustomReturnValueHandlers(returnValueHandlers);
        AsyncSupportConfigurer configurer = new AsyncSupportConfigurer();
        configureAsyncSupport(configurer);
//All the methods called off of configurer are giving me errors because they have protected level access. I'm not really sure how they're being called in the code I copied this from.
        if (configurer.getTaskExecutor() != null) {
            adapter.setTaskExecutor(configurer.getTaskExecutor());
        }
        if (configurer.getTimeout() != null) {
            adapter.setAsyncRequestTimeout(configurer.getTimeout());
        }
        adapter.setCallableInterceptors(configurer.getCallableInterceptors());
        adapter.setDeferredResultInterceptors(configurer.getDeferredResultInterceptors());
        return adapter;
    }

自定义RequestMappingHandlerAdapter

package com.companyname.dirtylibs.spring;
import org.springframework.web.method.annotation.InitBinderDataBinderFactory;
import org.springframework.web.method.support.InvocableHandlerMethod;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
import org.springframework.web.servlet.mvc.method.annotation.ServletRequestDataBinderFactory;
import java.util.List;
public class CustomRequestMappingHandlerAdapter extends RequestMappingHandlerAdapter {
    @Override
    protected InitBinderDataBinderFactory createDataBinderFactory(List<InvocableHandlerMethod> binderMethods) throws Exception {
        return new CustomInitBinderDataBinderFactory(binderMethods, getWebBindingInitializer());
    }
}

自定义InitBinderDataBinderFactory

package com.companyname.dirtylibs.spring;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.support.WebBindingInitializer;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.bind.support.WebRequestDataBinder;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.annotation.InitBinderDataBinderFactory;
import org.springframework.web.method.support.InvocableHandlerMethod;
import org.springframework.web.servlet.mvc.method.annotation.ServletRequestDataBinderFactory;
import java.util.List;
public class CustomInitBinderDataBinderFactory extends InitBinderDataBinderFactory {
    /**
     * Create a new instance.
     *
     * @param binderMethods {@code @InitBinder} methods, or {@code null}
     * @param initializer   for global data binder intialization
     */
    public CustomInitBinderDataBinderFactory(List<InvocableHandlerMethod> binderMethods, WebBindingInitializer initializer) {
        super(binderMethods, initializer);
    }
    @Override
    protected CustomDataBinder createBinderInstance(Object target, String objectName, NativeWebRequest webRequest) throws Exception {
        return new CustomDataBinder(target, objectName);
    }
}

回答：

这不是一个简单的任务。Spring允许进行大量的自定义，但是，该死，这种更改并不有趣。

您需要扩展RequestMappingHandlerAdapter该类并重写以下方法

/**
 * Template method to create a new InitBinderDataBinderFactory instance.
 * <p>The default implementation creates a ServletRequestDataBinderFactory.
 * This can be overridden for custom ServletRequestDataBinder subclasses.
 * @param binderMethods {@code @InitBinder} methods
 * @return the InitBinderDataBinderFactory instance to use
 * @throws Exception in case of invalid state or arguments
 */
protected InitBinderDataBinderFactory createDataBinderFactory(List<InvocableHandlerMethod> binderMethods)
        throws Exception {
    return new ServletRequestDataBinderFactory(binderMethods, getWebBindingInitializer());
}

除了返回ServletRequestDataBinderFactory，您需要返回一个InitBinderDataBinderFactory返回自定义WebDataBinder实例的自定义。

此更改意味着您不能使用默认设置@EnableWebMvc或<mvc:annotation-

driven/>配置。那是因为它们RequestMappingHandlerAdapter默认使用，但是您需要注册自己的类。

但是，您可以覆盖带@Bean注释的WebMvcConfigurationSupport#requestMappingHandlerAdapter()方法，并提供自己的实现以返回自己的类型。查看该实现对提示的作用。

以上是 如何将自定义版本的WebDataBinder注入Spring 3 MVC？ 的全部内容， 来源链接： utcz.com/qa/416502.html

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