Question

我是Spring MVC的新手，我正在尝试理解以下代码

package com.companyname.springapp.web;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.companyname.springapp.service.PriceIncrease;
import com.companyname.springapp.service.ProductManager;

@Controller
@RequestMapping(value="/priceincrease.htm")
public class PriceIncreaseFormController {

    /** Logger for this class and subclasses */
    protected final Log logger = LogFactory.getLog(getClass());

    @Autowired
    private ProductManager productManager;

    @RequestMapping(method = RequestMethod.POST)
    public String onSubmit(@Valid PriceIncrease priceIncrease, BindingResult result)
    {
        if (result.hasErrors()) {
            return "priceincrease";
        }

        int increase = priceIncrease.getPercentage();
        logger.info("Increasing prices by " + increase + "%.");

        productManager.increasePrice(increase);

        return "redirect:/hello.htm";
    }

    @RequestMapping(method = RequestMethod.GET)
    protected PriceIncrease formBackingObject(HttpServletRequest request) throws ServletException {
        PriceIncrease priceIncrease = new PriceIncrease();
        priceIncrease.setPercentage(15);
        return priceIncrease;
    }

    public void setProductManager(ProductManager productManager) {
        this.productManager = productManager;
    }

    public ProductManager getProductManager() {
        return productManager;
    }

}

据我所知，BindingResult是一个接口，而onSubmit方法接收一个BindingResult对象。我不明白的是：谁实现了这个界面来创建对象以及实现在哪里？

这是servlet xml

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd">

       <bean id="productManager" class="com.companyname.springapp.service.SimpleProductManager">
         <property name="products">
            <list>
                <ref bean="product1"/>
                <ref bean="product2"/>
                <ref bean="product3"/>
            </list>
         </property>
       </bean>

       <bean id="product1" class="com.companyname.springapp.domain.Product">
         <property name="description" value="Lamp"/>
         <property name="price" value="5.75"/>
       </bean>

       <bean id="product2" class="com.companyname.springapp.domain.Product">
         <property name="description" value="Table"/>
         <property name="price" value="75.25"/>
       </bean>

       <bean id="product3" class="com.companyname.springapp.domain.Product">
         <property name="description" value="Chair"/>
         <property name="price" value="22.79"/>
       </bean>

       <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
         <property name="basename" value="messages"/>
       </bean>

       <!-- Scans the classpath of this application for @Components to deploy as beans -->
       <context:component-scan base-package="com.companyname.springapp.web" />

       <!-- Configures the @Controller programming model -->
       <mvc:annotation-driven/>

       <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
         <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property>
         <property name="prefix" value="/WEB-INF/views/"></property>
         <property name="suffix" value=".jsp"></property>        
       </bean>
</beans>

如果这有帮助我不会，但我使用的是Tomcat 7.0，整个代码就在这里：http://docs.spring.io/docs/Spring-MVC-step-by-step/

Answer 1

谁实现了此接口来创建对象以及该实现在哪里？

在Spring框架中实现并由您的上下文实例化。在上面的例子中，BeanPropertyBindingResult.class是BindingResult实例化的精确实现 http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/validation/BeanPropertyBindingResult.html

谁实现了弹簧BindingResult？

1 个答案: