Spring中的@ModelAttribute模型属性绑定详解

attribute 'name' and its alias 'value' are present with values of [XXX] and [XXX], but only one is permitted

@ModelAttribute
public void modelAttributeWithVoidMethod(ModelMap modelMap) {
    modelMap.addAttribute("modelAttributeWithVoidMethod",
                          "@ModelAttribute注释在void返回类型的方法上.");
}

@ModelAttribute
public String modelAttributeWithStringMethod() {
    return "@ModelAttribute注释String返回类型方法，会自动将返回值添加到ModelMap中，键根据返回类型生成.";
}

@ModelAttribute("defModelAttributeName")
public String modelAttributeWithStringMethodDefName(ModelMap modelMap) {
    return "@ModelAttribute注释String类型返回值方法，会自动将返回值添加到ModelMap中，键是@ModelAttribute的name或value属性值.";
}

@ModelAttribute
@RequestMapping(
    value = "/ModelAttributeWithRequestMapping.do",
    method = RequestMethod.GET)
public String modelAttributeWithRequestMapping(ModelMap modelMap) throws Exception {
    logger.info("@ModelAttribute与@RequestMapping共同作用在一个方法.");
    return "webannotations/ModelAttribute";
}

@RequestMapping(
    value = "/ModelAttributeParameters.do",
    method = RequestMethod.GET)
public ModelAndView modelAttributeParameters(@ModelAttribute("defModelAttributeName") String modelAttr,
                                             ModelMap modelMap) throws Exception {
    logger.info("@ModelAttribute注释方法参数，从ModelMap中取值：[key=defModelAttributeName, value=" + modelAttr + "].");
    return new ModelAndView("webannotations/ModelAttribute", modelMap);
}

package com.arhorchin.securitit.webannotations;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

/**
 * @author Securitit.
 * @note 演示@ModelAttribute使用方法.
 */
@Controller
@RequestMapping("/WebAnnotations")
public class ModelAttributeController {

    /**
     * logger.
     */
    private Logger logger = LoggerFactory.getLogger(ModelAttributeController.class);

    /**
     * @ModelAttribute注释
     *  void类型返回值方法. 
     *  需要手动ModelMap中添加数据.
     */
    @ModelAttribute
    public void modelAttributeWithVoidMethod(ModelMap modelMap) {
        modelMap.addAttribute("modelAttributeWithVoidMethod",
                "@ModelAttribute注释在void返回类型的方法上.");
    }

    /**
     * @ModelAttribute注释
     *  String返回类型方法. 
     *  会自动将返回值添加到ModelMap中，键根据返回类型生成.
     */
    @ModelAttribute
    public String modelAttributeWithStringMethod() {
        return "@ModelAttribute注释String返回类型方法，会自动将返回值添加到ModelMap中，键根据返回类型生成.";
    }

    /**
     * @ModelAttribute注释
     *  String类型返回值方法. 
     *  会自动将返回值添加到ModelMap中，键是@ModelAttribute的name或value属性值.
     */
    @ModelAttribute("defModelAttributeName")
    public String modelAttributeWithStringMethodDefName() {
        return "@ModelAttribute注释String类型返回值方法，会自动将返回值添加到ModelMap中，键是@ModelAttribute的name或value属性值.";
    }

    /**
     * ModelAttribute.do.
     */
    @RequestMapping(
            value = "/ModelAttribute.do",
            method = RequestMethod.GET)
    public ModelAndView modelAttribute(ModelMap modelMap) throws Exception {
        logger.info("@ModelAttribute注解测试.");
        return new ModelAndView("webannotations/ModelAttribute", modelMap);
    }
    
    /**
     * ModelAttribute.do.
     * @ModelAttribute与@RequestMapping共同注释同一方法测试.
     */
    @ModelAttribute
    @RequestMapping(
            value = "/ModelAttributeWithRequestMapping.do",
            method = RequestMethod.GET)
    public String modelAttributeWithRequestMapping() throws Exception {
        logger.info("@ModelAttribute与@RequestMapping共同作用在一个方法.");
        return "webannotations/ModelAttribute";
    }
    

    /**
     * ModelAttributeParameters.do.
     * @ModelAttribute注释参数，可以从ModelMap中取指定参数值.
     */
    @RequestMapping(
            value = "/ModelAttributeParameters.do",
            method = RequestMethod.GET)
    public ModelAndView modelAttributeParameters(@ModelAttribute("defModelAttributeName") String modelAttr,
            ModelMap modelMap) throws Exception {
        logger.info("@ModelAttribute注释方法参数，从ModelMap中取值：[key=defModelAttributeName, value=" + modelAttr + "].");
        return new ModelAndView("webannotations/ModelAttribute", modelMap);
    }

}

package com.arhorchin.securitit.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.lang.Nullable;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.alibaba.fastjson.JSON;

/**
 * @author Securitit.
 * @note @ModelAttribute查看ModelMap测试.
 */
public class ModelAttributeHandlerInterceptor implements HandlerInterceptor {

    /**
     * logger.
     */
    private Logger logger = LoggerFactory.getLogger(ModelAttributeHandlerInterceptor.class);

    /**
     * 在HandlerAdapter实际调用处理程序之后调用，但在DispatcherServlet呈现视图之前调用.
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            @Nullable ModelAndView modelAndView) throws Exception {
        logger.info("==============================ModelAttributeHandlerInterceptor postHandle==============================\n"
                + JSON.toJSONString(modelAndView.getModelMap(), true));
    }

}