需求：

将http报文请求(保护body和url)中的参数传递给Controller时支持使用别名。

举例：

下面两条请求报文的结果是一致的。

http://example.com/foo?jobType=permanent&location=Stockholm

http://example.com/foo?jt=permanent&loc=Stockholm

返回响应

解决方法

 Spring MVC3 提供了丰富的参数映射机制， 

同时对于Spring MVC默认的提供的映射机制不能涵盖的对象，我们可以通过扩展HandlerMethodArgumentResolver和HttpMessageConverter的机制来实现。

HandlerMethodArgumentResolver对应输入， HttpMessageConverter对应输出

1.预备代码

package com.davidwang456.web.model;import com.davidwang456.web.annotation.ParamName;public class Job {    @ParamName("jt")    private String jobType;    @ParamName("loc")    private String location;    public String getJobType() {        return jobType;    }    public void setJobType(String jobType) {        this.jobType = jobType;    }    public String getLocation() {        return location;    }    public void setLocation(String location) {        this.location = location;    }        @Override    public String toString(){        return "jobType="+jobType+",location="+location;    }    }

2.注解

package com.davidwang456.web.annotation;import java.lang.annotation.Documented;import java.lang.annotation.Retention;import java.lang.annotation.Target;import java.lang.annotation.ElementType;import java.lang.annotation.RetentionPolicy;/** * Overrides parameter name */@Target(ElementType.FIELD)@Retention(RetentionPolicy.RUNTIME)@Documentedpublic @interface ParamName {    /**     * The name of the request parameter to bind to.     */    String value();}

3.注解处理器

package com.davidwang456.web.processor;import java.lang.reflect.Field;import java.util.Collections;import java.util.HashMap;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.WebDataBinder;import org.springframework.web.context.request.NativeWebRequest;import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;import org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor;import com.davidwang456.web.annotation.ParamName;/** * Method processor supports {
    @link ParamName} parameters renaming * */public class RenamingProcessor extends ServletModelAttributeMethodProcessor {    @Autowired    private RequestMappingHandlerAdapter requestMappingHandlerAdapter;    //Rename cache    private final Map
     
      , Map
      
       > replaceMap = new ConcurrentHashMap
       
        , Map
        
         >();    public RenamingProcessor(boolean annotationNotRequired) {        super(annotationNotRequired);    }    @Override    protected void bindRequestParameters(WebDataBinder binder, NativeWebRequest nativeWebRequest) {        Object target = binder.getTarget();        Class
          targetClass = target.getClass();        if (!replaceMap.containsKey(targetClass)) {            Map
         
           mapping = analyzeClass(targetClass);            replaceMap.put(targetClass, mapping);        }        Map
          
            mapping = replaceMap.get(targetClass); ParamNameDataBinder paramNameDataBinder = new ParamNameDataBinder(target, binder.getObjectName(), mapping); requestMappingHandlerAdapter.getWebBindingInitializer().initBinder(paramNameDataBinder, nativeWebRequest); super.bindRequestParameters(paramNameDataBinder, nativeWebRequest); } private static Map
           
             analyzeClass(Class
             targetClass) { Field[] fields = targetClass.getDeclaredFields(); Map
            
              renameMap = new HashMap
             
              (); for (Field field : fields) { ParamName paramNameAnnotation = field.getAnnotation(ParamName.class); if (paramNameAnnotation != null && !paramNameAnnotation.value().isEmpty()) { renameMap.put(paramNameAnnotation.value(), field.getName()); } } if (renameMap.isEmpty()) return Collections.emptyMap(); return renameMap; }}
             
            
           
          
         
        
       
      
     

4.数据绑定

package com.davidwang456.web.processor;import java.util.Map;import javax.servlet.ServletRequest;import org.springframework.beans.MutablePropertyValues;import org.springframework.web.servlet.mvc.method.annotation.ExtendedServletRequestDataBinder;/*** ServletRequestDataBinder which supports fields renaming using {
    @link ParamName}**/public class ParamNameDataBinder extends ExtendedServletRequestDataBinder {   private final Map
     
       renameMapping;   public ParamNameDataBinder(Object target, String objectName, Map
      
        renameMapping) {       super(target, objectName);       this.renameMapping = renameMapping;   }   @Override   protected void addBindValues(MutablePropertyValues mpvs, ServletRequest request) {       super.addBindValues(mpvs, request);       for (Map.Entry
       
         entry : renameMapping.entrySet()) {           String from = entry.getKey();           String to = entry.getValue();           if (mpvs.contains(from)) {               mpvs.add(to, mpvs.getPropertyValue(from).getValue());           }       }   }}
       
      
     

5.注册处理器

或者java config模式

package com.davidwang456.web.configurer;import java.util.List;import org.springframework.context.annotation.Configuration;import org.springframework.web.method.support.HandlerMethodArgumentResolver;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import com.davidwang456.web.processor.RenamingProcessor;@Configuration@EnableWebMvcpublic class WebConfig extends WebMvcConfigurerAdapter{      @Override      public void addArgumentResolvers(List
     
       argumentResolvers) {          RenamingProcessor renameResolver = new RenamingProcessor(true);          argumentResolvers.add(renameResolver);      }}
     

 

参考文献：

【1】http://stackoverflow.com/questions/8986593/how-to-customize-parameter-names-when-binding-spring-mvc-command-objects

【2】http://geekabyte.blogspot.tw/2014/08/how-to-inject-objects-into-spring-mvc.html

【3】http://www.cnblogs.com/daxin/p/3296493.html