SpringMVC的参数类型转换-蒲公英云

SpringMVC的参数类型转换

package com.controller;
import java.util.Date;
import java.util.List;
import java.util.Map;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import com.entity.CollectionVO;
import com.entity.Person;
@Controller
@RequestMapping("/model2/")
public class HelloAnnotation3 {
    //SpringMVC参数类型转换
    //1.int String  http://localhost:8080/SpringMVCDemo/model2/m1?name=zhangsan&age=18
    @RequestMapping("m1")
    public String m1(int age,String name){
        System.out.println(age+","+name);
        //如果地址栏age参数为空，由于int不能接收null所以会报错，所以一般用包装类接收
        return "index";
    }
    //2.包装类Integer http://localhost:8080/SpringMVCDemo/model2/m2?age=18
    @RequestMapping("m2")
    public String m2(Integer age){
        System.out.println(age);
        return "index";
    }
    //3.数组  http://localhost:8080/SpringMVCDemo/model2/m3?arr=abc&arr=aaa&arr=hello
    @RequestMapping("m3")
    public String m3(String[] arr){
        System.out.println(arr.length);//3
        return "index";
    }
    //4.自定义类 http://localhost:8080/SpringMVCDemo/model2/m4?name=zhangsan&age=18
    @RequestMapping("m4")
    public String m4(Person p){
        System.out.println(p);
        System.out.println(p.getName()+","+p.getAge());
        return "index";//注意，容器自动将此处的person提交给视图层了
    }
    //以上都无需加参数注解
    //5.List http://localhost:8080/SpringMVCDemo/model2/m5?list=aa&list=bb
    @RequestMapping("m5")
    public String m5(@RequestParam List list){
        System.out.println(list.size());
        System.out.println(list);//[aa, bb]
        return "index";
    }
    //6.Map http://localhost:8080/SpringMVCDemo/model2/m6?k1=aaa&k2=bbb&k3=ccc
    @RequestMapping("m6")
    public String m6(@RequestParam Map map){
        System.out.println(map);//{k1=aaa, k2=bbb, k3=ccc}
        return "index";
    }
    //7.自定义复合对象类型，避免如5，6那样加注解，可以在entity中写一个CollectionVO封装
    //http://localhost:8080/SpringMVCDemo/model2/m7?list=aa&list=bb&map%5Bk1%5D=value1
    @RequestMapping("m7")
    public String m7(CollectionVO collectionVO){
        System.out.println(collectionVO.getList().size());//2
        //传map时，本来只用写map[k1]=value,但直接将中括号写在地址栏不解析，而应该写
        //左中括号%5B 右中括号%5D
        System.out.println(collectionVO.getMap());//{k1=value1}
        return "index";
    }
    //8.日期参数的处理，默认传参时是斜杠的形式  yyyy/MM/dd HH:mm:ss
    //http://localhost:8080/SpringMVCDemo/model2/m8?date=2018/8/8 20:30:59
    @RequestMapping("m8")
    public String m8(Date date){
        System.out.println(date);//Wed Aug 08 20:30:59 CST 2018
        return "index";
    }
    //9.自定义日期参数格式
    //http://localhost:8080/SpringMVCDemo/model2/m9?date=2018-8-8 20:30:59
    @RequestMapping("m9")
    public String m9(@DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss") Date date){
        //单纯加上述注解不起作用，还要补充一下注解驱动内容，详见springMVC-servlet.xml
        System.out.println(date);//Wed Aug 08 20:30:59 CST 2018
        return "index";
    }
}

自定义日期参数格式时，在springMVC-servlet.xml中加如下配置：

<!-- 自定义日期参数格式补充注解驱动内容 -->
<bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean"></bean>
<mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>

CollectionVO.java

package com.entity;
import java.util.List;
import java.util.Map;
public class CollectionVO {
    private List list;
    private Map map;
    public List getList() {
        return list;
    }
    public void setList(List list) {
        this.list = list;
    }
    public Map getMap() {
        return map;
    }
    public void setMap(Map map) {
        this.map = map;
    }
}