webservice里的@queryparam、@pathparam、@DefaultValue使用介绍

1 先来看@queryparam
   先看例子:
 

Path("/users") 
public class UserService { 
  
    @GET 
    @Path("/query") 
    public Response getUsers( 
        @QueryParam("from") int from, 
        @QueryParam("to") int to, 
        @QueryParam("orderBy") List orderBy) { 
  
        return Response 
           .status(200) 
           .entity("getUsers is called, from : " + from + ", to : " + to 
            + ", orderBy" + orderBy.toString()).build(); 
  
    } 
  
} 

 URL输入为:

users/query?from=100&to=200&orderBy=age&orderBy=name

  此时,输出为:

getUsers is called, from : 100, to : 200, orderBy[age, name]

   要注意的是,跟@pathparam不同,@queryparam
中,指定的是URL中的参数是以键值对的形式出现的,而在程序中
@QueryParam("from") int from则读出URL中from的值,
而@pathparem中,URL中只出现参数的值,不出现键值对,比如:
“/users/2011/06/30” 则:

@GET 
    @Path("{year}/{month}/{day}") 
    public Response getUserHistory( 
            @PathParam("year") int year, 
            @PathParam("month") int month,  
            @PathParam("day") int day) { 
  
       String date = year + "/" + month + "/" + day; 
  
       return Response.status(200) 
        .entity("getUserHistory is called, year/month/day : " + date) 
        .build(); 
  
    } 

输出为:

getUserHistory is called, year/month/day : 2011/6/30

2 以动态的方式获得:

@Path("/users") 
public class UserService { 
  
    @GET 
    @Path("/query") 
    public Response getUsers(UriInfo info) { 
  
        String from = info.getQueryParameters().getFirst("from"); 
        String to = info.getQueryParameters().getFirst("to"); 
        List orderBy = info.getQueryParameters().get("orderBy"); 
  
        return Response 
           .status(200) 
           .entity("getUsers is called, from : " + from + ", to : " + to 
            + ", orderBy" + orderBy.toString()).build(); 
  
    }
} 

输入为：

URL;users/query?from=100&to=200&orderBy=age&orderBy=name

输出为:

getUsersis called, from : 100, to : 200, orderBy[age, name]

注意这里把orderby后的两个参数读入为LIST处理了.

3 @DefaultValue,默认值

  例子:

@Path("/users") 
public class UserService { 
  
    @GET 
    @Path("/query") 
    public Response getUsers( 
        @DefaultValue("1000")@QueryParam("from") int from, 
       @DefaultValue("999")@QueryParam("to") int to, 
        @DefaultValue("name")@QueryParam("orderBy") List orderBy) { 
  
        return Response 
           .status(200) 
          .entity("getUsers is called, from : " + from + ", to : " +to 
            + ",orderBy" + orderBy.toString()).build(); 
  
    } 

输入：

URL:users/query

输出:

getUsers is called, from : 1000, to : 999,orderBy[name]