Question

我知道我可以使用匿名方法或lambda表达式，例如：

master

但是我无法弄清楚是否可以使用常规委托（委托bool X（MyObject o）），我的尝试失败了。

即创建委托，将其设置为方法a，然后将委托实例作为谓词传递。

Answer 1

出于兼容性的原因，即使其他委托的签名兼容，也必须显式实例化委托。记录的文档不是很好，请参见this question中的讨论。

（非常冗长）语法的示例执行此操作：

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /insert
       Parameters = {}
          Headers = {Content-Type=[application/json;charset=UTF-8], Accept=[application/json;charset=UTF-8]}
             Body = {"bin":"123456", "json_full":"{'brand':'visa', 'type':'credit', 'country':'USA', 'issuer':'BigBank'}", "brand":"visa", "type":"credit", "country":"USA", "issuer":"BigBank", "newObject":"true", "new":"true", "createdAt":"18/08/2018 02:00:00 +0200", "updatedAt":"18/08/2018 02:00:00 +0200"}
    Session Attrs = {}

Handler:
             Type = com.xxxxx.binlookup.controller.BinInfoController
           Method = public org.springframework.http.ResponseEntity<java.lang.Object> com.xxxxx.binlookup.controller.BinInfoController.insertBIN(com.xxxxx.binlookup.model.BinInfo,javax.servlet.http.HttpServletResponse) throws com.fasterxml.jackson.core.JsonProcessingException

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = null

ModelAndView:
        View name = null
             View = null
            Model = null

FlashMap:
       Attributes = null

MockHttpServletResponse:
           Status = 201
    Error message = null
          Headers = {Content-Type=[application/json;charset=UTF-8]}
     Content type = application/json;charset=UTF-8
             Body = {"id":"123456","newObject":false,"new":false,"bin":"123456","json_full":"{'brand':'visa', 'type':'credit', 'country':'USA', 'issuer':'BigBank'}","brand":"visa","type":"credit","country":"USA","issuer":"BigBank","createdAt":"18/08/2018 02:00:00 +0200","updatedAt":"18/08/2018 02:00:00 +0200"}
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

我可以使用标准委托代替谓词吗？

1 个答案: