Question

我遇到了Spring 4.2.5和java8的问题。

尝试写简单的休息：

@RequestMapping(value = "raw2", method = RequestMethod.GET)
ResponseEntity<String> getTest(@RequestParam Optional<String> p) {
    return new ResponseEntity<>(HttpStatus.OK);
}

但不断收到错误：

2016-04-05 20:51:41,436 DEBUG [o.s.web.servlet.DispatcherServlet] DispatcherServlet with name 'dispatcher' processing GET request for [/internal/raw2]
2016-04-05 20:51:41,438 DEBUG [o.s.w.s.m.a.DefaultAnnotationHandlerMapping] Mapping [/internal/raw2] to HandlerExecutionChain with handler [com.test.con] and 1 interceptor
2016-04-05 20:51:41,440 DEBUG [o.s.web.servlet.DispatcherServlet] Last-Modified value for [/internal/raw2] is: -1
2016-04-05 20:51:41,453 DEBUG [org.springframework.beans.BeanUtils] No property editor [java.util.OptionalEditor] found for type java.util.Optional according to 'Editor' suffix convention   
2016-04-05 20:51:41,453 DEBUG [o.s.w.s.m.a.AnnotationMethodHandlerExceptionResolver] Resolving exception from handler [com.test.con]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type [java.lang.String] to required type  [java.util.Optional]; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [java.util.Optional]: no matching editors or conversion strategy found
2016-04-05 20:51:41,454 DEBUG [o.s.w.s.m.a.ResponseStatusExceptionResolver] Resolving exception from handler [com.test.con]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type [java.lang.String] to required type [java.util.Optional]; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [java.util.Optional]: no matching editors or conversion strategy found
2016-04-05 20:51:41,454 DEBUG [o.s.w.s.m.s.DefaultHandlerExceptionResolver] Resolving exception from handler [com.test.con]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type [java.lang.String] to required type [java.util.Optional]; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [java.util.Optional]: no matching editors or conversion strategy found
2016-04-05 20:51:41,454 WARN  [o.s.w.s.m.s.DefaultHandlerExceptionResolver] Failed to convert request element: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type [java.lang.String] to required type [java.util.Optional]; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [java.util.Optional]: no matching editors or conversion strategy found

Answer 1

确保您已在XML中添加了<mvc:annotation-driven>标记。这将确保转换器可用

java8 spring 4.2.5无法转换为java.util.Optional

1 个答案: