带有模棱两可关闭的groovy : How to resolve

Question

我正在尝试在 groovy 中做到这一点

def results = new File(someDirectory).listFiles { it.name.startsWith 'foo'}

但是，我得到了可以理解的错误:

groovy.lang.GroovyRuntimeException: Ambiguous method overloading for method java.io.File#listFiles.
Cannot resolve which method to invoke for [class change$_getRollback_closure1] due to overlapping prototypes between:
    [interface java.io.FileFilter]
    [interface java.io.FilenameFilter]

我如何告诉它使用带有 FileFilter 的那个？

我最终写了它普通的 Java 风格:

File[] files = someDir.listFiles( new FileFilter(){
    @Override
    boolean accept(File pathname) {
        return pathname.name.startsWith("foo")
    }
})

Answer 1

您可以强制转换或强制闭包以指定您所指的 SAM 类型/功能接口(interface)。

// using a typecast:
def results = new File(someDirectory).listFiles((FileFilter) { it.name.startsWith 'foo'})

// using as keyword:
def results = new File(someDirectory).listFiles({ it.name.startsWith 'foo'} as FileFilter)

// using SAM-type coercion:
FileFilter ff = { it.name.startsWith 'foo'}
def results = new File(someDirectory).listFiles(ff)