文件拷贝工具类

https://docs.spring.io/spring/docs/1.2.x/javadoc-api/org/springframework/util/FileCopyUtils.html

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.3.1.RELEASE</version>
        </dependency>

用法举例：

    @Test
    public void tt() throws IOException{
        FileCopyUtils.copy(new File("E:\abc.txt"), new File("E:\abcd.txt"));
    }