Java实现复制并修改部分文件后缀名

public class Test {

    public static String DIR = "e:\\Test\\java";//需要复制的源文件地址

    public static String DESTDIR = "e:\\Test\\aaa";//拷贝后存放的地址

    public static void main(String[] args) throws Exception { 

    System.out.println("开始");

    traverseFolder(DIR);

    System.out.println("结束");

    } 


    public static void copy(InputStream in, OutputStream out) throws Exception { 

        byte[] buf = new byte[1024]; 

        int len = 0; 

        /*读取文件内容并写入文件字节流中*/ 

        while((len = in.read(buf))!=-1) { 

            out.write(buf, 0, len); 

        } 

    } 


    public static void traverseFolder(String path) throws Exception {

    File file = new File(path);

        if (file.exists()) {

            File[] files = file.listFiles();

            if (files.length == 0) {

                System.out.println(file.getAbsolutePath() + " 空文件夹!");

                return;

            } else {

                for (File file2 : files) {

                    if (file2.isDirectory()) {

                    //如果是文件夹创建文件夹

                    File str = new File(file2.getAbsolutePath().toString().replace(DIR, DESTDIR));

                    str.mkdir();

                    //递归查找该文件夹里面的文件                   

                        traverseFolder(file2.getAbsolutePath());

                    }else {

                    FileInputStream fis = new FileInputStream(file2); 

                    //修改后缀名(java改txt)

                    String destFileName = file2.getName().replaceAll("\\.java$", "\\.txt"); 

                    FileOutputStream fos = new FileOutputStream(new File(file2.getParent().toString().replace(DIR, DESTDIR), destFileName)); 

                    //复制写入

                    copy(fis, fos); 

                    fis.close(); 

                    fos.close();

                    }

                }

            }

        } else {

            System.out.println("文件不存在!");

        }

    }

}