有時候，爲了快速複製很多文件裏的內容合併到一個文件中，則可以採用如下方式：
public class CodeOutput {
public static void main(String[] args) throws Exception {
// 需要遍歷的文件夾
String fileDirectory = "E:\\doc";
// 包含的文件名後綴
String includeFileNameSuffix = ".java";
// 輸出的文件名
String outputFilePath = "D:/code.txt";
Path startingDir = Paths.get(fileDirectory);
FindFileVisitor findJavaVisitor = new FindFileVisitor(includeFileNameSuffix);
Files.walkFileTree(startingDir, findJavaVisitor);
try {
FileOutputStream fos = new FileOutputStream(outputFilePath);
FileChannel channel = fos.getChannel();
findJavaVisitor.getFileNameList().forEach(name -> {
System.out.println(name);
if (!name.endsWith("CodeOutput.java")) {
Path path = Paths.get(name);
try {
byte[] bytes = Files.readAllBytes(path);
channel.write(ByteBuffer.wrap(bytes));
} catch (IOException e) {
e.printStackTrace();
}
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
static class FindFileVisitor extends SimpleFileVisitor<Path> {
private String fileNameSuffix;
public FindFileVisitor(String fileNameSuffix) {
this.fileNameSuffix = fileNameSuffix;
}
private List<String> fileNameList = new ArrayList<>();
public List<String> getFileNameList() {
return fileNameList;
}
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
String fileName = file.toString();
if (fileName.endsWith(fileNameSuffix)) {
fileNameList.add(fileName);
}
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
return FileVisitResult.CONTINUE;
}
}
}