把一个文件夹内后缀是.java的文件复制到另文件夹内 - 黑马程序员技术交流社区

public class Test09 {
public static void main(String[] args) {
ArrayList<File> arrList = new ArrayList<File>();
//源文件躲在路径
File file = new File("E:\\StudyFile");
fileToList(file, arrList);
writeToFile(arrList);
}
//把源文件后缀是.java的文件写到List集合内
public static void fileToList(File dir, List<File> list) {
File[] files = dir.listFiles();
for (File file : files) {
if (file.isDirectory()) {
fileToList(file, list);
} else {
if (file.getName().endsWith(".java")) {
list.add(file);
}
}
}
}
//把List集合内的文件写到目的文件夹e:\\targetFile
public static void writeToFile(List<File> list) {
File targetFile = new File("e:\\targetFile");
// 不存在则创建新目录
if (!targetFile.exists()) {
targetFile.mkdir();
}
BufferedReader bur = null;
BufferedWriter buw = null;
String s;
for (File file : list) {
try {
bur = new BufferedReader(new InputStreamReader(
new FileInputStream(file)));
// 后缀名替换
String targetFileName = file.getName().replaceAll(".java",".txt");
buw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(targetFile,targetFileName))));
while ((s = bur.readLine()) != null) {
buw.write(s);
buw.newLine();
buw.flush();
}
} catch (Exception e) {
System.out.println("写入目的文件失败！！！");
}
try {
bur.close();
buw.close();
} catch (IOException e) {
System.out.println("关闭流失败！！");
}
}
System.out.println("复制成功！");
}
}

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