java中遍歷文件，再將txt文件聚合到一起

import java.io.*;
import java.util.ArrayList;

/**
 * 將oldPath這個目錄下的所有txt文件遍歷讀取
 * 然後全部放到newFile這個文件裏
 * 
 */
public class GetSome {
    ArrayList<String> listPath = new ArrayList<>();
    ArrayList<String> listFile = new ArrayList<>();

    public static void main(String[] args) throws IOException {
        GetSome getSome = new GetSome();

        String oldPath = "C:\\Users\\Desktop\\agent";
        String newFile = "C:\\Users\\Desktop\\1.txt";

        //得到oldpath目錄下的所有txt文件目錄
        getSome.copyPath(oldPath,getSome);
        //讀取所有txt文件裏的內容
        getSome.readFilePath(getSome.listPath,getSome);
        //將txt文件裏的內容寫入newFile文件
        getSome.writeFile(getSome.listFile,newFile);
    }

    public void writeFile(ArrayList<String> list,String path) throws IOException {
        File file = new File(path);
        if (!file.exists()){
            file.createNewFile();
        }

        BufferedWriter bw = new BufferedWriter(new FileWriter(path));
        for (String str:list){
            bw.write(str + "\n");
            bw.flush();
        }
        bw.close();
    }

    public void readFilePath(ArrayList<String> listPath,GetSome getSome) throws IOException {
        for (String str:listPath){
            getSome.readfile(str,getSome);
        }
    }

    public void readfile(String path,GetSome getSome) throws IOException {
        if (!path.contains(".txt")){
            return;
        }
        BufferedReader br = new BufferedReader(new FileReader(path));
        String str = br.readLine();
        while (str != null){
            getSome.listFile.add(str);
            str = br.readLine();
        }
    }

    public void copyPath(String path,GetSome getSome) {

        File file = new File(path);
        if (file.exists()) {
            File[] files = file.listFiles();
            if (null == files || files.length == 0) {
                System.out.println("文件夾是空的!");
                return;
            } else {
                for (File file2 : files) {
                    if (file2.isDirectory()) {
                        copyPath(file2.getAbsolutePath(),getSome);
                    } else {
                        getSome.listPath.add(file2.getAbsolutePath());
//                        System.out.println("文件:" + file2.getAbsolutePath());
                    }
                }
            }
        } else {
            System.out.println("文件不存在!");
        }
    }

}