java BufferedWriter 產生新檔案

//新檔案蓋掉舊檔案
BufferedWriter bw = new BufferedWriter(new FileWriter("test.txt"));

//寫入的資料附加在原來的檔案
BufferedWriter bw = new BufferedWriter(new FileWriter("test.txt",true));

bw.write(childs);
bw.newLine();
bw.close();