java讀文件，文件中包含不同用戶，根據用戶的不同將數據讀到不同文件！求一個簡單的java demo！第一個字段代表用戶id：
2 回答
Qyouu
TA貢獻1786條經驗 獲得超11個贊
這樣？
Map bWriters = new HashMap<>();
try(BufferedReader bReader = new BufferedReader(new FileReader("fileName"))) {
String tStr = null;
while ((tStr = bReader.readLine()) != null){
String[] strs = tStr.split(",");
String usrId = strs[0];
BufferedWriter bWriter = bWriters.get(usrId);
if(bWriter == null){
bWriter = new BufferedWriter(new FileWriter("targetFileName"));
bWriters.put(usrId, bWriter);
}
bWriter.write(tStr);
}
} catch (IOException e) {
e.printStackTrace();
}finally {
if(bWriters!=null){
for(BufferedWriter bw:bWriters.values()){
try {
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
