首頁(yè) 猿問從文件中讀取 N 行并將其保存到新文件中

從文件中讀取 N 行并將其保存到新文件中

Java

動(dòng)漫人物 2022-05-21 20:55:02

例如，如何讀取 20 行readFile或 n 行并將其保存到另一個(gè)文件（writeFile）？public class Test_read_file { public static List<String> readFile() throws IOException { try(BufferedReader br = new BufferedReader(new FileReader("C:\\\\\\\\Users\\\\\\\\Admin\\\\\\\\Desktop\\\\\\\\Work Files\\\\\\\\314-WO0000001133814\\\\\\\\Cards\\\\\\\\MBD10760_182.out"))){ List<String> listOfData = new ArrayList<>(); String d; while((d = br.readLine()) != null){ listOfData.add(d); } return listOfData; }}public static void writeFile(List<String> listOfData) throws IOException{ try(BufferedWriter bw = new BufferedWriter(new FileWriter("C:\\\\\\\\Users\\\\\\\\Admin\\\\\\\\Desktop\\\\\\\\Work Files\\\\\\\\314-WO0000001133814\\\\\\\\Cards\\\\\\\\MBD10760_187.out"))){ for(String str: listOfData){ bw.write(str); bw.newLine(); } }}public static void main(String[] args) throws IOException { List<String> data = readFile(); writeFile(data);}}

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3 回答

梵蒂岡之花

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假設(shè)您的代碼工作正常：

public static List<String> readFile(int n) throws IOException {

try(BufferedReader br = new BufferedReader(new

FileReader("C:\\\\\\\\Users\\\\\\\\Admin\\\\\\\\Desktop\\\\\\\\Work Files\\\\\\\\314-

WO0000001133814\\\\\\\\Cards\\\\\\\\MBD10760_182.out"))){

List<String> listOfData = new ArrayList<>();

String d;

while((d = br.readLine()) != null && n>0){

listOfData.add(d);

n--;

}

return listOfData;

}

只是你必須告訴循環(huán)它應(yīng)該讀多少行。如果文件少于 n 行，則 while 循環(huán)的第一條語(yǔ)句將返回 null 并中斷循環(huán)。否則，當(dāng)它讀取 n 行時(shí)，由于 while 循環(huán)中的第二條語(yǔ)句，它將再次中斷循環(huán)

反對(duì) 回復(fù) 2022-05-21