我正在嘗試讀取文件并計(jì)算文件中的行數(shù)。每行都有一個(gè)電影標(biāo)題。我注釋掉了增加計(jì)數(shù)的行。如果我取消注釋計(jì)數(shù)的遞增，程序就會(huì)掛起并且永遠(yuǎn)不會(huì)打印計(jì)數(shù)。我究竟做錯(cuò)了什么？如果我只打印 while 循環(huán)中的每一行，它就可以正常工作。但如果我嘗試增加計(jì)數(shù)則不會(huì)。謝謝。import java.io.FileNotFoundException;import java.util.Scanner;import java.io.File;public class GuessTheMovie { public static void main(String[] args) throws Exception { try { File file = new File("movies.txt"); Scanner scanner = new Scanner(file); // open movies file and count the number of titles in the file int count = 0; while (scanner.hasNextLine()) { //count += 1; System.out.println(scanner.nextLine()); } System.out.println(count); // create String array of movies such that the size is equal to the number of movies in file. //String [] movies = [] } catch (Exception e) { System.out.println("Could not find file."); } }}
4 回答
萬(wàn)千封印
TA貢獻(xiàn)1891條經(jīng)驗(yàn) 獲得超3個(gè)贊
假設(shè)您不知道格式如何，movies.txt我建議您執(zhí)行以下操作：
將內(nèi)容附加到
StringBuilderString用的內(nèi)容做一個(gè)StringBuilder得到想要的數(shù)據(jù)
這是一個(gè)小演示，對(duì)我有用。
//make sure you are using the "relative path" to find the movies.txt file(as follows)
?try (BufferedReader br = new BufferedReader(new FileReader("./movies.txt"))) {
? ? ? ?StringBuilder sb = new StringBuilder();
? ? ? ?String responseLine = null;
? ? ? ?while ((responseLine = br.readLine()) != null) {
? ? ? ? ? ? ? ? ? ? ?sb.append(responseLine.trim());
? ? ? ? }
? ? ? ? System.out.println(sb);
? ? ? ?//By now you should have all movies & titles to your StringBuilder instance then
? ? ? ? String temp = sb.toString();
? ? ? ? String movies[] = temp.split(" ");//split the string at "spaces"
? ? ? ? System.out.println("First Element: "+movies[0]);
? ? ? ? System.out.println("Second Element: "+movies[1]);
? ? ? ? System.out.println("Third Element: "+movies[2]);
? ? ? ? } catch (Exception e) {
? ? ? ? System.out.println("Could not find file.");
?}
這是我的內(nèi)容movies.txt
注意：
String按照您想要的方式拆分內(nèi)容
如果你正確分割它
movies.length會(huì)給你電影的數(shù)量
輸出
手掌心
TA貢獻(xiàn)1942條經(jīng)驗(yàn) 獲得超3個(gè)贊
在這里，我為您準(zhǔn)備了工作代碼。它正在從 filereader 讀取文件，而 st 是等于每一行的參數(shù)。在循環(huán)中，它將遍歷每一行并計(jì)算行數(shù)。
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.File;
public class FileRead {
public static void main(String[] args) throws Exception {
File file = new File("C:\\Users\\Name\\Desktop\\test.txt");
String st;
BufferedReader br = new BufferedReader(new FileReader(file));
int count = 0;
while ((st = br.readLine()) != null) {
count++;
}
System.out.println(count);
}
}
弒天下
TA貢獻(xiàn)1818條經(jīng)驗(yàn) 獲得超8個(gè)贊
試試下面的代碼
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.File;
public class GuessTheMovie {
public static void main(String[] args) throws Exception {
try {
File file = new File("movies.txt");
Scanner scanner = new Scanner(file);
// open movies file and count the number of titles in the file
int count = 0;
while (scanner.hasNextLine()) {
count += 1;
scanner.nextLine();
}
System.out.println(count);
// create String array of movies such that the size is equal to the number of movies in file.
//String [] movies = []
} catch (Exception e) {
System.out.println("Could not find file.");
}
}
}
肥皂起泡泡
TA貢獻(xiàn)1829條經(jīng)驗(yàn) 獲得超6個(gè)贊
如果您想嘗試，可以使用更簡(jiǎn)單的方式與文件交互：
List<String> lines = Files.readAllLines(Paths.get(path), Charset.defaultCharset());
之后，您可以與準(zhǔn)備好的所有行列表進(jìn)行交互，或者使用lines.size().
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