文本文件Buffered Reader

Question

如何將我的代碼中的緩衝讀取器更改爲Scanner，因爲我不允許使用BufferedReader？或者甚至有可能？

public static void Option3Method() throws IOException 
{ 
    FileReader fr = new FileReader("wordlist.txt"); 
    BufferedReader br = new BufferedReader(fr); 
    String s; 
    String words[]=new String[500]; 
    String word = JOptionPane.showInputDialog("Enter a word to search for"); 
    while ((s=br.readLine())!=null) 
    { 
    int indexfound=s.indexOf(word); 
    if (indexfound>-1) 
    { 
     JOptionPane.showMessageDialog(null, "Word was found"); 
    } 
    else if (indexfound<-1) 
    { 
     JOptionPane.showMessageDialog(null, "Word was not found");} 
    } 
    fr.close(); 
    } 
} 

Answer 1

更換

FileReader fr = new FileReader("wordlist.txt"); BufferedReader br = new BufferedReader(fr);

與

Scanner scan = new Scanner(new File("wordlist.txt"));

而更換

while ((s=br.readLine())!=null) {

與

while (scan.hasNext()) { 

      s=scan.nextLine(); 
     } 

Answer 2

如果你看一下掃描儀類，你可以看到它有一個構造函數一個文件，這反過來又可以用字符串路徑被實例化。 Scanner類具有與readLine（）（即nextLine（））類似的方法。

Answer 3

您可以使用constructor of scanner that takes a file，然後使用nextLine()讀取使用該掃描儀的行。要檢查是否有更多的線要閱讀使用hasNextLine()

Answer 4

沒有測試它，但它應該工作。

public static void Option3Method() throws IOException 
{ 
    Scanner scan = new Scanner(new File("wordlist.txt")); 
    String s; 
    String words[]=new String[500]; 
    String word = JOptionPane.showInputDialog("Enter a word to search for"); 
    while (scan.hasNextLine()) 
    { 
    s = scan.nextLine(); 
    int indexfound=s.indexOf(word); 
    if (indexfound>-1) 
    { 
     JOptionPane.showMessageDialog(null, "Word was found"); 
    } 
    else if (indexfound<-1) 
    { 
     JOptionPane.showMessageDialog(null, "Word was not found");} 
    } 
    } 
}