文本文件Buffered Reader

Question

如何将我的代码中的缓冲读取器更改为Scanner，因为我不允许使用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

更换

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

与

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

而更换

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

与

while (scan.hasNext()) { 

      s=scan.nextLine(); 
     } 

Answer 2

如果你看一下扫描仪类，你可以看到它有一个构造函数一个文件，这反过来又可以用字符串路径被实例化。 Scanner类具有与readLine（）（即nextLine（））类似的方法。

Answer 3

您可以使用constructor of scanner that takes a file，然后使用nextLine()读取使用该扫描仪的行。要检查是否有更多的线要阅读使用hasNextLine()

Answer 4

没有测试它，但它应该工作。

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");} 
    } 
    } 
}