从文件中获取行号
从文件中获取行号
提问于 2013-07-14 11:02:55
我如何实现一个方法来返回当前从文件扫描的行号。我有两个扫描器，一个用于文件(fileScanner)，另一个用于行(lineScanner)
这就是我所拥有的，但我不知道是否需要构造函数中的行号！
public TextFileScanner(String fileName) throws FileNotFoundException
{
this.fileScanner = new Scanner(new File(fileName));
this.lineScanner = new Scanner(this.fileScanner.nextLine());
this.lineNumber = 1;
}我需要这个方法：
public int getLineNumber()
{
}回答 1
Stack Overflow用户
发布于 2013-07-14 11:50:38
您可以只使用一个Scanner对象来读取文件并报告行号。
下面是一个示例代码：
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class LineNumber {
public static void main(String [] args) throws FileNotFoundException {
System.out.printf("Test!\n");
File f = new File("test.txt");
Scanner fileScanner = new Scanner(f);
int lineNumber = 0;
while(fileScanner.hasNextLine()){
System.out.println(fileScanner.nextLine());
lineNumber++;
}
fileScanner.close();
System.out.printf("%d lines\n", lineNumber);
}
}现在，如果你想使用面向对象的编程方法来实现这一点，那么你可以这样做：
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class FileProcessor {
// Mark these field as private so the object won't get tainted from outside
private String fileName;
private File file;
/**
* Instantiates an object from the FileProcessor class
*
* @param fileName
*/
public FileProcessor(String fileName) {
this.fileName = fileName;
this.file = new File(fileName);
}
public int getLineNumbers() {
Scanner fileScanner = null;
try {
fileScanner = new Scanner(this.file);
} catch (FileNotFoundException e) {
System.out.printf("The file %s could not be found.\n",
this.file.getName());
}
int lines = 0;
while (fileScanner.hasNextLine()) {
lines++;
// Go to next line in file
fileScanner.nextLine();
}
fileScanner.close();
return lines;
}
/**
* Test our FileProcessor Class
*
* @param args
* @throws FileNotFoundException
*/
public static void main(String[] args) throws FileNotFoundException {
FileProcessor fileProcessor = new FileProcessor("text.txt");
System.out.printf("%d lines\n", fileProcessor.getLineNumbers());
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/17636157
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