Java 文件行数计算

public class FileLineNumberSearch {
    public static void main(String[] args) {
        String filePath = new File("").getAbsolutePath() + "/src/file/" + "waitUse" + ".txt";
        // readLine方式
        try{
            File file =new File(filePath);
            if(file.exists()){
                FileReader fr = new FileReader(file);
                LineNumberReader lnr = new LineNumberReader(fr);
                int linenumber = 0;
                while (lnr.readLine() != null){
                    linenumber++;
                }
                System.out.println("Total number of lines : " + linenumber);
                lnr.close();
            }else{
                System.out.println("No File Found!");
            }
        }catch(IOException e){
            e.printStackTrace();
        }

        // getLineNumber方式
        try {
            File file = new File(filePath);
            if(file.exists()){
                long fileLength = file.length();
                LineNumberReader lineNumberReader = new LineNumberReader(new FileReader(file));
                lineNumberReader.skip(fileLength);//行号从0开始
                int lines = lineNumberReader.getLineNumber() + 1;
                System.out.println("Total number of lines : " + lines);
                lineNumberReader.close();
            }else {
                System.out.println("No File Found!");
            }
        }catch(IOException e) {
            e.printStackTrace();
        }

        // lines方式
        try {
            long lines = Files.lines(Paths.get(new File(filePath).getPath())).count();
            System.out.println("Total number of lines : " + lines);
            long endTime=System.currentTimeMillis();
        } catch (IOException e) {
            System.out.println("No File Found!");
        }
    }



}