JAVA功能代码-高效读取txt文本

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;

/**
 * TODO
 *
 * @Author seems
 * @Date 2021/5/28 下午 09:07
 */
public class FileUntils {
    // 高效读取txt文本
    public static String getTxtContent(File file, Charset charset) throws IOException {
        Path path = file.toPath();
        // 一个文本文件如果已经大于int最大值，这种文件一般来说很少见有可能是log文件 
        if (file.length() <= Integer.MAX_VALUE - 8) {
            // 使用nio提高读取速度
            try (FileChannel in = FileChannel.open(path, StandardOpenOption.READ)) {
                ByteBuffer byteBuffer = ByteBuffer.allocate((int) in.size());
                in.read(byteBuffer);
                in.close();
                System.out.println(byteBuffer);
                System.out.println(byteBuffer.array());
                return new String(byteBuffer.array(), charset);
            }
        }
        StringBuilder msg = new StringBuilder();
        try (BufferedReader reader = Files.newBufferedReader(path, charset)) {
            for (; ; ) {
                String line = reader.readLine();
                if (line == null) {
                    break;
                }
                msg.append(line);
            }
        }
        return msg.toString();
    }

    public static String getTxtContent(File file) throws IOException {
        FileReader fr = null;
        BufferedReader br = null;
        StringBuffer txt = new StringBuffer();
        try {
            fr = new FileReader(file);
            br = new BufferedReader(fr);
            String line = null;
            while ((line = br.readLine()) != null) {
                txt.append(line);
                txt.append("\n");
            }
            br.close();
            fr.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fr != null) {
                try {
                    fr.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return txt.toString();
    }
    // 读取文件名
    public static void getFileName(String path){
    // get file list where the path has
    File file = new File(path);
    // get the folder list
    File[] array = file.listFiles();

    for(int i=0;i<array.length;i++){
        if(array[i].isFile()){
            System.out.println(array[i].getName());
            System.out.println(array[i]);
            System.out.println(array[i].getPath());
        }else if(array[i].isDirectory()){
            getFileName(array[i].getPath());
        }
    }
}
}