在Java中一次读取多行

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class MultiLineReader {

    public static void main(String[] args) {
        try {
            BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
            String line;
            StringBuilder content = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                content.append(line);
                content.append(System.lineSeparator());
            }
            reader.close();
            
            System.out.println(content.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}