Java | 文件读写

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class Test {

    private static final Logger logger = LoggerFactory.getLogger(Test.class);

    //读取：FileReader
    //写入：FileWriter

    //读取内容
    public static String readTxt(File file) throws IOException {

        // 创建文件
        //file.createNewFile();

        FileReader fileReader = new FileReader(file);
        String s = "";
//        InputStreamReader in = new InputStreamReader(new FileInputStream(file),"UTF-8");
        BufferedReader br = new BufferedReader(fileReader);
        StringBuffer content = new StringBuffer();
        while ((s=br.readLine())!=null){
            content = content.append(s+"|");
        }
        return content.toString();
    }

    //写入内容
    public static Integer writeTxt(File file, List<String> lists) throws IOException {
        //file:写入对象,append:参数为true,则将字节写入文件末尾处否则写入文件开始处
        FileWriter fileWriter = new FileWriter(file,true);
        int i=0;
        for (String list:lists){
            fileWriter.write("\n" + list);
            i++;
        }
        fileWriter.flush();
        fileWriter.close();
        return i;
    }

    public static void main(String[] args) {
        try {
            //通过绝对路径获取文件
            File file = new File("F:/Web/IP.conf");
            //spring boot中文件直接放在resources目录下
            //("classpath:du.txt");

            if (true){
                String s1  = Test.readTxt(file);
                String[] split = s1.split("\\|");
                int i = 0;
                for (String s:split){
                    System.out.println(s);
                    i++;
                }
                System.out.println(i);
            }else {
                List lists = new ArrayList();
                lists.add("127.0.0.1");
                Integer s2 = Test.writeTxt(file,lists);
                System.out.println(s2);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

 

来源：CSDN

作者：我是沐沫

链接：https://blog.csdn.net/qq_41920732/article/details/103780115