Java读写txt文件

• 读文件
• 写文件

读文件

// 读取文件内容  参数要完成路径和文件名 String filePathName="D:/test/tgj/test1.txt";private static List<String> ReadFileCon(String filePathName){    List<String> strList = new ArrayList<>();    BufferedReader reader;    try {        reader = new BufferedReader(new FileReader(filePathName));        String line = reader.readLine();        while (line != null) {            strList.add(line);            line = reader.readLine();// 继续读取下一行        }        reader.close();        return strList;    } catch (ioException e) {        e.printStackTrace();        System.out.println("文件不存在");        return strList;    }}

如果想直接输出，将代码 strList.add(line); 换成 System.out.println(line); 就行。
方法加个返回值，可方便后续对内容的操作
调用

public static void main(String[] args) {    List<String> list = ReadFileCon("F:\\img\\test1_r.txt");    for (String str: list) {        System.out.println(str);        System.out.println("-------------------------");    }}

需要引入Maven包

import org.apache.commons.io.FileUtils;import org.apache.commons.io.LineIterator;private static void readTxtFileByFileUtils(String fileName) {    File file = new File(fileName);    try {        LineIterator lineIterator = FileUtils.lineIterator(file, "UTF-8");        while (lineIterator.hasNext()) {            String line = lineIterator.nextLine();            System.out.println(line);        }    } catch (IOException e) {        logger.error(e.getMessage());    }}

写文件

// 给指定文件写入内容。若没有就创建，但不能创建目录。String filePathName="D:/test/tgj/test2.txt";private static void WriteFileCon(String filePathName, String[] str){    try (FileWriter fw = new FileWriter(filePathName);         BufferedWriter info = new BufferedWriter(fw))    {        for (int i=0; i<str.length; i++) {            info.write(String.fORMat(str[i] + "%n")); // 加个 %n 相当于换行        }    } catch (IOException e) {        e.printStackTrace();        System.out.println("写入失败");    }}

调用

public static void main(String[] args) {    String[] as = {"熊大", "狗二", "张三", "李四", "王五"};    WriteFileCon("F:/img/test2_w.txt", as);}

方法中可以换成传字符串，那整个for循环就能替换成 info.write(str); 调用时就像下面这样

public static void main(String[] args) {    StringBuilder str = new StringBuilder();    String data1 = "0056b587dfb4901371a09a59a05f10c1";    String data2 = "j23434sdfjjur3247834jhk9eqdf574e";    String data3 = "erigueugd23948924njhsjahf958345j";    str.append(data1);    str.append(System.getProperty("line.separator")); // 效果相当于换行    str.append(data2);    str.append(System.getProperty("line.separator"));    str.append(data3);    str.append(System.getProperty("line.separator"));        WriteFileCon("F:/img/test3_w.txt", str.toString());}

来源地址：https://blog.csdn.net/qq_55342245/article/details/130989135