Java读取txt文件和覆盖写入txt文件和追加写入txt

Posted 2020-10-07

package thread;

import java.io.*;

public class hh {

    /**
     * 创建文件
     * @param fileName
     * @return
     */
    public static boolean createFile(File fileName)throws Exception{
        try{
            if(!fileName.exists()){
                fileName.createNewFile();
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        return true;
    }


    /**
     *读取TXT内容
     * @param file
     * @return
     */
    public static String readTxtFile(File file){
        String result = "";
        try {
            InputStreamReader reader = new InputStreamReader(new FileInputStream(file),"gbk");
            BufferedReader br = new BufferedReader(reader);
            String s = null;
            while((s=br.readLine())!=null){
                result = result  + s;
                System.out.println(s);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }


    /**
     * 写入TXT，覆盖原内容
     * @param content
     * @param fileName
     * @return
     * @throws Exception
     */
    public static boolean writeTxtFile(String content,File fileName)throws Exception{
        RandomAccessFile mm=null;
        boolean flag=false;
        FileOutputStream fileOutputStream=null;
        try {
            fileOutputStream = new FileOutputStream(fileName);
            fileOutputStream.write(content.getBytes("gbk"));
            fileOutputStream.close();
            flag=true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return flag;
    }


    /**
     * 写入TXT，追加写入
     * @param filePath
     * @param content
     */
    public static void fileChaseFW(String filePath, String content) {
        try {
            //构造函数中的第二个参数true表示以追加形式写文件
            FileWriter fw = new FileWriter(filePath,true);
            fw.write(content);
            fw.close();
        } catch (IOException e) {
            System.out.println("文件写入失败！" + e);
        }
    }



    public static void main(String[] args) throws Exception{
        File file = new File("D:\\123wu吴.txt");
        createFile(file);
        readTxtFile(file);
//        writeTxtFile("我是写入的内容11",file);
        fileChaseFW("D:\\123wu吴.txt","66666666");
    }
}