以 XXXXdigYYMMdd.txt的形式在手机文件目录下新建文件

最新推荐文章于 2023-08-19 14:16:24 发布

原创最新推荐文章于 2023-08-19 14:16:24 发布 · 1k 阅读

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#以日期格式命名并穿件文件 #string

本文介绍了一个Android应用中如何根据当前日期和已存在的文件名来生成新的文件名，通过递增序列号确保每个文件名的唯一性。

XXXX为序列号，可以认为是随着文件递增的int，例如1234com171201的形式，代码如下：

MainActivity中：

package com.example.wupb.testcreatnewfilebytime;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

import java.io.File;

public class MainActivity extends AppCompatActivity {
    private static final String TAG="BBBBB";
    private File dir;
    private File file;
    private String mYYMMDD;
    private String lastFileName;
    File [] fileLists;
    private int sericiousNum;
    private String baseName;
    String basePath;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        scanFile();
    }
    public void initData(){
        baseName = "WuPengBo";
        sericiousNum = 0;
        basePath= getFilesDir().getPath();
        dir =FileUtils.creatDir(basePath + "/abc");
        mYYMMDD=FileUtils.getYYMMDD();
    }
    public void creat(View v){
        scanFile();
        if(fileLists.length==0){
            sericiousNum = 0000;
            Log.i(TAG,"int sericiousNum =="+sericiousNum);
        }else {
            lastFileName = fileLists[fileLists.length-1].getName();
            if(lastFileName.matches("[0-9]{4}WuPengBo[0-9]{6}\\.txt")) {
                sericiousNum = Integer.parseInt(lastFileName.substring(0, 4));
                Log.i(TAG, "sericiousNum ==" + sericiousNum);
            }
        }
        sericiousNum++;
        String finalName = String.format("%04d",sericiousNum) + baseName + mYYMMDD + ".txt";
        Log.i(TAG,"finalName = "+finalName);
        file = FileUtils.createFile(basePath + "/abc/",finalName);
        Log.i(TAG,"file.getName ==" +file.getName());
    }
    public void scanFile( ){
        fileLists= dir.listFiles();
        for (int i = 0; i <fileLists.length ; i++) {
            Log.i(TAG,"fileName is "+fileLists[i].getName().toString());
            lastFileName = fileLists[fileList().length-1].getName();
        }
    }
}

FileUtils:

package com.example.wupb.testcreatnewfilebytime;

import android.util.Log;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import static android.content.ContentValues.TAG;


/**
 * Created by wupb on 2017/12/2.
 */

public class FileUtils {
    public static File creatDir(String path){
        File file = new File(path);
        if(file.exists()){
            return file;
        }
        file.mkdirs();
        return file;
    }

    public static String getYYMMDD(){
        Calendar calendar=Calendar.getInstance();
        SimpleDateFormat s=new SimpleDateFormat("YYMMdd");
        String result = s.format(calendar.getTime());
        Log.e(TAG, "getYYMMDD:"+result);
        return result;
    }

    public static File createFile(String path,String name){
        File file = new File(path+name);
        if(file.exists()){
            return  file;
        }
        try {
            file.createNewFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return file;
    }
}