java对文件的处理，遍历、下载、删除、移动等

APP上线良好，后台管理网站需要一个记录每天app运行日志的功能，有专门代码人员查看日志有哪些崩溃的地方，具体需求如下：

1、将服务器上文件夹里的日志文件显示到页面上，点击下载可通过浏览器将日志文件下载至本地进行查看。

注：为了安全考虑，需要减少对真实日志文件的操作，所以另外新建一个文件夹，将日志文件复制到新的文件夹下进行操作。

2、每天凌晨00：01分，将上一天的日志文件，复制到新的文件夹下，并且删除新文件夹下前6天的日志文件，一般来说，那些日志文件已经查看，没作用了，为了节省空间（洁癖）。

一、将磁盘的文件显示到页面上

/**
     * 运行日志列表
     * 
     * @user Anear
     * @time 17:24
     */
    @RequestMapping("/getCatalinaLog")
    public String getCatalinaLog(AppUserLog appUserLog, String pageNo,
            HttpServletRequest request, HttpServletResponse response,ModelMap model) {
        List<LogLife> logNameList = new ArrayList<LogLife>();
        String filePath = "E:/log_file";//待修改路径  日志文件夹路径
        File f = new File(filePath);
        if (!f.exists()) {
            System.out.println(filePath + " not exists");
            return "appUser/catalinaLog";
        }
        
        File fa[] = f.listFiles();
        
        
        /* for (File file : fa) {
            life.setLogName(file.getName());
            logNameList.add(life);
        }*/
        
        for (int i = 0; i < fa.length; i++) {
            LogLife life = new LogLife();
            life.setLogName("");
            File fs = fa[i];
            if (fs.isDirectory()) {
            //    System.out.println(fs.getName() + " [目录]");
            } else {
            //    System.out.println(fs.getName());
                life.setLogName(fs.getName());
                life.setUrl(fs.getName());
                logNameList.add(life);
            }
        }
        PageList<LogLife> lPageList = new PageList<LogLife>();
        lPageList.setRecords(logNameList);

        model.put("logName", logNameList);
        model.put("pageList", lPageList);
        model.put("appUserLog", appUserLog);
        return "appUser/catalinaLog";
    }

public class LogLife {
    private String logName;//文件名称   
    private String url;// 请求的路径  
    private String filePath;//文件将要保存的目录
    private String method;//方法 post or get
｝

 

 

 

二、将显示的日志下载到本地

/**
     * 下载日志
     * https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png
     * @throws IOException 
     * @user Anear
     * @time 17:24
     */
    @RequestMapping("/downloadingLog")
    public void downloadingLog(AppUserLog appUserLog,String fileName_downLoad, String pageNo,
            HttpServletRequest request, HttpServletResponse response,ModelMap model) throws IOException {
        //String apkPath=YmWebAppConfig.getSYSTEM_FILE_SOURSE().concat(YmWebAppConfig.getUpdateAppAndroidDir()).concat("/"+appInfo.getApkName());
        String apkPath = "E:/log_file"+"/"+fileName_downLoad;//待修改路径  指定日志文件路径 下载
        File apk=new File(apkPath);
        if(apk.exists() && apk.isFile()){
            String fileName=apk.getName();
            response.reset();  
            response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");  
            response.addHeader("Content-Length", "" + apk.length());  
            response.setContentType("application/octet-stream;charset=UTF-8");  
            InputStream inputStream=new FileInputStream(apk);
            byte[] b=new byte[inputStream.available()];
            inputStream.read(b);
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());  
            outputStream.write(b);  
            outputStream.flush();  
            outputStream.close();
            inputStream.close();
        }else{
            LogUtil.errorLog("浏览器下载，找不到源文件", log);
        }
    }

三、定时将服务器的日志文件，复制到新的文件夹下，并且删除6天前的废弃日志

<!-- 开启任务注解扫描 -->
      <task:annotation-driven/>
      <bean id="autoTransTask" class="com.***.***.controller.AutoTransImpl"/>
      <task:scheduled-tasks>
          <task:scheduled ref="autoTransTask" method="executeAutoTrans" cron="0 01 00 * * *"/>
      </task:scheduled-tasks>

/**
 * FileName:    AutoTransImpl
 * Author:      Anear
 * Date:        2017/5/7
 * Description: 定时操作运行日志
 */
@Component("AutoTrans")
public class AutoTransImpl implements AutoTrans {

    @Override
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public void executeAutoTrans() {
        File directory = null;
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
        
        Object obj = "E:/oldlog"+"/";//老目标文件夹下所有文件 //待修改路径  指定日志文件路径
        String url = "E:/newlog"+"/";
        
        String cal2 = getCalendar(1);
    //    System.out.println("前一天时间："+cal2);
          
        if (obj instanceof File) {  
            directory = (File) obj;  
        } else {  
            directory = new File(obj.toString());  
        }  
        ArrayList<File> files = new ArrayList<File>();  
        if (directory.isFile()) {  
            files.add(directory);  
        } else if (directory.isDirectory()) {  
            File[] fileArr = directory.listFiles(); 
            for (File file : fileArr) {
                long time = file.lastModified();          
                cal.setTimeInMillis(time);  
                System.out.println(formatter.format(cal.getTime()));
                if (formatter.format(cal.getTime()).equals(cal2)) {//如果文件修改时间为前一天
                    String oldPath = obj.toString()+file.getName(); //"D:/apache-tomcat-7.0.79/logs/localhost_access_log.2017-09-11.txt";
                    String newPath = url+file.getName();
                //    System.out.println("oldPath:"+oldPath+",,,,,newPath:"+newPath);
                    try { 
                           int bytesum = 0; 
                           int byteread = 0; 
                           File oldfile = new File(oldPath); 
                           if (oldfile.exists()) {                  //文件存在时 
                               InputStream inStream = new FileInputStream(oldPath);      //读入原文件 
                               FileOutputStream fs = new FileOutputStream(newPath); 
                               byte[] buffer = new byte[1444]; 
                               int length;
                               while ( (byteread = inStream.read(buffer)) != -1) { 
                                   bytesum += byteread;            //字节数 文件大小 
                     //              System.out.println(bytesum); 
                                   fs.write(buffer, 0, byteread); 
                               } 
                               inStream.close();
                           } 
                       }  catch (Exception e) { 
                           System.out.println("复制单个文件操作出错"); 
                           e.printStackTrace(); 
                       } 
                }
            }
        }
        cal2 = getCalendar(6);
        directory =new File(url+"info.log."+cal2);
        if (directory.exists()) {//删除
            directory.delete();
        }
           
        
    }
    //获取日期
    public String getCalendar(int num){
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        int day = cal.get(Calendar.DATE);  //当前时间的前一天
        
        cal.set(Calendar.DATE, day-num);
   //     System.out.println(formatter.format(cal.getTime()));
        return formatter.format(cal.getTime());
    }
}