java對文件的處理，遍歷、下載、刪除、移動等

APP上線良好，后台管理網站需要一個記錄每天app運行日志的功能，有專門代碼人員查看日志有哪些崩潰的地方，具體需求如下：

1、將服務器上文件夾里的日志文件顯示到頁面上，點擊下載可通過瀏覽器將日志文件下載至本地進行查看。

注：為了安全考慮，需要減少對真實日志文件的操作，所以另外新建一個文件夾，將日志文件復制到新的文件夾下進行操作。

2、每天凌晨00：01分，將上一天的日志文件，復制到新的文件夾下，並且刪除新文件夾下前6天的日志文件，一般來說，那些日志文件已經查看，沒作用了，為了節省空間（潔癖）。

一、將磁盤的文件顯示到頁面上

/**
     * 運行日志列表
     * 
     * @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";//待修改路徑  日志文件夾路徑
        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() + " [目錄]");
            } 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;//文件名稱   
    private String url;// 請求的路徑  
    private String filePath;//文件將要保存的目錄
    private String method;//方法 post or get
｝

 

 

 

二、將顯示的日志下載到本地

/**
     * 下載日志
     * 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;//待修改路徑  指定日志文件路徑 下載
        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("瀏覽器下載，找不到源文件", log);
        }
    }

三、定時將服務器的日志文件，復制到新的文件夾下，並且刪除6天前的廢棄日志

<!-- 開啟任務注解掃描 -->
      <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: 定時操作運行日志
 */
@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"+"/";//老目標文件夾下所有文件 //待修改路徑  指定日志文件路徑
        String url = "E:/newlog"+"/";
        
        String cal2 = getCalendar(1);
    //    System.out.println("前一天時間："+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)) {//如果文件修改時間為前一天
                    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()) {                  //文件存在時 
                               InputStream inStream = new FileInputStream(oldPath);      //讀入原文件 
                               FileOutputStream fs = new FileOutputStream(newPath); 
                               byte[] buffer = new byte[1444]; 
                               int length;
                               while ( (byteread = inStream.read(buffer)) != -1) { 
                                   bytesum += byteread;            //字節數 文件大小 
                     //              System.out.println(bytesum); 
                                   fs.write(buffer, 0, byteread); 
                               } 
                               inStream.close();
                           } 
                       }  catch (Exception e) { 
                           System.out.println("復制單個文件操作出錯"); 
                           e.printStackTrace(); 
                       } 
                }
            }
        }
        cal2 = getCalendar(6);
        directory =new File(url+"info.log."+cal2);
        if (directory.exists()) {//刪除
            directory.delete();
        }
           
        
    }
    //獲取日期
    public String getCalendar(int num){
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        int day = cal.get(Calendar.DATE);  //當前時間的前一天
        
        cal.set(Calendar.DATE, day-num);
   //     System.out.println(formatter.format(cal.getTime()));
        return formatter.format(cal.getTime());
    }
}