文件命名

最新推荐文章于 2024-10-31 23:58:35 发布

原创最新推荐文章于 2024-10-31 23:58:35 发布 · 686 阅读

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CC 4.0 BY-SA版权

文章标签：

#string #file #null #thread #class

本文介绍了一个自定义的日志滚动机制实现，该机制能够根据文件大小进行自动滚动，并支持多线程安全写入，同时提供了文件备份的功能。

package io;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
*
* @author chunhuif 2008-7-3
* @version 1.0.0
*/
public class MyLog4j {
private static String fileName="mylog.txt"; //文件路径
private static String maxFileSize = "10k"; //单个文件大小的最大

值可以为 6M 、10G 、3m等等字符格式
    private static String maxBackupIndex ="10"; //最多备份文件数

    private int maxIndex;
    private long maxSize;        //文件最大值
    private BufferedWriter bw;
    private long currentSize=0; //byte
    private File myFile;
    public MyLog4j(){
        super();
        init();
    }
    private void init(){
        myFile = new File(fileName);
        try {
            rollingFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        currentSize=myFile.length();
        maxIndex=Integer.valueOf(maxBackupIndex.trim());
        if (maxFileSize.contains("k")) {
            maxSize = Long.valueOf(maxFileSize.replace("k", "").trim())

* 1024;
} else if (maxFileSize.contains("K")) {
maxSize = Long.valueOf(maxFileSize.replace("K", "").trim())

* 1024;
} else if (maxFileSize.contains("m")) {
maxSize = Long.valueOf(maxFileSize.replace("m", "").trim())

* 1024 * 1024;
} else if (maxFileSize.contains("M")) {
maxSize = Long.valueOf(maxFileSize.replace("M", "").trim())

* 1024 * 1024;
} else if (maxFileSize.contains("G")) {
maxSize = Long.valueOf(maxFileSize.replace("G", "").trim())

* 1024 * 1024 * 1024;
} else if (maxFileSize.contains("g")) {
maxSize = Long.valueOf(maxFileSize.replace("g", "").trim())

* 1024 * 1024 * 1024;
} else if (maxFileSize.contains("T")) {
maxSize = Long.valueOf(maxFileSize.replace("T", "").trim())

* 1024 * 1024 * 1024 * 1024;
} else if (maxFileSize.contains("t")) {
maxSize = Long.valueOf(maxFileSize.replace("t", "").trim())

* 1024 * 1024 * 1024 * 1024;
        }
    }
     private synchronized void rollingFile() throws IOException{
        File f = new File(fileName);
        if(f.exists()){
            rolling(f);
        }
        f.createNewFile();
        bw = new BufferedWriter(new FileWriter(f,true));
    }
    /**
     * 重命名，内部调用例如将mylog.txt 命名为mylog1.txt mylog1.txt 命

名为mylog2.txt
     * @param ff
     */
     private void rolling(File ff){
        if(bw!=null)
            try {
                bw.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        String fn = ff.getName();
        String preFileName=null;
        String tailFileName=null;
        int fileNum = 1;
        if(fileName.contains(".")){
            int index = fileName.lastIndexOf(".");
            preFileName=fileName.substring(0,index);
            String str=fn.substring(preFileName.length(),fn.indexOf

("."));
            if(str!=null&&!str.equals("")){
                fileNum = Integer.valueOf(str)+1;
            }
            tailFileName=fileName.substring(index);
        }else {
            preFileName=fileName;
            fileNum = Integer.valueOf(fn.substring(preFileName.length

()));
            tailFileName="";
        }
        if(fileNum<=maxIndex){
            File nextFile=new File(preFileName+fileNum+tailFileName);
            if(nextFile.exists()){
                rolling(nextFile);
            }
            ff.renameTo(nextFile);
        }else{
            ff.delete();
        }
    }
    /**
     * 将信息写入log中
     * @param message
     */
    public synchronized void write(String message){
        if(currentSize+message.getBytes().length>maxSize){
            try {
                 rollingFile();
                 currentSize=0;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {
            bw.write(message);
            bw.flush();
            currentSize+=message.getBytes().length;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    /**
     * 将信息写入log中
     * @param message
     */
    public synchronized void writeLine(String message){
        write(message+"/n");
    }
    /**
     * 将文件 file 中的内容写入log中
     * @param
     */
    public synchronized void write(File file){
        if(!file.exists()){
            System.out.println("/""+file.getName()+"/" not exist!");
        }
        BufferedReader br=null;
        try {
             br= new BufferedReader(new FileReader(file));
            String message=null;
            while((message=br.readLine())!=null)
            write(message+"/n");
        } catch (IOException e1) {
            e1.printStackTrace();
        }finally{
            if(br!=null){
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    public static void main(String[] args) {
        final MyLog4j log = new MyLog4j();

        for(int l=0;l<50;l++){
            Thread t = new Thread(){
                public void run(){
                    for(int i=0;i<10;i++){
                        log.write(Thread.currentThread().getName()+"

"+i+"/n");
                    }
                }
            };
            t.setName("Thread_"+l);
            t.start();
        }

        for(int i=0;i<10;i++){
            MyLog4j log1 = new MyLog4j();
            log1.write(Thread.currentThread().getName()+" = "+i+"/n");
        }
    }

}