Java 文件操作工具类

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.io.FileUtils;

import com.bcap_systemlib.config.Configuration;

public class FileUtil {
    /**
     * 将多个文件打包到一个zip中
     *
     * @param sourceFolder
     * @param zipFile
     * @return
     * @throws Exception 
     */
    public static boolean zipFile(String sourceFolder, File zipFile) throws Exception{
        boolean isOk = true;
        File f = new File(sourceFolder);
        ZipOutputStream out = null;
        try{
            if(!f.exists()){
                f.mkdirs();
            }
            out = new ZipOutputStream(new FileOutputStream(zipFile));
            zip(out, f, "");
            out.flush();
            FileUtils.deleteDirectory(f);
        } catch (Exception e){
            e.printStackTrace();
            throw new Exception("压缩文件出错！");
        } finally
        {
            if(null != out){
                try{ out.close(); } catch (Exception e){ e.printStackTrace();}
            }
        }
        return isOk;
    }

    /**
     * 递归压缩文件
     * @param out
     * @param f
     * @param base
     * @throws Exception
     */
    private static void zip(ZipOutputStream out, File f, String base) throws Exception {
        if (f.isDirectory()) {
            File[] fl = f.listFiles();
            out.putNextEntry(new ZipEntry(base + "/"));
            base = base.length() == 0 ? "" : base + "/";
            for (int i = 0; i < fl.length; i++) {
                zip(out, fl[i], base + fl[i].getName());
            }
        }else {
            out.putNextEntry(new ZipEntry(base));
            FileInputStream in = new FileInputStream(f);
            int b;
            while ( (b = in.read()) != -1) {
                out.write(b);
            }
            in.close();
        }
    }

    /**
     * 下载单个文件
     *
     * @param file
     * @param request
     * @param response
     * @return
     */
    public static boolean downFile(File file, HttpServletRequest request, HttpServletResponse response) {
        boolean isOk = true;
        OutputStream myout = null;
        FileInputStream fis = null;
        BufferedInputStream buff = null;
        HttpSession session = request.getSession();
        if (session != null) {
            session.setAttribute("state", "");
        }
        try {
            response.setContentType("application/x-msdownload");
            response.setContentLength((int) file.length());
            response.setHeader("content-disposition", "attachment;filename=" + EncodingConvertUtil.utf2iso(file.getName()));
            fis = new FileInputStream(file);
            buff = new BufferedInputStream(fis);
            byte[] b = new byte[1024 * 10];//相当于我们的缓存
            long k = 0;//该值用于计算当前实际下载了多少字节
            //从response对象中得到输出流,准备下载
            myout = response.getOutputStream();
            while (k < file.length()) {
                int j = buff.read(b, 0, b.length);
                k += j;
                //将b中的数据写到客户端的内存
                myout.write(b, 0, j);
            }
            myout.flush();
        } catch (Exception e) {
            e.printStackTrace();
            isOk = false;
        } finally {
            try {
                if (null != myout) {
                    myout.close();
                    myout = null;
                }
                if (null != buff) {
                    buff.close();
                    buff = null;
                }
                if (null != fis) {
                    fis.close();
                    fis = null;
                }
                if(file.exists()){
                    FileUtil.delFile(file);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return isOk;
    }

    /**
     * 删除单个文件
     *
     * @param file
     * @return
     */
    public static boolean delFile(File file) {
        boolean isOk = true;
        try {
            if (file.isFile() && file.exists()) {
                file.delete();
            }
        } catch (Exception e) {
            e.printStackTrace();
            isOk = false;
        } finally {
            // log ...
        }
        return isOk;
    }
    
    public static void downloadFileFromRemote(String remoteFilePath, String localFilePath){
        URL urlfile = null;
        HttpURLConnection httpUrl = null;
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        File f = new File(localFilePath);
        try
        {
            urlfile = new URL(remoteFilePath);
            httpUrl = (HttpURLConnection)urlfile.openConnection();
            httpUrl.connect();
            bis = new BufferedInputStream(httpUrl.getInputStream());
            bos = new BufferedOutputStream(new FileOutputStream(f));
            int len = 2048;
            byte[] b = new byte[len];
            while ((len = bis.read(b)) != -1)
            {
                bos.write(b, 0, len);
            }
            System.out.println("下载成功");
            bos.flush();
            bis.close();
            httpUrl.disconnect();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            try
            {
                bis.close();
                bos.close();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
    }
    
    public static void writeFile(String filePathAndName, String fileContent) {
    	try {
    		File f = new File(filePathAndName);
    		if (!f.exists()) {
    			f.createNewFile();
    		}
    		OutputStreamWriter write = new OutputStreamWriter(new FileOutputStream(f),Configuration.SERVLET_CHARACTER_ENCODING);
    		BufferedWriter writer=new BufferedWriter(write);   
    		writer.write(fileContent);
    		writer.close();
    	} catch (Exception e) {
			System.out.println("写文件内容操作出错");
			e.printStackTrace();
    	}
    }
    
    public static String readFile(String filePathAndName) {
    	String fileContent = "";
    	try {  
    		File f = new File(filePathAndName);
    		if(f.isFile()&&f.exists()){
    			InputStreamReader read = new InputStreamReader(new FileInputStream(f),Configuration.SERVLET_CHARACTER_ENCODING);
    			BufferedReader reader=new BufferedReader(read);
    			String line;
    			while ((line = reader.readLine()) != null) {
    				fileContent += line;
    			}   
    			read.close();
    		}
    	} catch (Exception e) {
    		System.out.println("读取文件内容操作出错");
    		e.printStackTrace();
    	}
    	return fileContent;
    }
    
    public static String getExtName(String filename) {
        int index = filename.lastIndexOf(".");
 
        if (index == -1) {
            return null;
        }
        String result = filename.substring(index);
        return result;
    }
}