文件相关操作——FileUtil

[java]代码库

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * 文件相关操作
 *
 */
public class FileUtil {
	/**
	 * 文件名，不带扩展名
	 * 
	 * @param fileName
	 * @return
	 */
	public static String getFilePrefix(String fileName) {
		int splitIndex = fileName.lastIndexOf(".");
		return fileName.substring(0, splitIndex);
	}

	/**
	 * 文件扩展名
	 * 
	 * @param fileName
	 * @return
	 */
	public static String getFileSuffix(String fileName) {
		int splitIndex = fileName.lastIndexOf(".");
		return fileName.substring(splitIndex + 1);
	}

	/**
	 * 复制文件
	 * 
	 * @param inputFile
	 * @param outputFile
	 * @throws FileNotFoundException
	 */
	public static void copyFile(String inputFile, String outputFile) throws FileNotFoundException {
		File sFile = new File(inputFile);
		File tFile = new File(outputFile);
		FileInputStream fis = new FileInputStream(sFile);
		FileOutputStream fos = new FileOutputStream(tFile);
		int temp = 0;
		try {
			while ((temp = fis.read()) != -1) {
				fos.write(temp);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				fis.close();
				fos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	/**
	 * 创建目录
	 * 
	 * @param dir
	 * @return
	 */
	public static boolean createDir(String dir) {
		try {
			boolean flag = true;
			File file = new File(dir.toString());
			if (!file.exists()) {
				flag = file.mkdir();
			}
			return flag;
		} catch (Exception e) {
			e.printStackTrace();
			return false;
		}

	}

	/**
	 * 删除文件
	 * 
	 * @param strFilePath
	 * @return
	 */
	public static boolean removeFile(String strFilePath) {
		boolean result = true;
		if (strFilePath == null || "".equals(strFilePath)) {
			return result;
		}
		File file = new File(strFilePath);
		if (file.isFile() && file.exists()) {
			result = file.delete();
		}
		return result;
	}

	/**
	 * 从网络Url中下载文件
	 * @param urlStr
	 * @param fileName
	 * @param savePath
	 * @throws IOException
	 */
	public static void  downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{
		URL url = new URL(urlStr);  
		HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
                //设置超时间为3秒
		conn.setConnectTimeout(3*1000);
		//防止屏蔽程序抓取而返回403错误
		conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

		//得到输入流
		InputStream inputStream = conn.getInputStream();  
		//获取自己数组
		byte[] getData = readInputStream(inputStream);    

		//文件保存位置
		File saveDir = new File(savePath);
		if(!saveDir.exists()){
			saveDir.mkdir();
		}
		File file = new File(saveDir+File.separator+fileName);    
		FileOutputStream fos = new FileOutputStream(file);     
		fos.write(getData); 
		if(fos!=null){
			fos.close();  
		}
		if(inputStream!=null){
			inputStream.close();
		}

	}



	/**
	 * 从输入流中获取字节数组
	 * @param inputStream
	 * @return
	 * @throws IOException
	 */
	public static  byte[] readInputStream(InputStream inputStream) throws IOException {  
		byte[] buffer = new byte[1024];  
		int len = 0;  
		ByteArrayOutputStream bos = new ByteArrayOutputStream();  
		while((len = inputStream.read(buffer)) != -1) {  
			bos.write(buffer, 0, len);  
		}  
		bos.close();  
		return bos.toByteArray();  
	}  

	 
}