Java文件上传验证

àì夳堔傛蜴生んèń 2022-06-16 09:16 223阅读 0赞

##### **不光能对文件限制，还能对文件真实的类型进行限制，跟Struts2的文件上传差不多。** #####

package lee;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.InputStream;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Map.Entry;
    public class Demo {
        
    	public static void main(String[] args) throws Exception{//D0CF11E0
    		File file = new File("C:\\Users\\whaty-ctj\\Desktop\\11111.zip");
    		if(!(fileLastName(file).equals("doc"))){ // 如果不是指定的后缀名
    			//return;
    		}
    		//System.out.println(getFileByFile(file));
    		System.out.println(file.exists());
    		FileInputStream fis = new FileInputStream(file);
    		FileOutputStream fos = new FileOutputStream("E:\\xx.zip");
    		// FILE_TYPE_MAP.put("doc", "D0CF11E0");
    		int len = 0;
    		byte[] buffer = new byte[1024*1024];
    		while((len = fis.read(buffer))>0){
    			fos.write(buffer,0,len);
    		}
    		
    		fos.flush();
    		fos.close();
    		fis.close();
    	}
    	
    	 public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();
        /**   
         * Created on 2010-7-1    
         * <p>Discription:[getAllFileType,常见文件头信息]</p>   
         * @author:[shixing_11@sina.com]   
         */     
        private static void getAllFileType(){
            FILE_TYPE_MAP.put("jpg", "FFD8FF"); //JPEG (jpg)
            FILE_TYPE_MAP.put("png", "89504E47"); //PNG (png)
            FILE_TYPE_MAP.put("gif", "47494638"); //GIF (gif)
            FILE_TYPE_MAP.put("tif", "49492A00"); //TIFF (tif)
            FILE_TYPE_MAP.put("bmp", "424D"); //Windows Bitmap (bmp)
            FILE_TYPE_MAP.put("dwg", "41433130"); //CAD (dwg)
            FILE_TYPE_MAP.put("html", "68746D6C3E"); //HTML (html)
            FILE_TYPE_MAP.put("rtf", "7B5C727466"); //Rich Text Format (rtf)
            FILE_TYPE_MAP.put("xml", "3C3F786D6C");
            FILE_TYPE_MAP.put("zip", "504B0304");
            FILE_TYPE_MAP.put("rar", "52617221");
            FILE_TYPE_MAP.put("psd", "38425053"); //Photoshop (psd)
            FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A"); //Email [thorough only] (eml)
            FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F"); //Outlook Express (dbx)
            FILE_TYPE_MAP.put("pst", "2142444E"); //Outlook (pst)
            FILE_TYPE_MAP.put("xls", "D0CF11E0"); //MS Word
            FILE_TYPE_MAP.put("doc", "D0CF11E0"); //MS Excel 注意：word 和 excel的文件头一样
            FILE_TYPE_MAP.put("mdb", "5374616E64617264204A"); //MS Access (mdb)
            FILE_TYPE_MAP.put("wpd", "FF575043"); //WordPerfect (wpd)
            FILE_TYPE_MAP.put("eps", "252150532D41646F6265");
            FILE_TYPE_MAP.put("ps", "252150532D41646F6265");
            FILE_TYPE_MAP.put("pdf", "255044462D312E"); //Adobe Acrobat (pdf)
            FILE_TYPE_MAP.put("qdf", "AC9EBD8F"); //Quicken (qdf)
            FILE_TYPE_MAP.put("pwl", "E3828596"); //Windows Password (pwl)
            FILE_TYPE_MAP.put("wav", "57415645"); //Wave (wav)
            FILE_TYPE_MAP.put("avi", "41564920");
            FILE_TYPE_MAP.put("ram", "2E7261FD"); //Real Audio (ram)
            FILE_TYPE_MAP.put("rm", "2E524D46"); //Real Media (rm)
            FILE_TYPE_MAP.put("mpg", "000001BA"); //
            FILE_TYPE_MAP.put("mov", "6D6F6F76"); //Quicktime (mov)
            FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); //Windows Media (asf)
            FILE_TYPE_MAP.put("mid", "4D546864"); //MIDI (mid)
        }
    	
        static{
        	getAllFileType();
        }
    	/**
    	 * 获取文件类型
    	 * 
    	 * @param file
    	 * @return
    	 */
    	public static String getFileByFile(File file){
    		String fileType = null;
    		byte[] b = new byte[20];
    		try{
    			InputStream is = new FileInputStream(file);
    			is.read(b);
    			fileType = getFileTypeByStream(b);
    			is.close();
    		}catch(Exception e){
    			e.printStackTrace(); // 错误信息
    		}
    		return fileType;
    	}
    	
    	/* 由于每一种文件的类型都不一致，所以这个用来判断文件类型。 */
    	private static String getFileTypeByStream(byte[] b) {
    		String filetypeHex = String.valueOf(getFileHexString(b));
    		Iterator<Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();
    		while (entryiterator.hasNext()){
    			Entry<String,String> entry = entryiterator.next();
    			String fileTypeHexValue = entry.getValue(); 
    			System.out.println(fileTypeHexValue + "  ==  " + filetypeHex);
    			if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {
    				return entry.getKey();
    			}
    		}
    		return null;
    	}
    	public final static String getFileHexString(byte[] b) {     
    		StringBuilder stringBuilder = new StringBuilder();     
    		if(b == null || b.length <= 0) {
    			return null;
    		}
    		for (int i = 0; i < b.length; i++) {
    			int v = b[i] & 0xFF;
    			String hv = Integer.toHexString(v);
    			if (hv.length() < 2) {
    				stringBuilder.append(0);
    			}
    			stringBuilder.append(hv);
    		}
    		return stringBuilder.toString();
    	}
    
    	/**
    	 * 获取文件名称的后缀。
    	 * 
    	 * @param file
    	 * @return
    	 */
    	public static String fileLastName(File file){
    		String fileName = file.getName();
    		String result = fileName.substring(fileName.lastIndexOf(".")+1,fileName.length());
    		return result;
    	}
    }