[Java] 读取文件MD5

[hongyangqin]

public static String getMd5ByFile(File file) throws FileNotFoundException {  
            String value = null;  
            FileInputStream in = new FileInputStream(file);  
        try {  
            MappedByteBuffer byteBuffer = in.getChannel().map(FileChannel.MapMode.READ_ONLY, 0, file.length());  
            MessageDigest md5 = MessageDigest.getInstance("MD5");  
            md5.update(byteBuffer);  
            BigInteger bi = new BigInteger(1, md5.digest());  
            value = bi.toString(16);  
        } catch (Exception e) {  
            e.printStackTrace();  
        } finally {  
                if(null != in) {  
                    try {  
                    in.close();  
                    byteBuffer = null;
                    System.gc();
                } catch (IOException e) {  
                    e.printStackTrace();  
                }  
            }  
        }  
        return value;  
        }  

参考

Java读取文件MD5的两种方案