java儲存過程根據檔案的內容返回一個MD5值

create or replace and compile java source named java_md5 as
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.AccessControlException;

public class Java_MD5
{
  private final static String[] hexDigits = {"0", "1", "2", "3", "4",  
      "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

  /**
   * 根據帶路徑的檔名返回檔案內容的字串
   * @param fileName
   * @return
   */
  /*private static String readFile(String fileName) {
      String s = "";
      StringBuffer sb = new StringBuffer();
      File inFile = new File(fileName);
      BufferedReader in = null;
      try {
        in = new BufferedReader(new InputStreamReader(new FileInputStream(inFile),"EUC_CN"));
      }
      catch (Exception e) {
        e.printStackTrace();
      }
      try {
        while ( (s = in.readLine()) != null) {
             sb.append(s);
        }
        in.close();
      }
      catch (Exception e) {
        e.printStackTrace();
      }
     
      return sb.toString();
    }
  */
 
    private static String readFile(String fileName) {

 File inFile = new File(fileName);

 if(inFile.exists()){//檢查File.txt是否存在
       String s = "";
       StringBuffer sb = new StringBuffer();
       //File inFile = new File(fileName);
       BufferedReader in = null;
       try {
         in = new BufferedReader(new InputStreamReader(new FileInputStream(inFile),"EUC_CN"));
       }
       catch (Exception e) {
         e.printStackTrace();
       }
       try {
         while ( (s = in.readLine()) != null) {
              sb.append(s);
         }
         in.close();
       }
       catch (Exception e) {
         e.printStackTrace();
       }
       return sb.toString();
 }else{
  return "66";
 }
}
  /**  
   * 轉換位元組陣列為十六進位制字串 
   * @param     位元組陣列 
   * @return    十六進位制字串 
   */ 
  private static String byteArrayToHexString(byte[] b){  
      StringBuffer resultSb = new StringBuffer();  
      for (int i = 0; i < b.length; i++){  
          resultSb.append(byteToHexString(b[i]));  
      }  
      return resultSb.toString();  
  }
 
  /** 將一個位元組轉化成十六進位制形式的字串     */ 
  private static String byteToHexString(byte b){  
      int n = b;  
      if (n < 0)  
          n = 256 + n;  
      int d1 = n / 16;  
      int d2 = n % 16;  
      return hexDigits[d1] + hexDigits[d2];  
  }  

  public static String MD5( String FileName )
  {
    try
    {
       String newString=Java_MD5.readFile( FileName );
     
        //建立具有指定演算法名稱的資訊摘要
    MessageDigest md = MessageDigest.getInstance( "MD5" );
    
    //使用指定的位元組陣列對摘要進行最後更新，然後完成摘要計算
    byte[] mymd5 = md.digest(newString.getBytes());
    
    //將得到的位元組陣列變成字串返回
    String resultString = byteArrayToHexString(mymd5);   
    
    return resultString.toUpperCase();
   } catch (NoSuchAlgorithmException e) {
    
    return "0";
   }
   /*    catch(AccessControlException ex){
    return "0";
   }*/
  }
}

create or replace package PK_Check is

    Function Fn_File_MD5( iFileName In Varchar2 ) Return Varchar2;
   
end PK_Check;

create or replace package body PK_Check is

Function Fn_File_MD5( iFileName In Varchar2 ) Return Varchar2 As Language Java Name 'Java_MD5.MD5( java.lang.String ) return java.lang.String';

begin
     Null;
end PK_Check;