//package ipstatistic;
import java.io.*;
import java.util.*;
/**
 * 功能：從文件中提取IP地址，并統(tǒng)計(jì)其出現(xiàn)的數(shù)，暫存在Hash表中
 * @author liangwen 2006/8/1
 */

public class FileHandler extends Thread{
  //當(dāng)前正在操作的文件索引
  private int fileIndex=0;
  //文件的總數(shù)
  private int fileNum;
  //記錄當(dāng)前正處理的行號
  private int lineNum=0;
  //獲取選擇的路徑文件
  private File[] choosedFile;
  //創(chuàng)建鏈路和節(jié)點(diǎn)的Hash table
  private static Hashtable ipHashTable;

  public FileHandler(File[] choosedFile){
    //獲取用戶選擇的輸入文件
    this.choosedFile=choosedFile;
    //Hash表初始容量為97649，裝載因子為0.75
    ipHashTable=new Hashtable(97649,(float)0.75);
  }

 /*啟動線程，依次讀取每一個(gè)文件
  */
  public void run(){
    fileIndex = 0;
    fileNum=this.choosedFile.length;
    while (fileIndex < fileNum)
    {
      try {
             lineNum=0;
             StartLoading(); //裝載文件
          }catch (Exception e1)
          {
            int temp=fileIndex+1;
            System.out.println("FileHandler.run(),at fileNum="
                               +temp+",line="+lineNum+e1.toString());
            ReleaseHash();
            stop();
          }
          fileIndex++;
         IPStatisticFrame.inforOutJTA.append("第"+fileIndex
                                               +"個(gè)文件掃描結(jié)束！\n");
    }
  }
  /*依次處理文件中的每一行數(shù)據(jù)
  */
 private void StartLoading() throws Exception
  {
          String bufferStr;
          BufferedReader br = getBufferedReader();

          if (br == null)
          {
             System.out.println("IOHandler.StartLoading():"+
                                "InputStream is null");
             ReleaseHash();
             stop();
          }
          //每次讀取一行數(shù)據(jù)先存入bufferStr中
          while((bufferStr = br.readLine()) != null){
              lineNum++;
              //IP地址最短為7個(gè)字符，如果總長度小于7，說明該行沒有IP地址
              if (bufferStr.length() < 7)
                  continue;
              ParseString(new StringTokenizer(bufferStr));
          }
  }

  /*依次處理一行數(shù)據(jù)中的每一IP地址
  */
 private void ParseString(StringTokenizer tokenizer) throws Exception
  {
    String ipStr;
    String hashKey,hashValue;
    //依次處理每一節(jié)點(diǎn)
    while(tokenizer.hasMoreTokens()) {
           ipStr=tokenizer.nextToken().toString();
           //判斷是否為合法的IP地址
          if(!IsIP(ipStr))
              continue;
          //將節(jié)點(diǎn)存入Hash表
          //value格式：節(jié)點(diǎn)的IP地址
          //key格式：該IP地址出現(xiàn)的次數(shù)
          hashKey=ipStr;
          hashValue=this.GetHashValue(this.ipHashTable,hashKey);
          this.ipHashTable.put(hashKey, hashValue);
          }
    }

 /*判斷給定字符串是否為IPv4地址
  */
 private boolean IsIP(String IPStr){
        int length=IPStr.length();
        //當(dāng)前掃描的字符位置
        int index=0;
        //記錄每個(gè)8位組中字符個(gè)數(shù)，IPv4地址中其最大取值為3
        int inOctetNum=0;
        //記錄IPv4地址中8位組的個(gè)數(shù)，最大取值為4
        int Octets=1;
        //判斷給定字符串是否為IPv4地址
        boolean IsIP = false;

        char temp;
        try {
         while (index < length) {
           temp = IPStr.charAt(index);
           if (! ( (temp >= '0' && temp <= '9') || temp == '.')) {
             IsIP = false;
             break;
           }
           if (temp == '.') {
             inOctetNum = 0;
             Octets++;
           }
           else {
             inOctetNum++;
             if (inOctetNum > 3) {
               IsIP = false;
               break;
             }
           }
           index++;
         }
       }catch (Exception ex) {
          System.out.println("FileHandler.IsIP():"+ex.toString());
         }
     if( index == length  && Octets==4 && inOctetNum <=3)
        IsIP=true;
     return IsIP;
 }

/*獲取對應(yīng)HashKey的HashValue，
 */
 private String GetHashValue(Hashtable inforHashTable, String hashKey){
   String hashValue;
   int num;
   try {
     if(inforHashTable.containsKey(hashKey)){
       //獲取原始值
       hashValue=inforHashTable.get(hashKey).toString();
       num=Integer.parseInt(hashValue);
       //原值加一
       hashValue=Integer.toString(num+1);
       //刪除舊值
       inforHashTable.remove(hashKey);
      }
      else
       //設(shè)置初值
       hashValue="1";
      return hashValue;
   }
   catch (Exception ex) {
       System.out.println("FileHandler.GetHashValue():"+ex.toString());
       return null;
   }
 }

 /*獲取用于讀取文件的流
  */
  private BufferedReader getBufferedReader()
     {
           BufferedReader br = null;
           try {
                 File file;
                 file = choosedFile[fileIndex];
                 if (!file.canRead())
                   System.out.println("FileHandler.getBufferedReader()"+
                             "can't read file");
                 br = new BufferedReader(
                      new InputStreamReader(
                      new FileInputStream(file)));
            }
            catch (FileNotFoundException e1) {
                 System.out.println("FileHandler.getBufferedReader():"
                                    +e1.toString());
                 ReleaseHash();
                 stop();
            }
           return br;
      }

/*獲取路徑IP地址表
 */
 static Hashtable GetIPTable(){
        return ipHashTable;
 }

/*釋放資源
 */
 void ReleaseHash(){
     if(!this.ipHashTable.isEmpty())
       this.ipHashTable.clear();
  }
}