数据快速查询的新方法

/**//*


 * Main.java


 *


 * Created on 2006年11月20日, 下午4:29


 *


 * To change this template, choose Tools | Template Manager


 * and open the template in the editor.


 */




package chartest;




/** *//**


 *


 * @author longronglin


 */


import java.util.Random;


import java.io.File;


import java.io.FileReader;


import java.io.FileWriter;


import java.io.BufferedReader;


import java.io.IOException;


import java.io.BufferedWriter;


import java.util.Arrays;


import java.util.Map;


import java.util.HashMap;




public class Main




...{


    private static final int Max = 10019;


    


    private static String[] keyWord = new String[Max];


    


    private static long[] keyNum = new long[Max];


    


    private static String charsetName = "gbk";






    /** *//** Creates a new instance of Main */


    public Main()




    ...{


    }






    /** *//**


     * @param args the command line arguments


     */


    


    public static void main(String[] args) 




    ...{




        /** *//** 关键词文件 */


        String keyWordFile = "d:/keyword.txt";


        




        /** *//** 读取关键词 并存入keyWord数组中 */


        readKeyWord(keyWordFile);


        




        /** *//** 关键词文件对应的前8位字节的long型数 */


        String keyNumFile = "d:/keywordNum.txt";


        




        /** *//** 读取对应的数 并存入keyNum数组中 */


        readKeyNum(keyNumFile);






        /** *//** 根据keyWordFile中的关键词算出每个词的前8位字节对应的long数据 并存入keyNumfile文件中 */


        //writeNumFile(keyWordFile,keyNumFile);


        int i = 0;


        




        /** *//** 对字符串进行顺序查找 */


        long startTime = System.currentTimeMillis();


        for(i=0;i<keyWord.length-3;i++)




        ...{




            /** *//** 字符串对应的首次出现的序号 */


            keyWordSearch(keyWord[i]);


            long endTime = System.currentTimeMillis();


            System.out.println(endTime-startTime);


        }




            


        System.out.println("The first end");




        /** *//** 对keyNum数组进行排序从小到大 */


        Arrays.sort(keyNum);


                


        startTime = System.currentTimeMillis();


        


        for(i=0;i<keyWord.length-3;i++)




        ...{


            int len = 0;




            /** *//** 字符串对应的首次出现的序号 */


            try




            ...{


                len = keyWord[i].getBytes(charsetName).length;


            }


            catch(Exception e)




            ...{


                e.getStackTrace();


            }


            


            if(len <= 8)




            ...{


                keyNumSearch(keyWord[i]);


            }


            else




            ...{


                keyWordSearch(keyWord[i]);


            }


            


            long endTime = System.currentTimeMillis();


            System.out.println(endTime-startTime); 


        }


       




        }


     public static void readKeyWord(String fileName)




     ...{


        int i = 0;


        try 




        ...{


            BufferedReader in = new BufferedReader(new FileReader(fileName));       


            String strTemp = null;


            while ((strTemp = in.readLine()) != null) 




            ...{


                keyWord[i]=strTemp;


                i++;


             }


            in.close();


        } 


        catch (IOException e) 




        ...{


            e.getStackTrace();


        }


     }


     


     public static void readKeyNum(String fileName)




     ...{


        int i = 0;


        try 




        ...{


            BufferedReader in = new BufferedReader(new FileReader(fileName));       


            String strTemp = null;


            while ((strTemp = in.readLine()) != null) 




            ...{


                keyNum[i]=Long.parseLong(strTemp);


                i++;


             }


            in.close();


        } 


        catch (IOException e) 




        ...{


            e.getStackTrace();


        }


     }


     


  


     public static final long getLongOfByteArray (byte[] bytes)




    ...{ 


        long result = 0;


        int len =0;


        


        if(bytes.length<8)




        ...{


            len = bytes.length;


        }


        else




        ...{


            len = 8;


        }


        


        for (int i=0; i<len ; i++) 




        ...{ 


            result=result<<8;   


            result=result+(bytes[i]&0xff);


        } 


        


        return result;


    } 




    public static long keyWordSearch(String str)




    ...{       


        int result=0;


        


        for(int i=0; i<keyWord.length; i++)




        ...{


            if(str.equals(keyWord[i]))




            ...{              


                result = i;


                //System.out.println(i);


                return(i);


            }




        }


               


        return -(result+1);


    }


    


    public static long keyNumSearch(String str)




    ...{


        byte[] strByte = null;


        long result = 0;


        


        try




        ...{


            strByte = str.getBytes(charsetName);


        }


        catch(Exception e)




        ...{


           e.getStackTrace();


        }




        long keyWordNum = getLongOfByteArray(strByte);




        long index = Arrays.binarySearch(keyNum,keyWordNum);


                     


        if(index>0)




        ...{


            return index; 


        }


        


        return -(result+1);


    }


    


    public static void writeNumFile(String srcFile,String dstFile)




    ...{


        File SrcFile=new File(srcFile);


        


        if(!SrcFile.exists())




        ...{ 


            System.err.println("Can't Find " + srcFile);


        }




        try 




        ...{


            BufferedReader in = new BufferedReader(new FileReader(SrcFile));


            BufferedWriter out = new BufferedWriter(new FileWriter(dstFile));


            String str = null;




            while ((str = in.readLine()) != null) 




            ...{


                try 




                ...{              


                    out.write(String.valueOf(getLongOfByteArray(str.getBytes(charsetName))));


                    out.newLine();


                }


                catch (IOException e)




                ...{


                }


            }




            in.close();


            out.close();


        } 


        catch (IOException e) 




        ...{


            e.getStackTrace();


        }


    }


    


    


}