1 import java.io.BufferedReader;
  2 import java.io.FileReader;
  3 import java.io.IOException;
  4 import java.io.PrintWriter;
  5 import java.util.Hashtable;
  6 
  7 /**
  8  * 利用哈希表进行key值比较
  9  * @author taojx
 10  *
 11  */
 12 public class HashTableComparator {
 13     
 14     public static long RSHash(String key){
 15         long HashCode = 0;
 16         int a = 63689;
 17         int b = 378551;
 18         for(int i=0;i<key.length();i++){
 19             HashCode = HashCode*a+key.charAt(i);
 20             a = a*b;
 21         }
 22         return HashCode;
 23     }
 24     
 25     /**
 26      * 判断冗余行（被注释行或空行）
 27      * @param str
 28      * @return
 29      */
 30     public static boolean JudgeRedundancyStr(String str){
 31         str = str.replace(" ", "");
 32         if(str.indexOf("###") != -1 || str.length() == 0)
 33             return true;
 34         else
 35             return false;
 36     }
 37     
 38     /**
 39      * 将文本中的key值全部保存在hashtable中
 40      * @param PathOfText
 41      * @return
 42      * @thkeys IOException
 43      */
 44     public static Hashtable<Long, String> getKeytable(String PathOfText) throws IOException{
 45 
 46         long key;
 47         String str;
 48         String[] substr;
 49         Hashtable<Long, String> keytable = new Hashtable<Long, String>();
 50         FileReader fr = new FileReader(PathOfText);
 51         BufferedReader br = new BufferedReader(fr);
 52         
 53         while((str=br.readLine())!=null){
 54             
 55             if(JudgeRedundancyStr(str))
 56                 continue;
 57             
 58             substr = str.split("=");
 59             key = RSHash(substr[0]);
 60             
 61             while(keytable.get(key) != null && keytable.get(key) != substr[0])        //查看该key值是否已经被占用，若已经被占用，则key++
 62                 {
 63                     key++;
 64                 }
 65             keytable.put(key, substr[0]);
 66         }
 67 
 68         fr.close();
 69         br.close();
 70         return keytable;
 71     }
 72     
 73     /**
 74      * 判断该key值在该哈希表中是否存在
 75      * @param key
 76      * @param Keytable
 77      * @return
 78      */
 79     public static boolean ExistInKeytable(String key, Hashtable<Long, String> Keytable){
 80         long KeyOfKey;
 81         boolean ExistOfKey = false;
 82         boolean ExistOfValue = false;
 83         String value;
 84         
 85         KeyOfKey = RSHash(key);
 86         
 87         while((value = Keytable.get(KeyOfKey)) != null)
 88         {
 89             if(value.equals(key))
 90             {
 91                 ExistOfValue = true;
 92                 break;
 93             }
 94             KeyOfKey++;
 95         }
 96         
 97         if( ExistOfValue == true)
 98             ExistOfKey = true;
 99         
100         return ExistOfKey;
101     }
102     
103     /**
104      * 将text1的内容与哈希表中text2中的内容比较，输出text1中hashtable没有的内容
105      * @param PathOfText1
106      * @param PathOfText2
107      * @param PathOfDiff
108      * @thkeys IOException
109      */
110     public static void TextCompare(String PathOfText1, String PathOfText2, String PathOfDiff) throws IOException{
111 
112         String str;
113         String[] substr;
114         
115         FileReader fr = new FileReader(PathOfText1);
116         BufferedReader br = new BufferedReader(fr);
117         PrintWriter pw = new PrintWriter(PathOfDiff);
118         Hashtable<Long, String> Keytable = new Hashtable<Long, String>();
119         
120         Keytable = getKeytable(PathOfText2);
121         
122         while((str=br.readLine())!=null){
123             
124             if(JudgeRedundancyStr(str))
125                 continue;
126             
127             substr = str.split("=");
128             
129             if(!ExistInKeytable(substr[0], Keytable))
130             {
131                 pw.println(substr[0]);
132                 pw.println();
133             }
134             
135             System.out.println("........Running........");
136         }
137         
138         System.out.println("........Finished........");
139         fr.close();
140         br.close();
141         pw.close();
142     }
143     
144 public static void main(String[] args) throws IOException{
145         
146         String path1 = "D:\\compare\\Language-cn.txt";
147         String path2 = "D:\\compare\\Language-zh_CN.txt";
148         String path3 = "D:\\compare\\resultII\\KeyDiff-cn.txt";
149         String path4 = "D:\\compare\\resultII\\KeyDiff-zh_CN.txt";
150         
151         TextCompare(path1, path2, path3);
152         TextCompare(path2, path1, path4);
153         
154     }
155 }