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 }
