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55 package org.lateralnz.common.util;
56
57 import java.util.HashMap  ;
58 import java.util.Set ;
59 import java.util.Iterator ;
60 import java.util.regex.Matcher ;
61 import java.util.regex.Pattern ;
62
63
67 public class FilteredIterator implements Iterator {
68
69 private Pattern ipat;
70 private Pattern epat;
71 private Iterator iter;
72
73 private boolean hasNextProcessed = false;
74 private boolean hasNext = false;
75 private Object next = null;
76
77 public FilteredIterator(Set keyset, String incregex, String excregex) {
78 ipat = Pattern.compile(incregex);
79 epat = Pattern.compile(excregex);
80 iter = keyset.iterator();
81 }
82
83 private Object getNext() {
84 String key;
85 while (iter.hasNext()) {
86 key = (String )iter.next();
87 Matcher imat = ipat.matcher(key);
88 Matcher emat = epat.matcher(key);
89 if (imat.matches() && !emat.matches()) {
90 return key;
91 }
92 }
93 return null;
94 }
95
96 public boolean hasNext() {
97 if (!hasNextProcessed) {
98 next = getNext();
99 if (next != null) {
100 hasNext = true;
101 return true;
102 }
103 }
104 return hasNext;
105 }
106
107 public Object next() {
108 hasNext = false;
109 if (next != null) {
110 Object rtn = next;
111 next = null;
112 return rtn;
113 }
114 else {
115 return getNext();
116 }
117 }
118
119 public void remove() {
120 throw new UnsupportedOperationException ();
121 }
122
123 public static final void main(String [] args) throws Exception {
124 HashMap hm = new HashMap ();
125 hm.put("a/test1", "");
126 hm.put("a/hello2", "");
127 hm.put("a/test4", "");
128 hm.put("a/tst5", "");
129 hm.put("b/", "");
130 hm.put("b/test18", "");
131 hm.put("b/test3", "");
132 hm.put("b/e/test19", "");
133 hm.put("c/test2", "");
134 hm.put("c/whattest52", "");
135
136 FilteredIterator fi = new FilteredIterator(hm.keySet(), "b/[^/]*", "b/|");
137 while (fi.hasNext()) {
138 System.out.println(fi.next());
139 }
140 }
141 }
142 |
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