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21 package org.apache.struts2.util;
22
23 import java.util.ArrayList;
24 import java.util.Iterator;
25 import java.util.List;
26
27 import com.opensymphony.xwork2.Action;
28
29
30 /***
31 * A bean that takes several iterators and outputs them in sequence
32 *
33 * @see org.apache.struts2.components.AppendIterator
34 * @see org.apache.struts2.views.jsp.iterator.AppendIteratorTag
35 */
36 public class AppendIteratorFilter extends IteratorFilterSupport implements Iterator, Action {
37
38 List iterators = new ArrayList();
39
40
41 List sources = new ArrayList();
42
43
44
45 public void setSource(Object anIterator) {
46 sources.add(anIterator);
47 }
48
49
50 public String execute() {
51
52 for (int i = 0; i < sources.size(); i++) {
53 Object source = sources.get(i);
54 iterators.add(getIterator(source));
55 }
56
57 return SUCCESS;
58 }
59
60
61 public boolean hasNext() {
62 if (iterators.size() > 0) {
63 return (((Iterator) iterators.get(0)).hasNext());
64 } else {
65 return false;
66 }
67 }
68
69 public Object next() {
70 try {
71 return ((Iterator) iterators.get(0)).next();
72 } finally {
73 if (iterators.size() > 0) {
74 if (!((Iterator) iterators.get(0)).hasNext()) {
75 iterators.remove(0);
76 }
77 }
78 }
79 }
80
81 public void remove() {
82 throw new UnsupportedOperationException();
83 }
84 }