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22 package org.apache.struts2.util;
23
24 import java.util.ArrayList;
25 import java.util.Iterator;
26 import java.util.List;
27
28 import com.opensymphony.xwork2.Action;
29
30
31 /***
32 * A bean that takes several iterators and outputs them in sequence
33 *
34 * @see org.apache.struts2.components.AppendIterator
35 * @see org.apache.struts2.views.jsp.iterator.AppendIteratorTag
36 */
37 public class AppendIteratorFilter extends IteratorFilterSupport implements Iterator, Action {
38
39 List iterators = new ArrayList();
40
41
42 List sources = new ArrayList();
43
44
45
46 public void setSource(Object anIterator) {
47 sources.add(anIterator);
48 }
49
50
51 public String execute() {
52
53 for (int i = 0; i < sources.size(); i++) {
54 Object source = sources.get(i);
55 iterators.add(getIterator(source));
56 }
57
58 return SUCCESS;
59 }
60
61
62 public boolean hasNext() {
63 if (iterators.size() > 0) {
64 return (((Iterator) iterators.get(0)).hasNext());
65 } else {
66 return false;
67 }
68 }
69
70 public Object next() {
71 try {
72 return ((Iterator) iterators.get(0)).next();
73 } finally {
74 if (iterators.size() > 0) {
75 if (!((Iterator) iterators.get(0)).hasNext()) {
76 iterators.remove(0);
77 }
78 }
79 }
80 }
81
82 public void remove() {
83 throw new UnsupportedOperationException();
84 }
85 }