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1
16
17 package org.apache.taglibs.standard.lang.jpath.adapter;
18
19 import java.util.ArrayList  ;
20 import java.util.Collection ;
21 import java.util.Iterator ;
22
23 import javax.servlet.jsp.PageContext ;
24
25 import org.apache.taglibs.standard.lang.jpath.expression.EvaluationException;
26 import org.apache.taglibs.standard.lang.jpath.expression.Expression;
27 import org.apache.taglibs.standard.lang.jpath.expression.Predicate;
28
29 public class CollectionAdapter extends JSPAdapter implements JSPList {
30
31 private Expression predicate;
32
33 private Iterator iterator;
34 private int size;
35 private int position;
36 private Object current;
37
38 public Object next() {
39 position++;
40 current = iterator.next();
41 return current;
42 }
43
44 public Object getCurrent() {
45 return current;
46 }
47
48 public boolean hasNext() {
49 return iterator.hasNext();
50 }
51
52 public int getPosition() {
53 return position;
54 }
55
56 public int getLast() {
57 return size;
58 }
59
60 private void setCollection(Collection c) {
61 this.iterator = c.iterator();
62 this.size = c.size();
63 this.position = 0;
64 }
65
66 public boolean applyPredicate(PageContext pageContext, Predicate predicate) throws ConversionException, EvaluationException {
67 boolean oneItem = false;
68 Object result;
69 boolean predicateTrue;
70 if (position != 0) {
71 throw new ConversionException("You cannot apply a predicate to "
72 + "a JSPList that has begun to be iterated");
73 }
74 Collection predicated = new ArrayList ();
75 while (iterator.hasNext()) {
76 this.next();
77 result = predicate.evaluate(pageContext, new JSPListIterationContext(this));
78 if (result instanceof Double ) {
79 oneItem = true;
80 predicateTrue = ((Double )result).doubleValue() == position;
81 } else {
82 oneItem = false;
83 predicateTrue = Convert.toBoolean(result).booleanValue();
84 }
85 if (predicateTrue) {
86 predicated.add(current);
87 }
88 }
89 this.iterator = predicated.iterator();
90 this.size = predicated.size();
91 this.position = 0;
92 return oneItem;
93 }
94
95 public static Object adapt(Object o) {
96 CollectionAdapter adapter = new CollectionAdapter();
97 adapter.setCollection((Collection )o);
98 return adapter;
99 }
100
101 public static Class [] getAdaptedClasses() {
102 Class [] adaptedClasses = {Collection .class};
103 return adaptedClasses;
104 }
105
106 public void remove() {
107 throw new UnsupportedOperationException ();
108 }
109
110
111 }
112 |
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