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1
10
11 package org.mmbase.bridge.jsp.taglib.util;
12
13 import javax.servlet.jsp.PageContext  ;
14 import java.util.*;
15 import org.mmbase.util.Casting;
16 import org.mmbase.util.transformers.CharTransformer;
17 import org.mmbase.bridge.jsp.taglib.ContentTag;
18 import org.mmbase.bridge.jsp.taglib.WriterHelper;
19
20 import org.mmbase.util.logging.Logger;
21 import org.mmbase.util.logging.Logging;
22
23
31
32 public class PageContextBacking extends AbstractMap implements Backing {
33
34 private static final Logger log = Logging.getLoggerInstance(PageContextBacking.class);
35
36 private static final int SCOPE = PageContext.PAGE_SCOPE;
37
38 private final PageContext pageContext;
39
40 private final Set nulls = new HashSet();
42
43 private final Set jspvars = new HashSet();
44
45 private final Map unwrapped = new HashMap();
46
47 public PageContextBacking(PageContext pc) {
48 pageContext = pc;
49 }
50
51 public void pushPageContext(PageContext pc) {
52
53 }
54
55 public void pullPageContext(PageContext pc) {
56
57 }
58 public PageContext getPageContext() {
59 return pageContext;
60 }
61
62
63 public void setJspVar(PageContext pc, String jspvar, int vartype, Object value) {
64 if (jspvar == null) return;
65 if (value == null) return;
66 jspvars.add(jspvar);
67 if (vartype == WriterHelper.TYPE_STRING) {
69 Object v = Casting.unWrap(value);
71 if (v == null) return;
72 pc.setAttribute(jspvar, v);
73 } else {
74 pc.setAttribute(jspvar, value);
75 }
76
77 }
78
79 public Set entrySet() {
80 return new AbstractSet() {
81 Collection names = unwrapped.keySet();
82 public Iterator iterator() {
83 return new Iterator() {
84 Iterator back = names.iterator();
85 Iterator nul = null;
86 String name;
87 public Object next() {
88 if (nul == null) {
89 name = (String ) back.next();
90 } else {
91 name = (String ) nul.next();
92 }
93 return new Map.Entry() {
94 public Object getKey() {
95 return name;
96 }
97 public Object getValue() {
98 if (nul == null) {
99 return pageContext.findAttribute(name);
100 } else {
101 return null;
102 }
103 }
104 public Object setValue(Object value) {
105 Object was = pageContext.findAttribute(name);
106 if (value != null) {
107 pageContext.setAttribute(name, jspvars.contains(name) ? value : Casting.wrap(value, (CharTransformer) pageContext.findAttribute(ContentTag.ESCAPER_KEY)), SCOPE);
108 } else {
109 pageContext.removeAttribute(name, SCOPE);
110 nulls.add(name);
111 }
112 return was;
113 }
114 };
115 }
116 public boolean hasNext() {
117 if (back.hasNext()) return true;
118 if (nul == null) nul = nulls.iterator();
119 return nul.hasNext();
120 }
121 public void remove() {
122 pageContext.removeAttribute(name, SCOPE);
123 nulls.remove(name);
124 unwrapped.remove(name);
125 }
126 };
127 }
128 public int size() {
129 return names.size();
130 }
131 };
132 }
133
134
135 public Object put(Object key, Object value) {
136 if (value == null) {
137 nulls.add(key);
138 } else {
139 String k = (String ) key;
140 Object v = jspvars.contains(key) ? value : Casting.wrap(value, (CharTransformer) pageContext.findAttribute(ContentTag.ESCAPER_KEY));
141 pageContext.setAttribute(k, v, SCOPE);
142 }
143 return unwrapped.put(key, value);
144 }
145 public Object get(Object key) {
146 return pageContext.findAttribute((String ) key);
147 }
148 public Object getOriginal(Object key) {
149 Object value = unwrapped.get(key);
150 if (value != null) return value;
151 return pageContext.findAttribute((String ) key);
152 }
153 public boolean containsKey(Object key) {
154 return pageContext.findAttribute((String ) key) != null || nulls.contains(key);
155 }
156
157 public boolean containsOwnKey(Object key) {
158 return unwrapped.containsKey(key);
159 }
160
161 void release() {
162 nulls.clear();
163 unwrapped.clear();
164 jspvars.clear();
165 }
166
167 public String toString() {
168 return "PAGECONTEXT BACKING " + super.toString();
169 }
170
171 }
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