|
1 package org.sapia.soto.state;
2
3 import java.util.ArrayList  ;
4 import java.util.HashMap ;
5 import java.util.List ;
6 import java.util.Map ;
7 import java.util.Stack ;
8
9
10
18 public class ContextImpl implements Context {
19 private Map _scopes = new HashMap ();
20 private List _scopeList = new ArrayList ();
21 protected Stack _stack = new Stack ();
22
23 public ContextImpl() {
24 }
25
26
30 public void addScope(String scope, Scope vals) throws IllegalStateException {
31 if (_scopes.get(scope) != null) {
32 throw new IllegalStateException ("Scope already exists: " + scope);
33 }
34
35 _scopes.put(scope, vals);
36 _scopeList.add(vals);
37 }
38
39
46 protected Scope getScope(String name) {
47 return (Scope) _scopes.get(name);
48 }
49
50
53 public Object get(Object key) {
54 Scope scope;
55 Object toReturn = null;
56
57 for (int i = 0; i < _scopeList.size(); i++) {
58 scope = (Scope) _scopeList.get(i);
59
60 if ((toReturn = scope.getVal(key)) != null) {
61 return toReturn;
62 }
63 }
64
65 return toReturn;
66 }
67
68
71 public Object get(Object key, String [] scopes) {
72 Scope scope;
73 Object toReturn = null;
74
75 for (int i = 0; i < scopes.length; i++) {
76 scope = getScope(scopes[i]);
77
78 if ((scope != null) && ((toReturn = scope.getVal(key)) != null)) {
79 return toReturn;
80 }
81 }
82
83 return toReturn;
84 }
85
86
89 public Object get(Object key, String scope) {
90 if ((scope.length() == 1) && (scope.charAt(0) == STACK_SCOPE)) {
91 if (_stack.size() > 0) {
92 return _stack.peek();
93 } else {
94 return null;
95 }
96 }
97
98 Scope sc = getScope(scope);
99
100 if (sc != null) {
101 return sc.getVal(key);
102 }
103
104 return null;
105 }
106
107
110 public Map getScopes() {
111 return _scopes;
112 }
113
114
117 public void push(Object o) {
118 _stack.push(o);
119 }
120
121
124 public Object pop() {
125 return _stack.pop();
126 }
127
128
131 public Object currentObject() throws IllegalStateException {
132 if (_stack.size() == 0) {
133 throw new IllegalStateException ("No object on context stack");
134 }
135
136 return _stack.peek();
137 }
138
139
142 public boolean hasCurrentObject() {
143 return _stack.size() > 0;
144 }
145 }
146 |
Popular Tags |
Java API By Example, From Geeks To Geeks.