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Java > Open Source Codes > com > caucho > quercus > program > TryStatement


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  *
23  * Free Software Foundation, Inc.
24  * 59 Temple Place, Suite 330
25  * Boston, MA 02111-1307 USA
26  *
27  * @author Scott Ferguson
28  */
29
30 package com.caucho.quercus.program;
31
32 import com.caucho.quercus.Location;
33 import com.caucho.quercus.env.Env;
34 import com.caucho.quercus.env.NullValue;
35 import com.caucho.quercus.env.QuercusLanguageException;
36 import com.caucho.quercus.env.Value;
37 import com.caucho.quercus.expr.AbstractVarExpr;
38
39 import java.util.ArrayList JavaDoc;
40
41 /**
42  * Represents sequence of statements.
43  */
44 public class TryStatement extends Statement {
45   protected final Statement _block;
46   protected final ArrayList JavaDoc<Catch> _catchList = new ArrayList JavaDoc<Catch>();
47
48   public TryStatement(Location location, Statement block)
49   {
50     super(location);
51
52     _block = block;
53   }
54
55   public void addCatch(String JavaDoc id, AbstractVarExpr lhs, Statement block)
56   {
57     _catchList.add(new Catch(id, lhs, block));
58   }
59
60   public Value execute(Env env)
61   {
62     try {
63       return _block.execute(env);
64     } catch (QuercusLanguageException e) {
65       Value value = e.getValue();
66
67       for (int i = 0; i < _catchList.size(); i++) {
68     Catch item = _catchList.get(i);
69
70     if (value != null && value.isA(item.getId()) ||
71         value == null && item.getId().equals("Exception")) {
72       if (value != null)
73         item.getExpr().evalAssign(env, value);
74       else
75         item.getExpr().evalAssign(env, NullValue.NULL);
76       
77       return item.getBlock().execute(env);
78     }
79       }
80
81       throw e;
82     }
83   }
84
85   public static class Catch {
86     private final String JavaDoc _id;
87     private final AbstractVarExpr _lhs;
88     private final Statement _block;
89
90     Catch(String JavaDoc id, AbstractVarExpr lhs, Statement block)
91     {
92       _id = id;
93       _lhs = lhs;
94       _block = block;
95
96       if (id == null)
97     throw new NullPointerException JavaDoc();
98     }
99
100     public String JavaDoc getId()
101     {
102       return _id;
103     }
104
105     public AbstractVarExpr getExpr()
106     {
107       return _lhs;
108     }
109
110     public Statement getBlock()
111     {
112       return _block;
113     }
114   }
115 }
116
117
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