| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.services.classfile.CONSTANT_Utf8_info |
| 4 | |
| 5 | Copyright 2000, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.services.classfile; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.classfile.VMDescriptor; |
| 24 | import java.io.IOException; |
| 25 | |
| 26 | /** Constant Pool class - pages 92-99 */ |
| 27 | |
| 28 | /** Utf8- page 100 - Section 4.4.7 */ |
| 29 | public final class CONSTANT_Utf8_info extends ConstantPoolEntry { |
| 30 | private final String value; |
| 31 | private int asString; |
| 32 | private int asCode; |
| 33 | |
| 34 | CONSTANT_Utf8_info(String value) { |
| 35 | super(VMDescriptor.CONSTANT_Utf8); |
| 36 | this.value = value; |
| 37 | } |
| 38 | |
| 39 | Object getKey() { |
| 40 | return value; |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | We assume here that the String is ASCII, thus this |
| 45 | might return a size smaller than actual size. |
| 46 | */ |
| 47 | int classFileSize() { |
| 48 | // 1 (tag) + 2 (utf length) + string length |
| 49 | return 1 + 2 + value.length(); |
| 50 | } |
| 51 | |
| 52 | public String toString() { |
| 53 | return value; |
| 54 | } |
| 55 | |
| 56 | // if this returns 0 then the caller must put another CONSTANT_Utf8_info into the |
| 57 | // constant pool with no hash table entry and then call setAlternative() with its index. |
| 58 | int setAsCode() { |
| 59 | if (ClassHolder.isExternalClassName(value)) |
| 60 | { |
| 61 | if (asString == 0) { |
| 62 | // only used as code at the moment |
| 63 | asCode = getIndex(); |
| 64 | } |
| 65 | |
| 66 | return asCode; |
| 67 | } |
| 68 | // no dots in the string so it can be used as a JVM internal string and |
| 69 | // an external string. |
| 70 | return getIndex(); |
| 71 | } |
| 72 | |
| 73 | int setAsString() { |
| 74 | if (ClassHolder.isExternalClassName(value)) |
| 75 | { |
| 76 | |
| 77 | if (asCode == 0) { |
| 78 | // only used as String at the moment |
| 79 | asString = getIndex(); |
| 80 | } |
| 81 | return asString; |
| 82 | } |
| 83 | |
| 84 | // no dots in the string so it can be used as a JVM internal string and |
| 85 | // an external string. |
| 86 | return getIndex(); |
| 87 | } |
| 88 | |
| 89 | void setAlternative(int index) { |
| 90 | |
| 91 | if (asCode == 0) |
| 92 | asCode = index; |
| 93 | else |
| 94 | asString = index; |
| 95 | } |
| 96 | |
| 97 | void put(ClassFormatOutput out) throws IOException { |
| 98 | super.put(out); |
| 99 | |
| 100 | if (getIndex() == asCode) |
| 101 | { |
| 102 | out.writeUTF(ClassHolder.convertToInternalClassName(value)); |
| 103 | } |
| 104 | else |
| 105 | out.writeUTF(value); |
| 106 | } |
| 107 | } |