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JFile |
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1 // joi/7/jfiles/JFile.java
2 //
3 //
4 // Copyright 2003 Bill Campbell and Ethan Bolker
5
6 import java.util.Date;
7 import java.io.File;
8
9 /**
10 * A JFile object models a file in a hierarchical file system.
11 * <p>
12 * Extend this abstract class to create particular kinds of JFiles,
13 * e.g.:<br>
14 * Directory -
15 * a JFile that maintains a list of the files it contains.<br>
16 * TextFile -
17 * a JFile containing text you might want to read.<br>
18 *
19 * @see Directory
20 * @see TextFile
21 *
22 * @version 7
23 */
24
25 public abstract class JFile
26 {
27 /**
28 * The separator used in pathnames.
29 */
30
31 public static final String separator = File.separator;
32
33 private String name; // a JFile knows its name
34 private User owner; // the owner of this file
35 private Date createDate; // when this file was created
36 private Date modDate; // when this file was last modified
37 private Directory parent; // the Directory containing this file
38
39 /**
40 * Construct a new JFile, set owner, parent, creation and
41 * modification dates. Add this to parent (unless this is the
42 * root Directory).
43 *
44 * @param name the name for this file (in its parent directory).
45 * @param creator the owner of this new file.
46 * @param parent the Directory in which this file lives.
47 */
48
49 protected JFile( String name, User creator, Directory parent )
50 {
51 this.name = name;
52 this.owner = creator;
53 this.parent = parent;
54 if (parent != null) {
55 parent.addJFile( name, this );
56 }
57 createDate = modDate = new Date(); // set dates to now
58 }
59
60 /**
61 * The name of the file.
62 *
63 * @return the file's name.
64 */
65
66 public String getName()
67 {
68 return name;
69 }
70
71 /**
72 * The full path to this file.
73 *
74 * @return the path name.
75 */
76
77 public String getPathName()
78 {
79 if (this.isRoot()) {
80 return separator;
81 }
82 if (parent.isRoot()) {
83 return separator + getName();
84 }
85 return parent.getPathName() + separator + getName();
86 }
87
88 /**
89 * The size of the JFile
90 * (as defined by the child class)..
91 *
92 * @return the size.
93 */
94
95 public abstract int getSize();
96
97 /**
98 * Suffix used for printing file names
99 * (as defined by the child class).
100 *
101 * @return the file's suffix.
102 */
103
104 public abstract String getSuffix();
105
106 /**
107 * Set the owner for this file.
108 *
109 * @param owner the new owner.
110 */
111
112 public void setOwner( User owner )
113 {
114 this.owner = owner;
115 }
116
117 /**
118 * The file's owner.
119 *
120 * @return the owner of the file.
121 */
122
123 public User getOwner()
124 {
125 return owner;
126 }
127
128 /**
129 * The date and time of the file's creation.
130 *
131 * @return the file's creation date and time.
132 */
133
134 public String getCreateDate()
135 {
136 return createDate.toString();
137 }
138
139 /**
140 * Set the modification date to "now".
141 */
142
143 protected void setModDate()
144 {
145 modDate = new Date();
146 }
147
148 /**
149 * The date and time of the file's last modification.
150 *
151 * @return the date and time of the file's last modification.
152 */
153
154 public String getModDate()
155 {
156 return modDate.toString();
157 }
158
159 /**
160 * The Directory containing this file.
161 *
162 * @return the parent directory.
163 */
164
165 public Directory getParent()
166 {
167 return parent;
168 }
169
170 /**
171 * A JFile whose parent is null is defined to be the root
172 * (of a tree).
173 *
174 * @return true when this JFile is the root.
175 */
176
177 public boolean isRoot()
178 {
179 return (parent == null);
180 }
181
182 /**
183 * How a JFile represents itself as a String.
184 * That is,
185 * <pre>
186 * owner size modDate name+suffix
187 * </pre>
188 *
189 * @return the String representation.
190 */
191
192 public String toString()
193 {
194 return getOwner() + "\t" +
195 getSize() + "\t" +
196 getModDate() + "\t" +
197 getName() + getSuffix();
198 }
199 }
200
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JFile |
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