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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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25 
26 package java.util.jar;
27 
28 import java.io.FilterInputStream;
29 import java.io.DataOutputStream;
30 import java.io.InputStream;
31 import java.io.OutputStream;
32 import java.io.IOException;
33 import java.util.Map;
34 import java.util.HashMap;
35 import java.util.Iterator;
36 
37 /**
38  * The Manifest class is used to maintain Manifest entry names and their
39  * associated Attributes. There are main Manifest Attributes as well as
40  * per-entry Attributes. For information on the Manifest format, please
41  * see the
42  * <a href="../../../../technotes/guides/jar/jar.html">
43  * Manifest format specification</a>.
44  *
45  * @author  David Connelly
46  * @see     Attributes
47  * @since   1.2
48  */
49 public class Manifest implements Cloneable {
50     // manifest main attributes
51     private Attributes attr = new Attributes();
52 
53     // manifest entries
54     private Map<String, Attributes> entries = new HashMap<>();
55 
56     /**
57      * Constructs a new, empty Manifest.
58      */
Manifest()59     public Manifest() {
60     }
61 
62     /**
63      * Constructs a new Manifest from the specified input stream.
64      *
65      * @param is the input stream containing manifest data
66      * @throws IOException if an I/O error has occurred
67      */
Manifest(InputStream is)68     public Manifest(InputStream is) throws IOException {
69         read(is);
70     }
71 
72     /**
73      * Constructs a new Manifest that is a copy of the specified Manifest.
74      *
75      * @param man the Manifest to copy
76      */
Manifest(Manifest man)77     public Manifest(Manifest man) {
78         attr.putAll(man.getMainAttributes());
79         entries.putAll(man.getEntries());
80     }
81 
82     /**
83      * Returns the main Attributes for the Manifest.
84      * @return the main Attributes for the Manifest
85      */
getMainAttributes()86     public Attributes getMainAttributes() {
87         return attr;
88     }
89 
90     /**
91      * Returns a Map of the entries contained in this Manifest. Each entry
92      * is represented by a String name (key) and associated Attributes (value).
93      * The Map permits the {@code null} key, but no entry with a null key is
94      * created by {@link #read}, nor is such an entry written by using {@link
95      * #write}.
96      *
97      * @return a Map of the entries contained in this Manifest
98      */
getEntries()99     public Map<String,Attributes> getEntries() {
100         return entries;
101     }
102 
103     /**
104      * Returns the Attributes for the specified entry name.
105      * This method is defined as:
106      * <pre>
107      *      return (Attributes)getEntries().get(name)
108      * </pre>
109      * Though {@code null} is a valid {@code name}, when
110      * {@code getAttributes(null)} is invoked on a {@code Manifest}
111      * obtained from a jar file, {@code null} will be returned.  While jar
112      * files themselves do not allow {@code null}-named attributes, it is
113      * possible to invoke {@link #getEntries} on a {@code Manifest}, and
114      * on that result, invoke {@code put} with a null key and an
115      * arbitrary value.  Subsequent invocations of
116      * {@code getAttributes(null)} will return the just-{@code put}
117      * value.
118      * <p>
119      * Note that this method does not return the manifest's main attributes;
120      * see {@link #getMainAttributes}.
121      *
122      * @param name entry name
123      * @return the Attributes for the specified entry name
124      */
getAttributes(String name)125     public Attributes getAttributes(String name) {
126         return getEntries().get(name);
127     }
128 
129     /**
130      * Clears the main Attributes as well as the entries in this Manifest.
131      */
clear()132     public void clear() {
133         attr.clear();
134         entries.clear();
135     }
136 
137     /**
138      * Writes the Manifest to the specified OutputStream.
139      * Attributes.Name.MANIFEST_VERSION must be set in
140      * MainAttributes prior to invoking this method.
141      *
142      * @param out the output stream
143      * @exception IOException if an I/O error has occurred
144      * @see #getMainAttributes
145      */
write(OutputStream out)146     public void write(OutputStream out) throws IOException {
147         DataOutputStream dos = new DataOutputStream(out);
148         // Write out the main attributes for the manifest
149         attr.writeMain(dos);
150         // Now write out the pre-entry attributes
151         Iterator<Map.Entry<String, Attributes>> it = entries.entrySet().iterator();
152         while (it.hasNext()) {
153             Map.Entry<String, Attributes> e = it.next();
154             StringBuffer buffer = new StringBuffer("Name: ");
155             String value = e.getKey();
156             if (value != null) {
157                 byte[] vb = value.getBytes("UTF8");
158                 value = new String(vb, 0, 0, vb.length);
159             }
160             buffer.append(value);
161             buffer.append("\r\n");
162             make72Safe(buffer);
163             dos.writeBytes(buffer.toString());
164             e.getValue().write(dos);
165         }
166         dos.flush();
167     }
168 
169     /**
170      * Adds line breaks to enforce a maximum 72 bytes per line.
171      */
make72Safe(StringBuffer line)172     static void make72Safe(StringBuffer line) {
173         int length = line.length();
174         if (length > 72) {
175             int index = 70;
176             while (index < length - 2) {
177                 line.insert(index, "\r\n ");
178                 index += 72;
179                 length += 3;
180             }
181         }
182         return;
183     }
184 
185     /**
186      * Reads the Manifest from the specified InputStream. The entry
187      * names and attributes read will be merged in with the current
188      * manifest entries.
189      *
190      * @param is the input stream
191      * @exception IOException if an I/O error has occurred
192      */
read(InputStream is)193     public void read(InputStream is) throws IOException {
194         // Buffered input stream for reading manifest data
195         FastInputStream fis = new FastInputStream(is);
196         // Line buffer
197         byte[] lbuf = new byte[512];
198         // Read the main attributes for the manifest
199         attr.read(fis, lbuf);
200         // Total number of entries, attributes read
201         int ecount = 0, acount = 0;
202         // Average size of entry attributes
203         int asize = 2;
204         // Now parse the manifest entries
205         int len;
206         String name = null;
207         boolean skipEmptyLines = true;
208         byte[] lastline = null;
209 
210         while ((len = fis.readLine(lbuf)) != -1) {
211             if (lbuf[--len] != '\n') {
212                 throw new IOException("manifest line too long");
213             }
214             if (len > 0 && lbuf[len-1] == '\r') {
215                 --len;
216             }
217             if (len == 0 && skipEmptyLines) {
218                 continue;
219             }
220             skipEmptyLines = false;
221 
222             if (name == null) {
223                 name = parseName(lbuf, len);
224                 if (name == null) {
225                     throw new IOException("invalid manifest format");
226                 }
227                 if (fis.peek() == ' ') {
228                     // name is wrapped
229                     lastline = new byte[len - 6];
230                     System.arraycopy(lbuf, 6, lastline, 0, len - 6);
231                     continue;
232                 }
233             } else {
234                 // continuation line
235                 byte[] buf = new byte[lastline.length + len - 1];
236                 System.arraycopy(lastline, 0, buf, 0, lastline.length);
237                 System.arraycopy(lbuf, 1, buf, lastline.length, len - 1);
238                 if (fis.peek() == ' ') {
239                     // name is wrapped
240                     lastline = buf;
241                     continue;
242                 }
243                 name = new String(buf, 0, buf.length, "UTF8");
244                 lastline = null;
245             }
246             Attributes attr = getAttributes(name);
247             if (attr == null) {
248                 attr = new Attributes(asize);
249                 entries.put(name, attr);
250             }
251             attr.read(fis, lbuf);
252             ecount++;
253             acount += attr.size();
254             //XXX: Fix for when the average is 0. When it is 0,
255             // you get an Attributes object with an initial
256             // capacity of 0, which tickles a bug in HashMap.
257             asize = Math.max(2, acount / ecount);
258 
259             name = null;
260             skipEmptyLines = true;
261         }
262     }
263 
parseName(byte[] lbuf, int len)264     private String parseName(byte[] lbuf, int len) {
265         if (toLower(lbuf[0]) == 'n' && toLower(lbuf[1]) == 'a' &&
266             toLower(lbuf[2]) == 'm' && toLower(lbuf[3]) == 'e' &&
267             lbuf[4] == ':' && lbuf[5] == ' ') {
268             try {
269                 return new String(lbuf, 6, len - 6, "UTF8");
270             }
271             catch (Exception e) {
272             }
273         }
274         return null;
275     }
276 
toLower(int c)277     private int toLower(int c) {
278         return (c >= 'A' && c <= 'Z') ? 'a' + (c - 'A') : c;
279     }
280 
281     /**
282      * Returns true if the specified Object is also a Manifest and has
283      * the same main Attributes and entries.
284      *
285      * @param o the object to be compared
286      * @return true if the specified Object is also a Manifest and has
287      * the same main Attributes and entries
288      */
equals(Object o)289     public boolean equals(Object o) {
290         if (o instanceof Manifest) {
291             Manifest m = (Manifest)o;
292             return attr.equals(m.getMainAttributes()) &&
293                    entries.equals(m.getEntries());
294         } else {
295             return false;
296         }
297     }
298 
299     /**
300      * Returns the hash code for this Manifest.
301      */
hashCode()302     public int hashCode() {
303         return attr.hashCode() + entries.hashCode();
304     }
305 
306     /**
307      * Returns a shallow copy of this Manifest.  The shallow copy is
308      * implemented as follows:
309      * <pre>
310      *     public Object clone() { return new Manifest(this); }
311      * </pre>
312      * @return a shallow copy of this Manifest
313      */
clone()314     public Object clone() {
315         return new Manifest(this);
316     }
317 
318     /*
319      * A fast buffered input stream for parsing manifest files.
320      */
321     static class FastInputStream extends FilterInputStream {
322         private byte buf[];
323         private int count = 0;
324         private int pos = 0;
325 
FastInputStream(InputStream in)326         FastInputStream(InputStream in) {
327             this(in, 8192);
328         }
329 
FastInputStream(InputStream in, int size)330         FastInputStream(InputStream in, int size) {
331             super(in);
332             buf = new byte[size];
333         }
334 
read()335         public int read() throws IOException {
336             if (pos >= count) {
337                 fill();
338                 if (pos >= count) {
339                     return -1;
340                 }
341             }
342             return Byte.toUnsignedInt(buf[pos++]);
343         }
344 
read(byte[] b, int off, int len)345         public int read(byte[] b, int off, int len) throws IOException {
346             int avail = count - pos;
347             if (avail <= 0) {
348                 if (len >= buf.length) {
349                     return in.read(b, off, len);
350                 }
351                 fill();
352                 avail = count - pos;
353                 if (avail <= 0) {
354                     return -1;
355                 }
356             }
357             if (len > avail) {
358                 len = avail;
359             }
360             System.arraycopy(buf, pos, b, off, len);
361             pos += len;
362             return len;
363         }
364 
365         /*
366          * Reads 'len' bytes from the input stream, or until an end-of-line
367          * is reached. Returns the number of bytes read.
368          */
readLine(byte[] b, int off, int len)369         public int readLine(byte[] b, int off, int len) throws IOException {
370             byte[] tbuf = this.buf;
371             int total = 0;
372             while (total < len) {
373                 int avail = count - pos;
374                 if (avail <= 0) {
375                     fill();
376                     avail = count - pos;
377                     if (avail <= 0) {
378                         return -1;
379                     }
380                 }
381                 int n = len - total;
382                 if (n > avail) {
383                     n = avail;
384                 }
385                 int tpos = pos;
386                 int maxpos = tpos + n;
387                 while (tpos < maxpos && tbuf[tpos++] != '\n') ;
388                 n = tpos - pos;
389                 System.arraycopy(tbuf, pos, b, off, n);
390                 off += n;
391                 total += n;
392                 pos = tpos;
393                 if (tbuf[tpos-1] == '\n') {
394                     break;
395                 }
396             }
397             return total;
398         }
399 
peek()400         public byte peek() throws IOException {
401             if (pos == count)
402                 fill();
403             if (pos == count)
404                 return -1; // nothing left in buffer
405             return buf[pos];
406         }
407 
readLine(byte[] b)408         public int readLine(byte[] b) throws IOException {
409             return readLine(b, 0, b.length);
410         }
411 
skip(long n)412         public long skip(long n) throws IOException {
413             if (n <= 0) {
414                 return 0;
415             }
416             long avail = count - pos;
417             if (avail <= 0) {
418                 return in.skip(n);
419             }
420             if (n > avail) {
421                 n = avail;
422             }
423             pos += n;
424             return n;
425         }
426 
available()427         public int available() throws IOException {
428             return (count - pos) + in.available();
429         }
430 
close()431         public void close() throws IOException {
432             if (in != null) {
433                 in.close();
434                 in = null;
435                 buf = null;
436             }
437         }
438 
fill()439         private void fill() throws IOException {
440             count = pos = 0;
441             int n = in.read(buf, 0, buf.length);
442             if (n > 0) {
443                 count = n;
444             }
445         }
446     }
447 }
448