archivereader.html

用JAVA编写的,在做实验的时候留下来的,本来想删的,但是传上来,大家分享吧

<a name="356" href="#356">356</a>         <strong>return</strong> <strong>new</strong> ArchiveRecordIterator();
<a name="357" href="#357">357</a>     }
<a name="358" href="#358">358</a> 
<a name="359" href="#359">359</a> 	<strong>protected</strong> <strong>void</strong> setCompressed(<strong>boolean</strong> compressed) {
<a name="360" href="#360">360</a> 		<strong>this</strong>.compressed = compressed;
<a name="361" href="#361">361</a> 	}
<a name="362" href="#362">362</a> 
<a name="363" href="#363">363</a>     <em>/**<em>*</em></em>
<a name="364" href="#364">364</a> <em>     * @return The current ARC record or null if none.</em>
<a name="365" href="#365">365</a> <em>     * After construction has the arcfile header record.</em>
<a name="366" href="#366">366</a> <em>     * @see #get()</em>
<a name="367" href="#367">367</a> <em>     */</em>
<a name="368" href="#368">368</a> 	<strong>protected</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> getCurrentRecord() {
<a name="369" href="#369">369</a> 		<strong>return</strong> <strong>this</strong>.currentRecord;
<a name="370" href="#370">370</a> 	}
<a name="371" href="#371">371</a> 
<a name="372" href="#372">372</a> 	<strong>protected</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> currentRecord(<strong>final</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> currentRecord) {
<a name="373" href="#373">373</a> 		<strong>this</strong>.currentRecord = currentRecord;
<a name="374" href="#374">374</a>         <strong>return</strong> currentRecord;
<a name="375" href="#375">375</a> 	}
<a name="376" href="#376">376</a> 
<a name="377" href="#377">377</a> 	<strong>protected</strong> InputStream getIn() {
<a name="378" href="#378">378</a> 		<strong>return</strong> in;
<a name="379" href="#379">379</a> 	}
<a name="380" href="#380">380</a> 
<a name="381" href="#381">381</a> 	<strong>protected</strong> <strong>void</strong> setIn(InputStream in) {
<a name="382" href="#382">382</a> 		<strong>this</strong>.in = in;
<a name="383" href="#383">383</a> 	}
<a name="384" href="#384">384</a> 
<a name="385" href="#385">385</a> 	<strong>protected</strong> <strong>void</strong> setVersion(String version) {
<a name="386" href="#386">386</a> 		<strong>this</strong>.version = version;
<a name="387" href="#387">387</a> 	}
<a name="388" href="#388">388</a> 
<a name="389" href="#389">389</a> 	<strong>public</strong> String getReaderIdentifier() {
<a name="390" href="#390">390</a> 		<strong>return</strong> <strong>this</strong>.identifier;
<a name="391" href="#391">391</a> 	}
<a name="392" href="#392">392</a> 
<a name="393" href="#393">393</a> 	<strong>protected</strong> <strong>void</strong> setReaderIdentifier(<strong>final</strong> String i) {
<a name="394" href="#394">394</a> 		<strong>this</strong>.identifier = i;
<a name="395" href="#395">395</a> 	}
<a name="396" href="#396">396</a> 	
<a name="397" href="#397">397</a>     <em>/**<em>*</em></em>
<a name="398" href="#398">398</a> <em>     * Log on stderr.</em>
<a name="399" href="#399">399</a> <em>     * Logging should go via the logging system.  This method</em>
<a name="400" href="#400">400</a> <em>     * bypasses the logging system going direct to stderr.</em>
<a name="401" href="#401">401</a> <em>     * Should not generally be used.  Its used for rare messages</em>
<a name="402" href="#402">402</a> <em>     * that come of cmdline usage of ARCReader ERRORs and WARNINGs.</em>
<a name="403" href="#403">403</a> <em>     * Override if using ARCReader in a context where no stderr or</em>
<a name="404" href="#404">404</a> <em>     * where you'd like to redirect stderr to other than System.err.</em>
<a name="405" href="#405">405</a> <em>     * @param level Level to log message at.</em>
<a name="406" href="#406">406</a> <em>     * @param message Message to log.</em>
<a name="407" href="#407">407</a> <em>     */</em>
<a name="408" href="#408">408</a>     <strong>public</strong> <strong>void</strong> logStdErr(Level level, String message) {
<a name="409" href="#409">409</a>         System.err.println(level.toString() + <span class="string">" "</span> + message);
<a name="410" href="#410">410</a>     }
<a name="411" href="#411">411</a>     
<a name="412" href="#412">412</a>     <em>/**<em>*</em></em>
<a name="413" href="#413">413</a> <em>     * Class that adds PositionableStream methods to a BufferedInputStream.</em>
<a name="414" href="#414">414</a> <em>     */</em>
<a name="415" href="#415">415</a>     <strong>protected</strong> <strong>class</strong> RepositionableBufferedInputStream
<a name="416" href="#416">416</a>     <strong>extends</strong> BufferedInputStream
<a name="417" href="#417">417</a>     		implements RepositionableStream {
<a name="418" href="#418">418</a> 
<a name="419" href="#419">419</a>         <strong>public</strong> RepositionableBufferedInputStream(InputStream is)
<a name="420" href="#420">420</a>         		throws IOException {
<a name="421" href="#421">421</a>             <strong>super</strong>(is);
<a name="422" href="#422">422</a>             doStreamCheck();
<a name="423" href="#423">423</a>         }
<a name="424" href="#424">424</a> 
<a name="425" href="#425">425</a>         <strong>public</strong> RepositionableBufferedInputStream(InputStream is, <strong>int</strong> size)
<a name="426" href="#426">426</a>         		throws IOException {
<a name="427" href="#427">427</a>             <strong>super</strong>(is, size);
<a name="428" href="#428">428</a>             doStreamCheck();
<a name="429" href="#429">429</a>         }
<a name="430" href="#430">430</a>         
<a name="431" href="#431">431</a>         <strong>private</strong> <strong>void</strong> doStreamCheck() throws IOException {
<a name="432" href="#432">432</a>             <strong>if</strong> (!(<strong>this</strong>.in instanceof RepositionableStream)) {
<a name="433" href="#433">433</a>                 <strong>throw</strong> <strong>new</strong> IOException(
<a name="434" href="#434">434</a>                     <span class="string">"Passed stream must implement PositionableStream"</span>);
<a name="435" href="#435">435</a>             }
<a name="436" href="#436">436</a>         }
<a name="437" href="#437">437</a> 
<a name="438" href="#438">438</a>         <strong>public</strong> <strong>long</strong> position() throws IOException {
<a name="439" href="#439">439</a>             <em class="comment">// Current position is the underlying files position</em>
<a name="440" href="#440">440</a>             <em class="comment">// minus the amount thats in the buffer yet to be read.</em>
<a name="441" href="#441">441</a>             <strong>return</strong> ((RepositionableStream)<strong>this</strong>.in).position() -
<a name="442" href="#442">442</a>             	(<strong>this</strong>.count - <strong>this</strong>.pos);
<a name="443" href="#443">443</a>         }
<a name="444" href="#444">444</a> 
<a name="445" href="#445">445</a>         <strong>public</strong> <strong>void</strong> position(<strong>long</strong> position) throws IOException {
<a name="446" href="#446">446</a>             <em class="comment">// Force refill of buffer whenever there's been a seek.</em>
<a name="447" href="#447">447</a>             <strong>this</strong>.pos = 0;
<a name="448" href="#448">448</a>             <strong>this</strong>.count = 0;
<a name="449" href="#449">449</a>             ((RepositionableStream)<strong>this</strong>.in).position(position);
<a name="450" href="#450">450</a>         }
<a name="451" href="#451">451</a>     }
<a name="452" href="#452">452</a>     
<a name="453" href="#453">453</a>     <em>/**<em>*</em></em>
<a name="454" href="#454">454</a> <em>     * Inner ArchiveRecord Iterator class.</em>
<a name="455" href="#455">455</a> <em>     * Throws RuntimeExceptions in {@link #hasNext()} and {@link #next()} if</em>
<a name="456" href="#456">456</a> <em>     * trouble pulling record from underlying stream.</em>
<a name="457" href="#457">457</a> <em>     * @author stack</em>
<a name="458" href="#458">458</a> <em>     */</em>
<a name="459" href="#459">459</a>     <strong>protected</strong> <strong>class</strong> ArchiveRecordIterator implements Iterator&lt;ArchiveRecord> {
<a name="460" href="#460">460</a>         <em>/**<em>*</em></em>
<a name="461" href="#461">461</a> <em>         * @return True if we have more records to read.</em>
<a name="462" href="#462">462</a> <em>         * @exception RuntimeException Can throw an IOException wrapped in a</em>
<a name="463" href="#463">463</a> <em>         * RuntimeException if a problem reading underlying stream (Corrupted</em>
<a name="464" href="#464">464</a> <em>         * gzip, etc.).</em>
<a name="465" href="#465">465</a> <em>         */</em>
<a name="466" href="#466">466</a>         <strong>public</strong> <strong>boolean</strong> hasNext() {
<a name="467" href="#467">467</a>             <em class="comment">// Call close on any extant record.  This will scoot us past</em>
<a name="468" href="#468">468</a>             <em class="comment">// any content not yet read.</em>
<a name="469" href="#469">469</a>             <strong>try</strong> {
<a name="470" href="#470">470</a>                 cleanupCurrentRecord();
<a name="471" href="#471">471</a>             } <strong>catch</strong> (IOException e) {
<a name="472" href="#472">472</a>                 <strong>throw</strong> <strong>new</strong> RuntimeException(e);
<a name="473" href="#473">473</a>             }
<a name="474" href="#474">474</a>             <strong>return</strong> innerHasNext();
<a name="475" href="#475">475</a>         }
<a name="476" href="#476">476</a>         
<a name="477" href="#477">477</a>         <strong>protected</strong> <strong>boolean</strong> innerHasNext() {
<a name="478" href="#478">478</a>             <strong>long</strong> offset = -1;
<a name="479" href="#479">479</a>             <strong>try</strong> {
<a name="480" href="#480">480</a>                 offset = ((RepositionableStream)getInputStream()).position();
<a name="481" href="#481">481</a>                 <strong>return</strong> getInputStream().available() > 0;
<a name="482" href="#482">482</a>             } <strong>catch</strong> (IOException e) {
<a name="483" href="#483">483</a>                 <strong>throw</strong> <strong>new</strong> RuntimeException(<span class="string">"Offset "</span> + offset, e);
<a name="484" href="#484">484</a>             }
<a name="485" href="#485">485</a>         }
<a name="486" href="#486">486</a> 
<a name="487" href="#487">487</a>         <em>/**<em>*</em></em>
<a name="488" href="#488">488</a> <em>         * Tries to move to next record if we get</em>
<a name="489" href="#489">489</a> <em>         * {@link RecoverableIOException}. If not &lt;code>strict&lt;/code></em>
<a name="490" href="#490">490</a> <em>         * tries to move to next record if we get an</em>
<a name="491" href="#491">491</a> <em>         * {@link IOException}.</em>
<a name="492" href="#492">492</a> <em>         * @return Next object.</em>
<a name="493" href="#493">493</a> <em>         * @exception RuntimeException Throws a runtime exception,</em>
<a name="494" href="#494">494</a> <em>         * usually a wrapping of an IOException, if trouble getting</em>
<a name="495" href="#495">495</a> <em>         * a record (Throws exception rather than return null).</em>
<a name="496" href="#496">496</a> <em>         */</em>
<a name="497" href="#497">497</a>         <strong>public</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> next() {
<a name="498" href="#498">498</a>             <strong>long</strong> offset = -1;
<a name="499" href="#499">499</a>             <strong>try</strong> {
<a name="500" href="#500">500</a>                 offset = ((RepositionableStream)getInputStream()).position();
<a name="501" href="#501">501</a>                 <strong>return</strong> exceptionNext();
<a name="502" href="#502">502</a>             } <strong>catch</strong> (IOException e) {
<a name="503" href="#503">503</a>                 <strong>if</strong> (!isStrict()) {
<a name="504" href="#504">504</a>                     <em class="comment">// Retry once.</em>
<a name="505" href="#505">505</a>                     <strong>try</strong> {
<a name="506" href="#506">506</a>                         <strong>if</strong> (hasNext()) {
<a name="507" href="#507">507</a>                             getLogger().warning(<span class="string">"Retrying (Current offset "</span> +
<a name="508" href="#508">508</a>                                 offset + <span class="string">"): "</span> +  e.getMessage());
<a name="509" href="#509">509</a>                             <strong>return</strong> exceptionNext();
<a name="510" href="#510">510</a>                         }
<a name="511" href="#511">511</a>                         <em class="comment">// There is no next and we don't have a record</em>
<a name="512" href="#512">512</a>                         <em class="comment">// to return.  Throw the recoverable.</em>
<a name="513" href="#513">513</a>                         <strong>throw</strong> <strong>new</strong> RuntimeException(<span class="string">"Retried but "</span> +
<a name="514" href="#514">514</a>                             <span class="string">"no next record (Offset "</span> + offset + <span class="string">")"</span>,
<a name="515" href="#515">515</a>                             e);
<a name="516" href="#516">516</a>                     } <strong>catch</strong> (IOException e1) {
<a name="517" href="#517">517</a>                         <strong>throw</strong> <strong>new</strong> RuntimeException(<span class="string">"After retry (Offset "</span> +
<a name="518" href="#518">518</a>                                 offset + <span class="string">")"</span>, e1);
<a name="519" href="#519">519</a>                     }
<a name="520" href="#520">520</a>                 }
<a name="521" href="#521">521</a>                 <strong>throw</strong> <strong>new</strong> RuntimeException(<span class="string">"(Offset "</span> + offset + <span class="string">")"</span>, e);
<a name="522" href="#522">522</a>             }
<a name="523" href="#523">523</a>         }
<a name="524" href="#524">524</a>         
<a name="525" href="#525">525</a>         <em>/**<em>*</em></em>
<a name="526" href="#526">526</a> <em>         * A next that throws exceptions and has handling of</em>
<a name="527" href="#527">527</a> <em>         * recoverable exceptions moving us to next record. Can call</em>
<a name="528" href="#528">528</a> <em>         * hasNext which itself may throw exceptions.</em>
<a name="529" href="#529">529</a> <em>         * @return Next record.</em>
<a name="530" href="#530">530</a> <em>         * @throws IOException</em>
<a name="531" href="#531">531</a> <em>         * @throws RuntimeException Thrown when we've reached maximum</em>
<a name="532" href="#532">532</a> <em>         * retries.</em>
<a name="533" href="#533">533</a> <em>         */</em>
<a name="534" href="#534">534</a>         <strong>protected</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> exceptionNext()
<a name="535" href="#535">535</a>         throws IOException, RuntimeException {
<a name="536" href="#536">536</a>             <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> result = <strong>null</strong>;
<a name="537" href="#537">537</a>             IOException ioe = <strong>null</strong>;