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="174" href="#174">174</a>                 ((RepositionableStream)<strong>this</strong>.in).position(0);
<a name="175" href="#175">175</a>             } <strong>catch</strong> (IOException e) {
<a name="176" href="#176">176</a>                 <strong>throw</strong> <strong>new</strong> RuntimeException(e);
<a name="177" href="#177">177</a>             }
<a name="178" href="#178">178</a>        } <strong>else</strong> {
<a name="179" href="#179">179</a>            <strong>throw</strong> <strong>new</strong> IOException(<span class="string">"Stream is not resettable."</span>);
<a name="180" href="#180">180</a>        }
<a name="181" href="#181">181</a>     }
<a name="182" href="#182">182</a>     
<a name="183" href="#183">183</a>     <em>/**<em>*</em></em>
<a name="184" href="#184">184</a> <em>     * Cleanout the current record if there is one.</em>
<a name="185" href="#185">185</a> <em>     * @throws IOException</em>
<a name="186" href="#186">186</a> <em>     */</em>
<a name="187" href="#187">187</a>     <strong>protected</strong> <strong>void</strong> cleanupCurrentRecord() throws IOException {
<a name="188" href="#188">188</a>         <strong>if</strong> (<strong>this</strong>.currentRecord != <strong>null</strong>) {
<a name="189" href="#189">189</a>             <strong>this</strong>.currentRecord.close();
<a name="190" href="#190">190</a>             gotoEOR(<strong>this</strong>.currentRecord);
<a name="191" href="#191">191</a>             <strong>this</strong>.currentRecord = <strong>null</strong>;
<a name="192" href="#192">192</a>         }
<a name="193" href="#193">193</a>     }
<a name="194" href="#194">194</a>     
<a name="195" href="#195">195</a>     <em>/**<em>*</em></em>
<a name="196" href="#196">196</a> <em>     * Return an Archive Record homed on &lt;code>offset&lt;/code> into</em>
<a name="197" href="#197">197</a> <em>     * &lt;code>is&lt;/code>.</em>
<a name="198" href="#198">198</a> <em>     * @param is Stream to read Record from.</em>
<a name="199" href="#199">199</a> <em>     * @param offset Offset to find Record at.</em>
<a name="200" href="#200">200</a> <em>     * @return ArchiveRecord instance.</em>
<a name="201" href="#201">201</a> <em>     * @throws IOException</em>
<a name="202" href="#202">202</a> <em>     */</em>
<a name="203" href="#203">203</a>     <strong>protected</strong> <strong>abstract</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> createArchiveRecord(InputStream is,
<a name="204" href="#204">204</a>     	<strong>long</strong> offset)
<a name="205" href="#205">205</a>     throws IOException;
<a name="206" href="#206">206</a>     
<a name="207" href="#207">207</a>     <em>/**<em>*</em></em>
<a name="208" href="#208">208</a> <em>     * Skip over any trailing new lines at end of the record so we're lined up</em>
<a name="209" href="#209">209</a> <em>     * ready to read the next.</em>
<a name="210" href="#210">210</a> <em>     * @param record</em>
<a name="211" href="#211">211</a> <em>     * @throws IOException</em>
<a name="212" href="#212">212</a> <em>     */</em>
<a name="213" href="#213">213</a>     <strong>protected</strong> <strong>abstract</strong> <strong>void</strong> gotoEOR(<a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> record) throws IOException;
<a name="214" href="#214">214</a>     
<a name="215" href="#215">215</a>     <strong>public</strong> <strong>abstract</strong> String getFileExtension();
<a name="216" href="#216">216</a>     <strong>public</strong> <strong>abstract</strong> String getDotFileExtension();
<a name="217" href="#217">217</a> 
<a name="218" href="#218">218</a>     <em>/**<em>*</em></em>
<a name="219" href="#219">219</a> <em>     * @return Version of this Archive file.</em>
<a name="220" href="#220">220</a> <em>     */</em>
<a name="221" href="#221">221</a>     <strong>public</strong> String getVersion() {
<a name="222" href="#222">222</a>     	<strong>return</strong> <strong>this</strong>.version;
<a name="223" href="#223">223</a>     }
<a name="224" href="#224">224</a> 
<a name="225" href="#225">225</a>     <em>/**<em>*</em></em>
<a name="226" href="#226">226</a> <em>     * Validate the Archive file.</em>
<a name="227" href="#227">227</a> <em>     *</em>
<a name="228" href="#228">228</a> <em>     * This method iterates over the file throwing exception if it fails</em>
<a name="229" href="#229">229</a> <em>     * to successfully parse any record.</em>
<a name="230" href="#230">230</a> <em>     *</em>
<a name="231" href="#231">231</a> <em>     * &lt;p>Assumes the stream is at the start of the file.</em>
<a name="232" href="#232">232</a> <em>     * @return List of all read Archive Headers.</em>
<a name="233" href="#233">233</a> <em>     *</em>
<a name="234" href="#234">234</a> <em>     * @throws IOException</em>
<a name="235" href="#235">235</a> <em>     */</em>
<a name="236" href="#236">236</a>     <strong>public</strong> List validate() throws IOException {
<a name="237" href="#237">237</a>         <strong>return</strong> validate(-1);
<a name="238" href="#238">238</a>     }
<a name="239" href="#239">239</a> 
<a name="240" href="#240">240</a>     <em>/**<em>*</em></em>
<a name="241" href="#241">241</a> <em>     * Validate the Archive file.</em>
<a name="242" href="#242">242</a> <em>     *</em>
<a name="243" href="#243">243</a> <em>     * This method iterates over the file throwing exception if it fails</em>
<a name="244" href="#244">244</a> <em>     * to successfully parse.</em>
<a name="245" href="#245">245</a> <em>     *</em>
<a name="246" href="#246">246</a> <em>     * &lt;p>We start validation from whereever we are in the stream.</em>
<a name="247" href="#247">247</a> <em>     *</em>
<a name="248" href="#248">248</a> <em>     * @param noRecords Number of records expected.  Pass -1 if number is</em>
<a name="249" href="#249">249</a> <em>     * unknown.</em>
<a name="250" href="#250">250</a> <em>     *</em>
<a name="251" href="#251">251</a> <em>     * @return List of all read metadatas. As we validate records, we add</em>
<a name="252" href="#252">252</a> <em>     * a reference to the read metadata.</em>
<a name="253" href="#253">253</a> <em>     *</em>
<a name="254" href="#254">254</a> <em>     * @throws IOException</em>
<a name="255" href="#255">255</a> <em>     */</em>
<a name="256" href="#256">256</a>     <strong>public</strong> List validate(<strong>int</strong> noRecords) throws IOException {
<a name="257" href="#257">257</a>         List&lt;ArchiveRecordHeader> hs = <strong>new</strong> ArrayList&lt;ArchiveRecordHeader>();
<a name="258" href="#258">258</a>         <strong>int</strong> count = 0;
<a name="259" href="#259">259</a>         setStrict(<strong>true</strong>);
<a name="260" href="#260">260</a>         <strong>for</strong> (Iterator&lt;ArchiveRecord> i = iterator(); i.hasNext();) {
<a name="261" href="#261">261</a>             count++;
<a name="262" href="#262">262</a>             <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> r = i.next();
<a name="263" href="#263">263</a>             <strong>if</strong> (r.getHeader().getLength() &lt;= 0
<a name="264" href="#264">264</a>                 &amp;&amp; r.getHeader().getMimetype().
<a name="265" href="#265">265</a>                     equals(MimetypeUtils.NO_TYPE_MIMETYPE)) {
<a name="266" href="#266">266</a>                 <strong>throw</strong> <strong>new</strong> IOException(<span class="string">"ARCRecord content is empty."</span>);
<a name="267" href="#267">267</a>             }
<a name="268" href="#268">268</a>             r.close();
<a name="269" href="#269">269</a>             <em class="comment">// Add reference to metadata into a list of metadatas.</em>
<a name="270" href="#270">270</a>             hs.add(r.getHeader());
<a name="271" href="#271">271</a>         }
<a name="272" href="#272">272</a> 
<a name="273" href="#273">273</a>         <strong>if</strong> (noRecords != -1) {
<a name="274" href="#274">274</a>             <strong>if</strong> (count != noRecords) {
<a name="275" href="#275">275</a>                 <strong>throw</strong> <strong>new</strong> IOException(<span class="string">"Count of records, "</span> +
<a name="276" href="#276">276</a>                     Integer.toString(count) + <span class="string">" is less than expected "</span> +
<a name="277" href="#277">277</a>                     Integer.toString(noRecords));
<a name="278" href="#278">278</a>             }
<a name="279" href="#279">279</a>         }
<a name="280" href="#280">280</a> 
<a name="281" href="#281">281</a>         <strong>return</strong> hs;
<a name="282" href="#282">282</a>     }
<a name="283" href="#283">283</a> 
<a name="284" href="#284">284</a>     <em>/**<em>*</em></em>
<a name="285" href="#285">285</a> <em>     * Test Archive file is valid.</em>
<a name="286" href="#286">286</a> <em>     * Assumes the stream is at the start of the file.  Be aware that this</em>
<a name="287" href="#287">287</a> <em>     * method makes a pass over the whole file. </em>
<a name="288" href="#288">288</a> <em>     * @return True if file can be successfully parsed.</em>
<a name="289" href="#289">289</a> <em>     */</em>
<a name="290" href="#290">290</a>     <strong>public</strong> <strong>boolean</strong> isValid() {
<a name="291" href="#291">291</a>         <strong>boolean</strong> valid = false;
<a name="292" href="#292">292</a>         <strong>try</strong> {
<a name="293" href="#293">293</a>             validate();
<a name="294" href="#294">294</a>             valid = <strong>true</strong>;
<a name="295" href="#295">295</a>         } <strong>catch</strong>(Exception e) {
<a name="296" href="#296">296</a>             <em class="comment">// File is not valid if exception thrown parsing.</em>
<a name="297" href="#297">297</a>             valid = false;
<a name="298" href="#298">298</a>         }
<a name="299" href="#299">299</a>     
<a name="300" href="#300">300</a>         <strong>return</strong> valid;
<a name="301" href="#301">301</a>     }
<a name="302" href="#302">302</a> 
<a name="303" href="#303">303</a>     <em>/**<em>*</em></em>
<a name="304" href="#304">304</a> <em>     * @return Returns the strict.</em>
<a name="305" href="#305">305</a> <em>     */</em>
<a name="306" href="#306">306</a>     <strong>public</strong> <strong>boolean</strong> isStrict() {
<a name="307" href="#307">307</a>         <strong>return</strong> <strong>this</strong>.strict;
<a name="308" href="#308">308</a>     }
<a name="309" href="#309">309</a> 
<a name="310" href="#310">310</a>     <em>/**<em>*</em></em>
<a name="311" href="#311">311</a> <em>     * @param s The strict to set.</em>
<a name="312" href="#312">312</a> <em>     */</em>
<a name="313" href="#313">313</a>     <strong>public</strong> <strong>void</strong> setStrict(<strong>boolean</strong> s) {
<a name="314" href="#314">314</a>         <strong>this</strong>.strict = s;
<a name="315" href="#315">315</a>     }
<a name="316" href="#316">316</a> 
<a name="317" href="#317">317</a>     <em>/**<em>*</em></em>
<a name="318" href="#318">318</a> <em>     * @param d True if we're to digest.</em>
<a name="319" href="#319">319</a> <em>     */</em>
<a name="320" href="#320">320</a>     <strong>public</strong> <strong>void</strong> setDigest(<strong>boolean</strong> d) {
<a name="321" href="#321">321</a>         <strong>this</strong>.digest = d;
<a name="322" href="#322">322</a>     }
<a name="323" href="#323">323</a> 
<a name="324" href="#324">324</a>     <em>/**<em>*</em></em>
<a name="325" href="#325">325</a> <em>     * @return True if we're digesting as we read.</em>
<a name="326" href="#326">326</a> <em>     */</em>
<a name="327" href="#327">327</a>     <strong>public</strong> <strong>boolean</strong> isDigest() {
<a name="328" href="#328">328</a>         <strong>return</strong> <strong>this</strong>.digest;
<a name="329" href="#329">329</a>     }
<a name="330" href="#330">330</a>  
<a name="331" href="#331">331</a>     <strong>protected</strong> Logger getLogger() {
<a name="332" href="#332">332</a>         <strong>return</strong> Logger.getLogger(<strong>this</strong>.getClass().getName());
<a name="333" href="#333">333</a>     }
<a name="334" href="#334">334</a>     
<a name="335" href="#335">335</a>     <strong>protected</strong> InputStream getInputStream() {
<a name="336" href="#336">336</a>         <strong>return</strong> <strong>this</strong>.in;
<a name="337" href="#337">337</a>     }
<a name="338" href="#338">338</a>     
<a name="339" href="#339">339</a>     <em>/**<em>*</em></em>
<a name="340" href="#340">340</a> <em>     * @return An iterator over ARC records.</em>
<a name="341" href="#341">341</a> <em>     */</em>
<a name="342" href="#342">342</a>     <strong>public</strong> Iterator&lt;ArchiveRecord> iterator() {
<a name="343" href="#343">343</a>         <em class="comment">// Eat up any record outstanding.</em>
<a name="344" href="#344">344</a>         <strong>try</strong> {
<a name="345" href="#345">345</a>             cleanupCurrentRecord();
<a name="346" href="#346">346</a>         } <strong>catch</strong> (IOException e) {
<a name="347" href="#347">347</a>             <strong>throw</strong> <strong>new</strong> RuntimeException(e);
<a name="348" href="#348">348</a>         }
<a name="349" href="#349">349</a>         
<a name="350" href="#350">350</a>         <em class="comment">// Now reset stream to the start of the arc file.</em>
<a name="351" href="#351">351</a>         <strong>try</strong> {
<a name="352" href="#352">352</a>             rewind();
<a name="353" href="#353">353</a>         } <strong>catch</strong> (IOException e) {
<a name="354" href="#354">354</a>             <strong>throw</strong> <strong>new</strong> RuntimeException(e);
<a name="355" href="#355">355</a>         }