archiveutils.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="334" href="#334">334</a>                 timestamp = timestamp + <span class="string">"010000"</span>;
<a name="335" href="#335">335</a>             }
<a name="336" href="#336">336</a>             <strong>if</strong> (timestamp.length() &lt; 14) {
<a name="337" href="#337">337</a>                 timestamp = timestamp +
<a name="338" href="#338">338</a>                     ArchiveUtils.padTo(<span class="string">""</span>, 14 - timestamp.length(), '0');
<a name="339" href="#339">339</a>             }
<a name="340" href="#340">340</a>         }
<a name="341" href="#341">341</a>         <strong>return</strong> ArchiveUtils.parse14DigitDate(timestamp);
<a name="342" href="#342">342</a>     }
<a name="343" href="#343">343</a>     
<a name="344" href="#344">344</a>     <em>/**<em>*</em></em>
<a name="345" href="#345">345</a> <em>     * @param i Integer to add prefix of zeros too.  If passed</em>
<a name="346" href="#346">346</a> <em>     * 2005, will return the String &lt;code>0000002005&lt;/code>. String</em>
<a name="347" href="#347">347</a> <em>     * width is the width of Integer.MAX_VALUE as a string (10</em>
<a name="348" href="#348">348</a> <em>     * digits).</em>
<a name="349" href="#349">349</a> <em>     * @return Padded String version of &lt;code>i&lt;/code>.</em>
<a name="350" href="#350">350</a> <em>     */</em>
<a name="351" href="#351">351</a>     <strong>public</strong> <strong>static</strong> String zeroPadInteger(<strong>int</strong> i) {
<a name="352" href="#352">352</a>         <strong>return</strong> ArchiveUtils.padTo(Integer.toString(i),
<a name="353" href="#353">353</a>                 MAX_INT_CHAR_WIDTH, '0');
<a name="354" href="#354">354</a>     }
<a name="355" href="#355">355</a> 
<a name="356" href="#356">356</a>     <em>/**<em>* </em></em>
<a name="357" href="#357">357</a> <em>     * Convert an &lt;code>int&lt;/code> to a &lt;code>String&lt;/code>, and pad it to</em>
<a name="358" href="#358">358</a> <em>     * &lt;code>pad&lt;/code> spaces.</em>
<a name="359" href="#359">359</a> <em>     * @param i the int</em>
<a name="360" href="#360">360</a> <em>     * @param pad the width to pad to.</em>
<a name="361" href="#361">361</a> <em>     * @return String w/ padding.</em>
<a name="362" href="#362">362</a> <em>     */</em>
<a name="363" href="#363">363</a>     <strong>public</strong> <strong>static</strong> String padTo(<strong>final</strong> <strong>int</strong> i, <strong>final</strong> <strong>int</strong> pad) {
<a name="364" href="#364">364</a>         String n = Integer.toString(i);
<a name="365" href="#365">365</a>         <strong>return</strong> padTo(n, pad);
<a name="366" href="#366">366</a>     }
<a name="367" href="#367">367</a>     
<a name="368" href="#368">368</a>     <em>/**<em>* </em></em>
<a name="369" href="#369">369</a> <em>     * Pad the given &lt;code>String&lt;/code> to &lt;code>pad&lt;/code> characters wide</em>
<a name="370" href="#370">370</a> <em>     * by pre-pending spaces.  &lt;code>s&lt;/code> should not be &lt;code>null&lt;/code>.</em>
<a name="371" href="#371">371</a> <em>     * If &lt;code>s&lt;/code> is already wider than &lt;code>pad&lt;/code> no change is</em>
<a name="372" href="#372">372</a> <em>     * done.</em>
<a name="373" href="#373">373</a> <em>     *</em>
<a name="374" href="#374">374</a> <em>     * @param s the String to pad</em>
<a name="375" href="#375">375</a> <em>     * @param pad the width to pad to.</em>
<a name="376" href="#376">376</a> <em>     * @return String w/ padding.</em>
<a name="377" href="#377">377</a> <em>     */</em>
<a name="378" href="#378">378</a>     <strong>public</strong> <strong>static</strong> String padTo(<strong>final</strong> String s, <strong>final</strong> <strong>int</strong> pad) {
<a name="379" href="#379">379</a>         <strong>return</strong> padTo(s, pad, DEFAULT_PAD_CHAR);
<a name="380" href="#380">380</a>     }
<a name="381" href="#381">381</a> 
<a name="382" href="#382">382</a>     <em>/**<em>* </em></em>
<a name="383" href="#383">383</a> <em>     * Pad the given &lt;code>String&lt;/code> to &lt;code>pad&lt;/code> characters wide</em>
<a name="384" href="#384">384</a> <em>     * by pre-pending &lt;code>padChar&lt;/code>.</em>
<a name="385" href="#385">385</a> <em>     * </em>
<a name="386" href="#386">386</a> <em>     * &lt;code>s&lt;/code> should not be &lt;code>null&lt;/code>. If &lt;code>s&lt;/code> is</em>
<a name="387" href="#387">387</a> <em>     * already wider than &lt;code>pad&lt;/code> no change is done.</em>
<a name="388" href="#388">388</a> <em>     *</em>
<a name="389" href="#389">389</a> <em>     * @param s the String to pad</em>
<a name="390" href="#390">390</a> <em>     * @param pad the width to pad to.</em>
<a name="391" href="#391">391</a> <em>     * @param padChar The pad character to use.</em>
<a name="392" href="#392">392</a> <em>     * @return String w/ padding.</em>
<a name="393" href="#393">393</a> <em>     */</em>
<a name="394" href="#394">394</a>     <strong>public</strong> <strong>static</strong> String padTo(<strong>final</strong> String s, <strong>final</strong> <strong>int</strong> pad,
<a name="395" href="#395">395</a>             <strong>final</strong> <strong>char</strong> padChar) {
<a name="396" href="#396">396</a>         String result = s;
<a name="397" href="#397">397</a>         <strong>int</strong> l = s.length();
<a name="398" href="#398">398</a>         <strong>if</strong> (l &lt; pad) {
<a name="399" href="#399">399</a>             StringBuffer sb = <strong>new</strong> StringBuffer(pad);
<a name="400" href="#400">400</a>             <strong>while</strong>(l &lt; pad) {
<a name="401" href="#401">401</a>                 sb.append(padChar);
<a name="402" href="#402">402</a>                 l++;
<a name="403" href="#403">403</a>             }
<a name="404" href="#404">404</a>             sb.append(s);
<a name="405" href="#405">405</a>             result = sb.toString();
<a name="406" href="#406">406</a>         }
<a name="407" href="#407">407</a>         <strong>return</strong> result;
<a name="408" href="#408">408</a>     }
<a name="409" href="#409">409</a> 
<a name="410" href="#410">410</a>     <em>/**<em>* check that two byte arrays are equal.  They may be &lt;code>null&lt;/code>.</em></em>
<a name="411" href="#411">411</a> <em>     *</em>
<a name="412" href="#412">412</a> <em>     * @param lhs a byte array</em>
<a name="413" href="#413">413</a> <em>     * @param rhs another byte array.</em>
<a name="414" href="#414">414</a> <em>     * @return &lt;code>true&lt;/code> if they are both equal (or both</em>
<a name="415" href="#415">415</a> <em>     * &lt;code>null&lt;/code>)</em>
<a name="416" href="#416">416</a> <em>     */</em>
<a name="417" href="#417">417</a>     <strong>public</strong> <strong>static</strong> <strong>boolean</strong> byteArrayEquals(<strong>final</strong> byte[] lhs, <strong>final</strong> byte[] rhs) {
<a name="418" href="#418">418</a>         <strong>if</strong> (lhs == <strong>null</strong> &amp;&amp; rhs != <strong>null</strong> || lhs != <strong>null</strong> &amp;&amp; rhs == <strong>null</strong>) {
<a name="419" href="#419">419</a>             <strong>return</strong> false;
<a name="420" href="#420">420</a>         }
<a name="421" href="#421">421</a>         <strong>if</strong> (lhs==rhs) {
<a name="422" href="#422">422</a>             <strong>return</strong> <strong>true</strong>;
<a name="423" href="#423">423</a>         }
<a name="424" href="#424">424</a>         <strong>if</strong> (lhs.length != rhs.length) {
<a name="425" href="#425">425</a>             <strong>return</strong> false;
<a name="426" href="#426">426</a>         }
<a name="427" href="#427">427</a>         <strong>for</strong>(<strong>int</strong> i = 0; i&lt;lhs.length; i++) {
<a name="428" href="#428">428</a>             <strong>if</strong> (lhs[i]!=rhs[i]) {
<a name="429" href="#429">429</a>                 <strong>return</strong> false;
<a name="430" href="#430">430</a>             }
<a name="431" href="#431">431</a>         }
<a name="432" href="#432">432</a>         <strong>return</strong> <strong>true</strong>;
<a name="433" href="#433">433</a>     }
<a name="434" href="#434">434</a> 
<a name="435" href="#435">435</a>     <em>/**<em>*</em></em>
<a name="436" href="#436">436</a> <em>     * Converts a double to a string.</em>
<a name="437" href="#437">437</a> <em>     * @param val The double to convert</em>
<a name="438" href="#438">438</a> <em>     * @param precision How many characters to include after '.'</em>
<a name="439" href="#439">439</a> <em>     * @return the double as a string.</em>
<a name="440" href="#440">440</a> <em>     */</em>
<a name="441" href="#441">441</a>     <strong>public</strong> <strong>static</strong> String <strong>double</strong>ToString(<strong>double</strong> val, <strong>int</strong> precision){
<a name="442" href="#442">442</a>         String tmp = Double.toString(val);
<a name="443" href="#443">443</a>         <strong>if</strong>(tmp.indexOf(<span class="string">"."</span>)!=-1){
<a name="444" href="#444">444</a>             <em class="comment">// Need to handle the part after '.'</em>
<a name="445" href="#445">445</a>             <strong>if</strong>(precision&lt;=0){
<a name="446" href="#446">446</a>                 tmp = tmp.substring(0,tmp.indexOf('.'));
<a name="447" href="#447">447</a>             } <strong>else</strong> {
<a name="448" href="#448">448</a>                 <strong>if</strong>(tmp.length()>tmp.indexOf('.')+precision+1){
<a name="449" href="#449">449</a>                     <em class="comment">// Need to trim</em>
<a name="450" href="#450">450</a>                     tmp = tmp.substring(0,tmp.indexOf('.')+precision+1);
<a name="451" href="#451">451</a>                 }
<a name="452" href="#452">452</a>             }
<a name="453" href="#453">453</a>         }
<a name="454" href="#454">454</a>         <strong>return</strong> tmp;
<a name="455" href="#455">455</a>     }
<a name="456" href="#456">456</a> 
<a name="457" href="#457">457</a>     <em>/**<em>*</em></em>
<a name="458" href="#458">458</a> <em>     * Takes an amount of bytes and formats it for display. This involves</em>
<a name="459" href="#459">459</a> <em>     * converting it to Kb, Mb or Gb if the amount is enough to qualify for</em>
<a name="460" href="#460">460</a> <em>     * the next level.</em>
<a name="461" href="#461">461</a> <em>     * &lt;p></em>
<a name="462" href="#462">462</a> <em>     * Displays as bytes (B): 0-1023</em>
<a name="463" href="#463">463</a> <em>     * Displays as kilobytes (KB): 1024 - 2097151 (~2Mb)</em>
<a name="464" href="#464">464</a> <em>     * Displays as megabytes (MB): 2097152 - 4294967295 (~4Gb)</em>
<a name="465" href="#465">465</a> <em>     * Displays as gigabytes (GB): 4294967296 - infinity</em>
<a name="466" href="#466">466</a> <em>     * &lt;p></em>
<a name="467" href="#467">467</a> <em>     * Negative numbers will be returned as '0 B'.</em>
<a name="468" href="#468">468</a> <em>     * &lt;p></em>
<a name="469" href="#469">469</a> <em>     * All values will be approximated down (i.e. 2047 bytes are 1 KB)</em>
<a name="470" href="#470">470</a> <em>     *</em>
<a name="471" href="#471">471</a> <em>     * @param amount the amount of bytes</em>
<a name="472" href="#472">472</a> <em>     * @return A string containing the amount, properly formated.</em>
<a name="473" href="#473">473</a> <em>     */</em>
<a name="474" href="#474">474</a>     <strong>public</strong> <strong>static</strong> String formatBytesForDisplay(<strong>long</strong> amount){
<a name="475" href="#475">475</a>         <strong>long</strong> kbStartAt = 1024;
<a name="476" href="#476">476</a>         <strong>long</strong> mbStartAt = 1024*1024*2;
<a name="477" href="#477">477</a>         <strong>long</strong> gbStartAt = ((<strong>long</strong>)1024*1024)*1024*4;
<a name="478" href="#478">478</a> 
<a name="479" href="#479">479</a>         <strong>if</strong>(amount &lt; 0){
<a name="480" href="#480">480</a>             <strong>return</strong> <span class="string">"0 B"</span>;
<a name="481" href="#481">481</a>         }
<a name="482" href="#482">482</a>         <strong>else</strong> <strong>if</strong>(amount &lt; kbStartAt){
<a name="483" href="#483">483</a>             <em class="comment">// Display as bytes.</em>
<a name="484" href="#484">484</a>             <strong>return</strong> amount + <span class="string">" B"</span>;
<a name="485" href="#485">485</a>         } <strong>else</strong> <strong>if</strong>(amount &lt; mbStartAt) {
<a name="486" href="#486">486</a>             <em class="comment">// Display as kilobytes</em>
<a name="487" href="#487">487</a>             <strong>return</strong> Long.toString((<strong>long</strong>)(((<strong>double</strong>)amount/1024)))+<span class="string">" KB"</span>;
<a name="488" href="#488">488</a>         } <strong>else</strong> <strong>if</strong>(amount &lt; gbStartAt) {
<a name="489" href="#489">489</a>             <em class="comment">// Display as megabytes</em>
<a name="490" href="#490">490</a>             <strong>return</strong> Long.toString((<strong>long</strong>)(((<strong>double</strong>)amount/(1024*1024))))+<span class="string">" MB"</span>;
<a name="491" href="#491">491</a>         } <strong>else</strong> {
<a name="492" href="#492">492</a>             <em class="comment">// Display as gigabytes</em>
<a name="493" href="#493">493</a>             <strong>return</strong> Long.toString((<strong>long</strong>)(((<strong>double</strong>)amount/(1024*1024*1024))))+<span class="string">" GB"</span>;
<a name="494" href="#494">494</a>         }
<a name="495" href="#495">495</a>     }
<a name="496" href="#496">496</a> 
<a name="497" href="#497">497</a>     <em>/**<em>*</em></em>
<a name="498" href="#498">498</a> <em>     * Convert milliseconds value to a human-readable duration</em>
<a name="499" href="#499">499</a> <em>     * @param time</em>
<a name="500" href="#500">500</a> <em>     * @return Human readable string version of passed &lt;code>time&lt;/code></em>
<a name="501" href="#501">501</a> <em>     */</em>
<a name="502" href="#502">502</a>     <strong>public</strong> <strong>static</strong> String formatMillisecondsToConventional(<strong>long</strong> time) {
<a name="503" href="#503">503</a>         <strong>return</strong> formatMillisecondsToConventional(time,<strong>true</strong>);
<a name="504" href="#504">504</a>     }