archiveutils.html

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<a name="448" href="#448">448</a>     
<a name="449" href="#449">449</a>     <em>/**<em>* </em></em>
<a name="450" href="#450">450</a> <em>     * Pad the given &lt;code>String&lt;/code> to &lt;code>pad&lt;/code> characters wide</em>
<a name="451" href="#451">451</a> <em>     * by pre-pending spaces.  &lt;code>s&lt;/code> should not be &lt;code>null&lt;/code>.</em>
<a name="452" href="#452">452</a> <em>     * If &lt;code>s&lt;/code> is already wider than &lt;code>pad&lt;/code> no change is</em>
<a name="453" href="#453">453</a> <em>     * done.</em>
<a name="454" href="#454">454</a> <em>     *</em>
<a name="455" href="#455">455</a> <em>     * @param s the String to pad</em>
<a name="456" href="#456">456</a> <em>     * @param pad the width to pad to.</em>
<a name="457" href="#457">457</a> <em>     * @return String w/ padding.</em>
<a name="458" href="#458">458</a> <em>     */</em>
<a name="459" href="#459">459</a>     <strong>public</strong> <strong>static</strong> String padTo(<strong>final</strong> String s, <strong>final</strong> <strong>int</strong> pad) {
<a name="460" href="#460">460</a>         <strong>return</strong> padTo(s, pad, DEFAULT_PAD_CHAR);
<a name="461" href="#461">461</a>     }
<a name="462" href="#462">462</a> 
<a name="463" href="#463">463</a>     <em>/**<em>* </em></em>
<a name="464" href="#464">464</a> <em>     * Pad the given &lt;code>String&lt;/code> to &lt;code>pad&lt;/code> characters wide</em>
<a name="465" href="#465">465</a> <em>     * by pre-pending &lt;code>padChar&lt;/code>.</em>
<a name="466" href="#466">466</a> <em>     * </em>
<a name="467" href="#467">467</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="468" href="#468">468</a> <em>     * already wider than &lt;code>pad&lt;/code> no change is done.</em>
<a name="469" href="#469">469</a> <em>     *</em>
<a name="470" href="#470">470</a> <em>     * @param s the String to pad</em>
<a name="471" href="#471">471</a> <em>     * @param pad the width to pad to.</em>
<a name="472" href="#472">472</a> <em>     * @param padChar The pad character to use.</em>
<a name="473" href="#473">473</a> <em>     * @return String w/ padding.</em>
<a name="474" href="#474">474</a> <em>     */</em>
<a name="475" href="#475">475</a>     <strong>public</strong> <strong>static</strong> String padTo(<strong>final</strong> String s, <strong>final</strong> <strong>int</strong> pad,
<a name="476" href="#476">476</a>             <strong>final</strong> <strong>char</strong> padChar) {
<a name="477" href="#477">477</a>         String result = s;
<a name="478" href="#478">478</a>         <strong>int</strong> l = s.length();
<a name="479" href="#479">479</a>         <strong>if</strong> (l &lt; pad) {
<a name="480" href="#480">480</a>             StringBuffer sb = <strong>new</strong> StringBuffer(pad);
<a name="481" href="#481">481</a>             <strong>while</strong>(l &lt; pad) {
<a name="482" href="#482">482</a>                 sb.append(padChar);
<a name="483" href="#483">483</a>                 l++;
<a name="484" href="#484">484</a>             }
<a name="485" href="#485">485</a>             sb.append(s);
<a name="486" href="#486">486</a>             result = sb.toString();
<a name="487" href="#487">487</a>         }
<a name="488" href="#488">488</a>         <strong>return</strong> result;
<a name="489" href="#489">489</a>     }
<a name="490" href="#490">490</a> 
<a name="491" href="#491">491</a>     <em>/**<em>* check that two byte arrays are equal.  They may be &lt;code>null&lt;/code>.</em></em>
<a name="492" href="#492">492</a> <em>     *</em>
<a name="493" href="#493">493</a> <em>     * @param lhs a byte array</em>
<a name="494" href="#494">494</a> <em>     * @param rhs another byte array.</em>
<a name="495" href="#495">495</a> <em>     * @return &lt;code>true&lt;/code> if they are both equal (or both</em>
<a name="496" href="#496">496</a> <em>     * &lt;code>null&lt;/code>)</em>
<a name="497" href="#497">497</a> <em>     */</em>
<a name="498" href="#498">498</a>     <strong>public</strong> <strong>static</strong> <strong>boolean</strong> byteArrayEquals(<strong>final</strong> byte[] lhs, <strong>final</strong> byte[] rhs) {
<a name="499" href="#499">499</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="500" href="#500">500</a>             <strong>return</strong> false;
<a name="501" href="#501">501</a>         }
<a name="502" href="#502">502</a>         <strong>if</strong> (lhs==rhs) {
<a name="503" href="#503">503</a>             <strong>return</strong> <strong>true</strong>;
<a name="504" href="#504">504</a>         }
<a name="505" href="#505">505</a>         <strong>if</strong> (lhs.length != rhs.length) {
<a name="506" href="#506">506</a>             <strong>return</strong> false;
<a name="507" href="#507">507</a>         }
<a name="508" href="#508">508</a>         <strong>for</strong>(<strong>int</strong> i = 0; i&lt;lhs.length; i++) {
<a name="509" href="#509">509</a>             <strong>if</strong> (lhs[i]!=rhs[i]) {
<a name="510" href="#510">510</a>                 <strong>return</strong> false;
<a name="511" href="#511">511</a>             }
<a name="512" href="#512">512</a>         }
<a name="513" href="#513">513</a>         <strong>return</strong> <strong>true</strong>;
<a name="514" href="#514">514</a>     }
<a name="515" href="#515">515</a> 
<a name="516" href="#516">516</a>     <em>/**<em>*</em></em>
<a name="517" href="#517">517</a> <em>     * Converts a double to a string.</em>
<a name="518" href="#518">518</a> <em>     * @param val The double to convert</em>
<a name="519" href="#519">519</a> <em>     * @param precision How many characters to include after '.'</em>
<a name="520" href="#520">520</a> <em>     * @return the double as a string.</em>
<a name="521" href="#521">521</a> <em>     */</em>
<a name="522" href="#522">522</a>     <strong>public</strong> <strong>static</strong> String <strong>double</strong>ToString(<strong>double</strong> val, <strong>int</strong> maxFractionDigits){
<a name="523" href="#523">523</a>         <strong>return</strong> doubleToString(val, maxFractionDigits, 0);
<a name="524" href="#524">524</a>     }
<a name="525" href="#525">525</a> 
<a name="526" href="#526">526</a>     <strong>private</strong> <strong>static</strong> String <strong>double</strong>ToString(<strong>double</strong> val, <strong>int</strong> maxFractionDigits, <strong>int</strong> minFractionDigits) {
<a name="527" href="#527">527</a>         NumberFormat f = NumberFormat.getNumberInstance(Locale.US); 
<a name="528" href="#528">528</a>         f.setMaximumFractionDigits(maxFractionDigits);
<a name="529" href="#529">529</a>         f.setMinimumFractionDigits(minFractionDigits);
<a name="530" href="#530">530</a>         <strong>return</strong> f.format(val); 
<a name="531" href="#531">531</a>     }
<a name="532" href="#532">532</a> 
<a name="533" href="#533">533</a>     <em>/**<em>*</em></em>
<a name="534" href="#534">534</a> <em>     * Takes a byte size and formats it for display with 'friendly' units. </em>
<a name="535" href="#535">535</a> <em>     * &lt;p></em>
<a name="536" href="#536">536</a> <em>     * This involves converting it to the largest unit </em>
<a name="537" href="#537">537</a> <em>     * (of B, KB, MB, GB, TB) for which the amount will be > 1.</em>
<a name="538" href="#538">538</a> <em>     * &lt;p></em>
<a name="539" href="#539">539</a> <em>     * Additionally, at least 2 significant digits are always displayed. </em>
<a name="540" href="#540">540</a> <em>     * &lt;p></em>
<a name="541" href="#541">541</a> <em>     * Displays as bytes (B): 0-1023</em>
<a name="542" href="#542">542</a> <em>     * Displays as kilobytes (KB): 1024 - 2097151 (~2Mb)</em>
<a name="543" href="#543">543</a> <em>     * Displays as megabytes (MB): 2097152 - 4294967295 (~4Gb)</em>
<a name="544" href="#544">544</a> <em>     * Displays as gigabytes (GB): 4294967296 - infinity</em>
<a name="545" href="#545">545</a> <em>     * &lt;p></em>
<a name="546" href="#546">546</a> <em>     * Negative numbers will be returned as '0 B'.</em>
<a name="547" href="#547">547</a> <em>     *</em>
<a name="548" href="#548">548</a> <em>     * @param amount the amount of bytes</em>
<a name="549" href="#549">549</a> <em>     * @return A string containing the amount, properly formated.</em>
<a name="550" href="#550">550</a> <em>     */</em>
<a name="551" href="#551">551</a>     <strong>public</strong> <strong>static</strong> String formatBytesForDisplay(<strong>long</strong> amount) {
<a name="552" href="#552">552</a>         <strong>double</strong> displayAmount = (<strong>double</strong>) amount;
<a name="553" href="#553">553</a>         <strong>int</strong> unitPowerOf1024 = 0; 
<a name="554" href="#554">554</a> 
<a name="555" href="#555">555</a>         <strong>if</strong>(amount &lt;= 0){
<a name="556" href="#556">556</a>             <strong>return</strong> <span class="string">"0 B"</span>;
<a name="557" href="#557">557</a>         }
<a name="558" href="#558">558</a>         
<a name="559" href="#559">559</a>         <strong>while</strong>(displayAmount>=1024 &amp;&amp; unitPowerOf1024 &lt; 4) {
<a name="560" href="#560">560</a>             displayAmount = displayAmount / 1024;
<a name="561" href="#561">561</a>             unitPowerOf1024++;
<a name="562" href="#562">562</a>         }
<a name="563" href="#563">563</a>         
<a name="564" href="#564">564</a>         <em class="comment">// TODO: get didactic, make these KiB, MiB, GiB, TiB</em>
<a name="565" href="#565">565</a>         <strong>final</strong> String[] units = { <span class="string">" B"</span>, <span class="string">" KB"</span>, <span class="string">" MB"</span>, <span class="string">" GB"</span>, <span class="string">" TB"</span> };
<a name="566" href="#566">566</a>         
<a name="567" href="#567">567</a>         <em class="comment">// ensure at least 2 significant digits (#.#) for small displayValues</em>
<a name="568" href="#568">568</a>         <strong>int</strong> fractionDigits = (displayAmount &lt; 10) ? 1 : 0; 
<a name="569" href="#569">569</a>         <strong>return</strong> doubleToString(displayAmount, fractionDigits, fractionDigits) 
<a name="570" href="#570">570</a>                    + units[unitPowerOf1024];
<a name="571" href="#571">571</a>     }
<a name="572" href="#572">572</a> 
<a name="573" href="#573">573</a>     <em>/**<em>*</em></em>
<a name="574" href="#574">574</a> <em>     * Convert milliseconds value to a human-readable duration</em>
<a name="575" href="#575">575</a> <em>     * @param time</em>
<a name="576" href="#576">576</a> <em>     * @return Human readable string version of passed &lt;code>time&lt;/code></em>
<a name="577" href="#577">577</a> <em>     */</em>
<a name="578" href="#578">578</a>     <strong>public</strong> <strong>static</strong> String formatMillisecondsToConventional(<strong>long</strong> time) {
<a name="579" href="#579">579</a>         <strong>return</strong> formatMillisecondsToConventional(time,<strong>true</strong>);
<a name="580" href="#580">580</a>     }
<a name="581" href="#581">581</a>     
<a name="582" href="#582">582</a>     <em>/**<em>*</em></em>
<a name="583" href="#583">583</a> <em>     * Convert milliseconds value to a human-readable duration</em>
<a name="584" href="#584">584</a> <em>     * @param time</em>
<a name="585" href="#585">585</a> <em>     * @param toMs whether to print to the ms</em>
<a name="586" href="#586">586</a> <em>     * @return Human readable string version of passed &lt;code>time&lt;/code></em>
<a name="587" href="#587">587</a> <em>     */</em>
<a name="588" href="#588">588</a>     <strong>public</strong> <strong>static</strong> String formatMillisecondsToConventional(<strong>long</strong> time, <strong>boolean</strong> toMs) {
<a name="589" href="#589">589</a>         StringBuffer sb = <strong>new</strong> StringBuffer();
<a name="590" href="#590">590</a>         <strong>if</strong>(time&lt;0) {
<a name="591" href="#591">591</a>             sb.append(<span class="string">"-"</span>);
<a name="592" href="#592">592</a>         }
<a name="593" href="#593">593</a>         <strong>long</strong> absTime = Math.abs(time);
<a name="594" href="#594">594</a>         <strong>if</strong>(!toMs &amp;&amp; absTime &lt; 1000) {
<a name="595" href="#595">595</a>             <strong>return</strong> <span class="string">"0s"</span>;
<a name="596" href="#596">596</a>         }
<a name="597" href="#597">597</a>         <strong>if</strong>(absTime > DAY_IN_MS) {
<a name="598" href="#598">598</a>             <em class="comment">// days</em>
<a name="599" href="#599">599</a>             sb.append(absTime / DAY_IN_MS + <span class="string">"d"</span>);