jembeanhelper.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="397" href="#397">397</a> <em>     * @return true if the MBean should regenerate its JE metadata.</em>
<a name="398" href="#398">398</a> <em>     */</em>
<a name="399" href="#399">399</a>     <strong>public</strong> <strong>synchronized</strong> <strong>boolean</strong> getNeedReset() {
<a name="400" href="#400">400</a>         <strong>return</strong> needReset;
<a name="401" href="#401">401</a>     }
<a name="402" href="#402">402</a> 
<a name="403" href="#403">403</a>     <em>/**<em>*******************************************************************/</em></em>
<a name="404" href="#404">404</a>     <em class="comment">/*<em class="comment"> MBean Attributes                                                 */</em></em>
<a name="405" href="#405">405</a>     <em>/**<em>*******************************************************************/</em></em>
<a name="406" href="#406">406</a> 
<a name="407" href="#407">407</a>     <em>/**<em>*</em></em>
<a name="408" href="#408">408</a> <em>     * Get MBean attribute metadata for this environment.</em>
<a name="409" href="#409">409</a> <em>     * @param targetEnv The target JE environment. May be null if the</em>
<a name="410" href="#410">410</a> <em>     * environment is not open.</em>
<a name="411" href="#411">411</a> <em>     * @return list of MBeanAttributeInfo objects describing the available</em>
<a name="412" href="#412">412</a> <em>     * attributes.</em>
<a name="413" href="#413">413</a> <em>     */</em>
<a name="414" href="#414">414</a>     <strong>public</strong> List getAttributeList(Environment targetEnv) {
<a name="415" href="#415">415</a> 
<a name="416" href="#416">416</a>         <em class="comment">/*<em class="comment"> Turn off reset because the mbean metadata is being refreshed. */</em></em>
<a name="417" href="#417">417</a>         setNeedReset(false);
<a name="418" href="#418">418</a> 
<a name="419" href="#419">419</a>         ArrayList attrList = <strong>new</strong> ArrayList();
<a name="420" href="#420">420</a>         
<a name="421" href="#421">421</a>         <em class="comment">/*<em class="comment"> Add attributes for all JE environments. */</em></em>
<a name="422" href="#422">422</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; COMMON_ATTR.length; i++) {
<a name="423" href="#423">423</a>             attrList.add(COMMON_ATTR[i]);
<a name="424" href="#424">424</a>         }
<a name="425" href="#425">425</a> 
<a name="426" href="#426">426</a>         <strong>if</strong> (targetEnv == <strong>null</strong>) {
<a name="427" href="#427">427</a>             <strong>if</strong> (canConfigure) {
<a name="428" href="#428">428</a>                 <em class="comment">/*<em class="comment"> Add attributes for configuring an environment. */</em></em>
<a name="429" href="#429">429</a>                 <strong>for</strong> (<strong>int</strong> i = 0; i &lt; CREATE_ATTR.length; i++) {
<a name="430" href="#430">430</a>                     attrList.add(CREATE_ATTR[i]);
<a name="431" href="#431">431</a>                 }
<a name="432" href="#432">432</a>             }
<a name="433" href="#433">433</a>         } <strong>else</strong> {
<a name="434" href="#434">434</a>             <em class="comment">/*<em class="comment"> Add attributes for an open environment. */</em></em>
<a name="435" href="#435">435</a>             <strong>for</strong> (<strong>int</strong> i = 0; i &lt; OPEN_ATTR.length; i++) {
<a name="436" href="#436">436</a>                 attrList.add(OPEN_ATTR[i]);
<a name="437" href="#437">437</a>             }
<a name="438" href="#438">438</a> 
<a name="439" href="#439">439</a>             <em class="comment">/*<em class="comment"> Add attributes for an open, transactional environment. */</em></em>
<a name="440" href="#440">440</a>             <strong>try</strong> {
<a name="441" href="#441">441</a>                 EnvironmentConfig config = targetEnv.getConfig();
<a name="442" href="#442">442</a>                 <strong>if</strong> (config.getTransactional()) {
<a name="443" href="#443">443</a>                     <strong>for</strong> (<strong>int</strong> i = 0; i &lt; TRANSACTIONAL_ATTR.length; i++) {
<a name="444" href="#444">444</a>                         attrList.add(TRANSACTIONAL_ATTR[i]);
<a name="445" href="#445">445</a>                     }
<a name="446" href="#446">446</a>                 }
<a name="447" href="#447">447</a>             } <strong>catch</strong> (DatabaseException ignore) {
<a name="448" href="#448">448</a>             	<em class="comment">/*<em class="comment"> ignore */</em></em>
<a name="449" href="#449">449</a>             }
<a name="450" href="#450">450</a>         }
<a name="451" href="#451">451</a> 
<a name="452" href="#452">452</a>         <strong>return</strong> attrList;
<a name="453" href="#453">453</a>     }
<a name="454" href="#454">454</a> 
<a name="455" href="#455">455</a>     <em>/**<em>*</em></em>
<a name="456" href="#456">456</a> <em>     * Get an attribute value for the given environment. Check</em>
<a name="457" href="#457">457</a> <em>     * JEMBeanHelper.getNeedReset() after this call because the helper may</em>
<a name="458" href="#458">458</a> <em>     * detect that the environment has changed and that the MBean metadata</em>
<a name="459" href="#459">459</a> <em>     * should be reset.</em>
<a name="460" href="#460">460</a> <em>     *</em>
<a name="461" href="#461">461</a> <em>     * @param targetEnv The target JE environment. May be null if the</em>
<a name="462" href="#462">462</a> <em>     * environment is not open.</em>
<a name="463" href="#463">463</a> <em>     * @param attributeName attribute name.</em>
<a name="464" href="#464">464</a> <em>     * @return attribute value.</em>
<a name="465" href="#465">465</a> <em>     */</em>
<a name="466" href="#466">466</a>     <strong>public</strong> Object getAttribute(Environment targetEnv,
<a name="467" href="#467">467</a>                                String attributeName) 
<a name="468" href="#468">468</a>         throws AttributeNotFoundException,
<a name="469" href="#469">469</a>                MBeanException {
<a name="470" href="#470">470</a> 
<a name="471" href="#471">471</a>         <em class="comment">/*<em class="comment"> Sanity check. */</em></em>
<a name="472" href="#472">472</a>         <strong>if</strong> (attributeName == <strong>null</strong>) {
<a name="473" href="#473">473</a>             <strong>throw</strong> <strong>new</strong> AttributeNotFoundException(
<a name="474" href="#474">474</a>                                             <span class="string">"Attribute name cannot be null"</span>);
<a name="475" href="#475">475</a>         }
<a name="476" href="#476">476</a> 
<a name="477" href="#477">477</a>         <em class="comment">/*<em class="comment"> These attributes are available regardless of environment state. */</em></em>
<a name="478" href="#478">478</a>         <strong>try</strong> {
<a name="479" href="#479">479</a>             <strong>if</strong> (attributeName.equals(ATT_ENV_HOME)) {
<a name="480" href="#480">480</a>                 <strong>return</strong> environmentHome.getCanonicalPath();
<a name="481" href="#481">481</a>             } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_OPEN)) {
<a name="482" href="#482">482</a>                 <strong>boolean</strong> envIsOpen = (targetEnv != <strong>null</strong>);
<a name="483" href="#483">483</a>                 resetIfOpenStateChanged(envIsOpen);
<a name="484" href="#484">484</a>                 <strong>return</strong> <strong>new</strong> Boolean(envIsOpen);
<a name="485" href="#485">485</a>             } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_SET_READ_ONLY)) {
<a name="486" href="#486">486</a>                 <strong>return</strong> <strong>new</strong> Boolean(openConfig.getReadOnly());
<a name="487" href="#487">487</a>             } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_SET_TRANSACTIONAL)) {
<a name="488" href="#488">488</a>                 <strong>return</strong> <strong>new</strong> Boolean(openConfig.getTransactional());
<a name="489" href="#489">489</a>             } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_SET_SERIALIZABLE)) {
<a name="490" href="#490">490</a>                 <strong>return</strong> <strong>new</strong> Boolean(openConfig.getTxnSerializableIsolation());
<a name="491" href="#491">491</a>             } <strong>else</strong> {
<a name="492" href="#492">492</a>                 <em class="comment">/*<em class="comment"> The rest are JE environment attributes. */</em></em>
<a name="493" href="#493">493</a>                 <strong>if</strong> (targetEnv != <strong>null</strong>) {
<a name="494" href="#494">494</a> 
<a name="495" href="#495">495</a>                     EnvironmentConfig config = targetEnv.getConfig();
<a name="496" href="#496">496</a> 
<a name="497" href="#497">497</a>                     <strong>if</strong> (attributeName.equals(ATT_IS_READ_ONLY)) {
<a name="498" href="#498">498</a>                         <strong>return</strong> <strong>new</strong> Boolean(config.getReadOnly());
<a name="499" href="#499">499</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_IS_TRANSACTIONAL)) {
<a name="500" href="#500">500</a>                         <strong>return</strong> <strong>new</strong> Boolean(config.getTransactional());
<a name="501" href="#501">501</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_CACHE_SIZE)) {
<a name="502" href="#502">502</a>                         <strong>return</strong> <strong>new</strong> Long(config.getCacheSize());
<a name="503" href="#503">503</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_CACHE_PERCENT)) {
<a name="504" href="#504">504</a>                         <strong>return</strong> <strong>new</strong> Integer(config.getCachePercent());
<a name="505" href="#505">505</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_LOCK_TIMEOUT)) {
<a name="506" href="#506">506</a>                         <strong>return</strong> <strong>new</strong> Long(config.getLockTimeout());
<a name="507" href="#507">507</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_IS_SERIALIZABLE)) {
<a name="508" href="#508">508</a>                         <strong>return</strong> <strong>new</strong>
<a name="509" href="#509">509</a>                             Boolean(config.getTxnSerializableIsolation());
<a name="510" href="#510">510</a>                     } <strong>else</strong> <strong>if</strong> (attributeName.equals(ATT_TXN_TIMEOUT)) {
<a name="511" href="#511">511</a>                         <strong>return</strong> <strong>new</strong> Long(config.getTxnTimeout());
<a name="512" href="#512">512</a>                     } <strong>else</strong> {
<a name="513" href="#513">513</a>                         <strong>throw</strong> <strong>new</strong> AttributeNotFoundException(<span class="string">"attribute "</span> +
<a name="514" href="#514">514</a>                                                              attributeName +
<a name="515" href="#515">515</a>                                                              <span class="string">" is not valid."</span>);
<a name="516" href="#516">516</a>                     }
<a name="517" href="#517">517</a>                 } 
<a name="518" href="#518">518</a>                 <strong>return</strong> <strong>null</strong>; 
<a name="519" href="#519">519</a>             }
<a name="520" href="#520">520</a>         } <strong>catch</strong> (Exception e) {
<a name="521" href="#521">521</a>             <em class="comment">/*</em>
<a name="522" href="#522">522</a> <em class="comment">             * Add both the message and the exception for easiest deciphering</em>
<a name="523" href="#523">523</a> <em class="comment">             * of the problem. Sometimes the original exception stacktrace gets</em>
<a name="524" href="#524">524</a> <em class="comment">             * hidden in server logs.</em>
<a name="525" href="#525">525</a> <em class="comment">             */</em>
<a name="526" href="#526">526</a>             <strong>throw</strong> <strong>new</strong> MBeanException(e, e.getMessage());
<a name="527" href="#527">527</a>         }
<a name="528" href="#528">528</a>     }
<a name="529" href="#529">529</a> 
<a name="530" href="#530">530</a>     <em>/**<em>*</em></em>
<a name="531" href="#531">531</a> <em>     * Set an attribute value for the given environment.</em>