writerpool.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="135" href="#135">135</a>         <a href="../../../org/archive/io/WriterPoolMember.html">WriterPoolMember</a> f = <strong>null</strong>;
<a name="136" href="#136">136</a>         <strong>for</strong> (<strong>int</strong> i = 0; f == <strong>null</strong>; i++) {
<a name="137" href="#137">137</a>             <strong>long</strong> waitStart = System.currentTimeMillis();
<a name="138" href="#138">138</a>             <strong>try</strong> {
<a name="139" href="#139">139</a>                 f = (WriterPoolMember)<strong>this</strong>.pool.borrowObject();
<a name="140" href="#140">140</a>                 <strong>if</strong> (logger.getLevel() == Level.FINE) {
<a name="141" href="#141">141</a>                     logger.fine(<span class="string">"Borrowed "</span> + f + <span class="string">" (Pool State: "</span>
<a name="142" href="#142">142</a>                         + getPoolState(waitStart) + <span class="string">")."</span>);
<a name="143" href="#143">143</a>                 }
<a name="144" href="#144">144</a>             } <strong>catch</strong> (NoSuchElementException e) {
<a name="145" href="#145">145</a>                 <em class="comment">// Let this exception out. Unit test at least depends on it.</em>
<a name="146" href="#146">146</a>                 <em class="comment">// Log current state of the pool.</em>
<a name="147" href="#147">147</a>                 logger.warning(e.getMessage() + <span class="string">": Retry #"</span> + i + <span class="string">" of "</span>
<a name="148" href="#148">148</a>                     + <span class="string">" max of "</span> + arbitraryRetryMax
<a name="149" href="#149">149</a>                     + <span class="string">": NSEE Pool State: "</span> + getPoolState(waitStart));
<a name="150" href="#150">150</a>                 <strong>if</strong> (i >= arbitraryRetryMax) {
<a name="151" href="#151">151</a>                     logger.log(Level.SEVERE,
<a name="152" href="#152">152</a>                     	<span class="string">"maximum retries exceeded; rethrowing"</span>,e);
<a name="153" href="#153">153</a>                     <strong>throw</strong> e;
<a name="154" href="#154">154</a>                 }
<a name="155" href="#155">155</a>             } <strong>catch</strong> (Exception e) {
<a name="156" href="#156">156</a>                 <em class="comment">// Convert.</em>
<a name="157" href="#157">157</a>                 logger.severe(e.getMessage() + <span class="string">": E Pool State: "</span> +
<a name="158" href="#158">158</a>                     getPoolState(waitStart));
<a name="159" href="#159">159</a>                 <strong>throw</strong> <strong>new</strong> IOException(<span class="string">"Failed getting writer from pool: "</span> +
<a name="160" href="#160">160</a>                     e.getMessage());
<a name="161" href="#161">161</a>             }
<a name="162" href="#162">162</a>         }
<a name="163" href="#163">163</a>         <strong>return</strong> f;
<a name="164" href="#164">164</a>     }
<a name="165" href="#165">165</a> 
<a name="166" href="#166">166</a> 	<em>/**<em>*</em></em>
<a name="167" href="#167">167</a> <em>	 * @param writer Writer to return to the pool.</em>
<a name="168" href="#168">168</a> <em>	 * @throws IOException Problem returning File to pool.</em>
<a name="169" href="#169">169</a> <em>	 */</em>
<a name="170" href="#170">170</a>     <strong>public</strong> <strong>void</strong> returnFile(<a href="../../../org/archive/io/WriterPoolMember.html">WriterPoolMember</a> writer)
<a name="171" href="#171">171</a>     throws IOException {
<a name="172" href="#172">172</a>         <strong>try</strong> {
<a name="173" href="#173">173</a>             <strong>if</strong> (logger.getLevel() == Level.FINE) {
<a name="174" href="#174">174</a>                 logger.fine(<span class="string">"Returned "</span> + writer);
<a name="175" href="#175">175</a>             }
<a name="176" href="#176">176</a>             <strong>this</strong>.pool.returnObject(writer);
<a name="177" href="#177">177</a>         }
<a name="178" href="#178">178</a>         <strong>catch</strong>(Exception e)
<a name="179" href="#179">179</a>         {
<a name="180" href="#180">180</a>             <strong>throw</strong> <strong>new</strong> IOException(<span class="string">"Failed restoring writer to pool: "</span> +
<a name="181" href="#181">181</a>                     e.getMessage());
<a name="182" href="#182">182</a>         }
<a name="183" href="#183">183</a>     }
<a name="184" href="#184">184</a> 
<a name="185" href="#185">185</a>     <strong>public</strong> <strong>void</strong> invalidateFile(<a href="../../../org/archive/io/WriterPoolMember.html">WriterPoolMember</a> f)
<a name="186" href="#186">186</a>     throws IOException {
<a name="187" href="#187">187</a>         <strong>try</strong> {
<a name="188" href="#188">188</a>             <strong>this</strong>.pool.invalidateObject(f);
<a name="189" href="#189">189</a>         } <strong>catch</strong> (Exception e) {
<a name="190" href="#190">190</a>             <em class="comment">// Convert exception.</em>
<a name="191" href="#191">191</a>             <strong>throw</strong> <strong>new</strong> IOException(e.getMessage());
<a name="192" href="#192">192</a>         }
<a name="193" href="#193">193</a>         <em class="comment">// It'll have been closed.  Rename with an '.invalid' suffix so it</em>
<a name="194" href="#194">194</a>         <em class="comment">// gets attention.</em>
<a name="195" href="#195">195</a>         File file = f.getFile();
<a name="196" href="#196">196</a>         file.renameTo(<strong>new</strong> File(file.getAbsoluteFile() +
<a name="197" href="#197">197</a>                 WriterPoolMember.INVALID_SUFFIX));
<a name="198" href="#198">198</a>     }
<a name="199" href="#199">199</a> 
<a name="200" href="#200">200</a> 	<em>/**<em>*</em></em>
<a name="201" href="#201">201</a> <em>	 * @return Number of {@link WriterPoolMember}s checked out of pool.</em>
<a name="202" href="#202">202</a> <em>	 * @throws java.lang.UnsupportedOperationException</em>
<a name="203" href="#203">203</a> <em>	 */</em>
<a name="204" href="#204">204</a>     <strong>public</strong> <strong>int</strong> getNumActive()
<a name="205" href="#205">205</a>     throws UnsupportedOperationException {
<a name="206" href="#206">206</a>         <strong>return</strong> <strong>this</strong>.pool.getNumActive();
<a name="207" href="#207">207</a>     }
<a name="208" href="#208">208</a> 
<a name="209" href="#209">209</a> 	<em>/**<em>*</em></em>
<a name="210" href="#210">210</a> <em>	 * @return Number of {@link WriterPoolMember} instances still in the pool.</em>
<a name="211" href="#211">211</a> <em>	 * @throws java.lang.UnsupportedOperationException</em>
<a name="212" href="#212">212</a> <em>	 */</em>
<a name="213" href="#213">213</a>     <strong>public</strong> <strong>int</strong> getNumIdle()
<a name="214" href="#214">214</a>     throws UnsupportedOperationException {
<a name="215" href="#215">215</a>         <strong>return</strong> <strong>this</strong>.pool.getNumIdle();
<a name="216" href="#216">216</a>     }
<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>	 * Close all {@link WriterPoolMember}s in pool.</em>
<a name="220" href="#220">220</a> <em>	 */</em>
<a name="221" href="#221">221</a>     <strong>public</strong> <strong>void</strong> close() {
<a name="222" href="#222">222</a>         <strong>this</strong>.pool.clear();
<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>	 * @return Returns settings.</em>
<a name="227" href="#227">227</a> <em>	 */</em>
<a name="228" href="#228">228</a>     <strong>public</strong> <a href="../../../org/archive/io/WriterPoolSettings.html">WriterPoolSettings</a> getSettings() {
<a name="229" href="#229">229</a>         <strong>return</strong> <strong>this</strong>.settings;
<a name="230" href="#230">230</a>     }
<a name="231" href="#231">231</a>     
<a name="232" href="#232">232</a>     <em>/**<em>*</em></em>
<a name="233" href="#233">233</a> <em>     * @return State of the pool string</em>
<a name="234" href="#234">234</a> <em>     */</em>
<a name="235" href="#235">235</a>     <strong>protected</strong> String getPoolState() {
<a name="236" href="#236">236</a>         <strong>return</strong> getPoolState(-1);
<a name="237" href="#237">237</a>     }
<a name="238" href="#238">238</a>     
<a name="239" href="#239">239</a>     <em>/**<em>*</em></em>
<a name="240" href="#240">240</a> <em>     * @param startTime If we are passed a start time, we'll add difference</em>
<a name="241" href="#241">241</a> <em>     * between it and now to end of string.  Pass -1 if don't want this</em>
<a name="242" href="#242">242</a> <em>     * added to end of state string.</em>
<a name="243" href="#243">243</a> <em>     * @return State of the pool string</em>
<a name="244" href="#244">244</a> <em>     */</em>
<a name="245" href="#245">245</a>     <strong>protected</strong> String getPoolState(<strong>long</strong> startTime) {
<a name="246" href="#246">246</a>         StringBuffer buffer = <strong>new</strong> StringBuffer(<span class="string">"Active "</span>);
<a name="247" href="#247">247</a>         buffer.append(getNumActive());
<a name="248" href="#248">248</a>         buffer.append(<span class="string">" of max "</span>);
<a name="249" href="#249">249</a>         buffer.append(<strong>this</strong>.pool.getMaxActive());
<a name="250" href="#250">250</a>         buffer.append(<span class="string">", idle "</span>);
<a name="251" href="#251">251</a>         buffer.append(<strong>this</strong>.pool.getNumIdle());
<a name="252" href="#252">252</a>         <strong>if</strong> (startTime != -1) {
<a name="253" href="#253">253</a>             buffer.append(<span class="string">", time "</span>);
<a name="254" href="#254">254</a>             buffer.append(System.currentTimeMillis() - startTime);
<a name="255" href="#255">255</a>             buffer.append(<span class="string">"ms of max "</span>);
<a name="256" href="#256">256</a>             buffer.append(<strong>this</strong>.pool.getMaxWait());
<a name="257" href="#257">257</a>             buffer.append(<span class="string">"ms"</span>);
<a name="258" href="#258">258</a>         }
<a name="259" href="#259">259</a>         <strong>return</strong> buffer.toString();
<a name="260" href="#260">260</a>     }
<a name="261" href="#261">261</a>     
<a name="262" href="#262">262</a>     <em>/**<em>*</em></em>
<a name="263" href="#263">263</a> <em>     * Returns the atomic integer used to generate serial numbers</em>
<a name="264" href="#264">264</a> <em>     * for files.</em>
<a name="265" href="#265">265</a> <em>     * </em>
<a name="266" href="#266">266</a> <em>     * @return  the serial number generator</em>
<a name="267" href="#267">267</a> <em>     */</em>
<a name="268" href="#268">268</a>     <strong>public</strong> AtomicInteger getSerialNo() {
<a name="269" href="#269">269</a>         <strong>return</strong> serialNo;
<a name="270" href="#270">270</a>     }
<a name="271" href="#271">271</a> }
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