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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="content-type" content="text/html; charset=ISO-8859-1" /><title>KeyedObjectPool xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/apache/commons/pool/KeyedObjectPool.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*</em><a name="2" href="#2">2</a> <em class="comment"> * Copyright 1999-2004 The Apache Software Foundation.</em><a name="3" href="#3">3</a> <em class="comment"> * </em><a name="4" href="#4">4</a> <em class="comment"> * Licensed under the Apache License, Version 2.0 (the "License");</em><a name="5" href="#5">5</a> <em class="comment"> * you may not use this file except in compliance with the License.</em><a name="6" href="#6">6</a> <em class="comment"> * You may obtain a copy of the License at</em><a name="7" href="#7">7</a> <em class="comment"> * </em><a name="8" href="#8">8</a> <em class="comment"> * <a href="http://www.apache.org/licenses/LICENSE-2.0" target="alexandria_uri">http://www.apache.org/licenses/LICENSE-2.0</a></em><a name="9" href="#9">9</a> <em class="comment"> * </em><a name="10" href="#10">10</a> <em class="comment"> * Unless required by applicable law or agreed to in writing, software</em><a name="11" href="#11">11</a> <em class="comment"> * distributed under the License is distributed on an "AS IS" BASIS,</em><a name="12" href="#12">12</a> <em class="comment"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</em><a name="13" href="#13">13</a> <em class="comment"> * See the License for the specific language governing permissions and</em><a name="14" href="#14">14</a> <em class="comment"> * limitations under the License.</em><a name="15" href="#15">15</a> <em class="comment"> */</em><a name="16" href="#16">16</a> <a name="17" href="#17">17</a> <strong>package</strong> <a href="../../../../org/apache/commons/pool/package-summary.html">org.apache.commons.pool</a>;<a name="18" href="#18">18</a> <a name="19" href="#19">19</a> <em>/**<em>*</em></em><a name="20" href="#20">20</a> <em> * A "keyed" pooling interface.</em><a name="21" href="#21">21</a> <em> * <p></em><a name="22" href="#22">22</a> <em> * A keyed pool pools instances of multiple types. Each</em><a name="23" href="#23">23</a> <em> * type may be accessed using an arbitrary key.</em><a name="24" href="#24">24</a> <em> * <p></em><a name="25" href="#25">25</a> <em> * Example of use:</em><a name="26" href="#26">26</a> <em> * <table border="1" cellspacing="0" cellpadding="3" align="center" bgcolor="#FFFFFF"><tr><td><pre></em><a name="27" href="#27">27</a> <em> * Object obj = <font color="#0000CC">null</font>;</em><a name="28" href="#28">28</a> <em> * Object key = <font color="#CC0000">"Key"</font>;</em><a name="29" href="#29">29</a> <em> *</em><a name="30" href="#30">30</a> <em> * <font color="#0000CC">try</font> {</em><a name="31" href="#31">31</a> <em> * obj = pool.borrowObject(key);</em><a name="32" href="#32">32</a> <em> * <font color="#00CC00">//...use the object...</font></em><a name="33" href="#33">33</a> <em> * } <font color="#0000CC">catch</font>(Exception e) {</em><a name="34" href="#34">34</a> <em> * <font color="#00CC00">//...handle any exceptions...</font></em><a name="35" href="#35">35</a> <em> * } <font color="#0000CC">finally</font> {</em><a name="36" href="#36">36</a> <em> * <font color="#00CC00">// make sure the object is returned to the pool</font></em><a name="37" href="#37">37</a> <em> * <font color="#0000CC">if</font>(<font color="#0000CC">null</font> != obj) {</em><a name="38" href="#38">38</a> <em> * pool.returnObject(key,obj);</em><a name="39" href="#39">39</a> <em> * }</em><a name="40" href="#40">40</a> <em> * }</pre></td></tr></table></em><a name="41" href="#41">41</a> <em> *</em><a name="42" href="#42">42</a> <em> * <p></em><a name="43" href="#43">43</a> <em> * {@link KeyedObjectPool} implementations <i>may</i> choose to store at most</em><a name="44" href="#44">44</a> <em> * one instance per key value, or may choose to maintain a pool of instances</em><a name="45" href="#45">45</a> <em> * for each key (essentially creating a {@link java.util.Map Map} of</em><a name="46" href="#46">46</a> <em> * {@link ObjectPool pools}).</em><a name="47" href="#47">47</a> <em> * </p></em><a name="48" href="#48">48</a> <em> *</em><a name="49" href="#49">49</a> <em> * @see KeyedPoolableObjectFactory</em><a name="50" href="#50">50</a> <em> * @see KeyedObjectPoolFactory</em><a name="51" href="#51">51</a> <em> * @see ObjectPool</em><a name="52" href="#52">52</a> <em> *</em><a name="53" href="#53">53</a> <em> * @author Rodney Waldhoff</em><a name="54" href="#54">54</a> <em> * @version $Revision: 155430 $ $Date: 2005-02-26 08:13:28 -0500 (Sat, 26 Feb 2005) $</em><a name="55" href="#55">55</a> <em> */</em><a name="56" href="#56">56</a> <strong>public</strong> <strong>interface</strong> <a href="../../../../org/apache/commons/pool/KeyedObjectPool.html">KeyedObjectPool</a> {<a name="57" href="#57">57</a> <em>/**<em>*</em></em><a name="58" href="#58">58</a> <em> * Obtain an instance from my pool</em><a name="59" href="#59">59</a> <em> * for the specified <i>key</i>.</em><a name="60" href="#60">60</a> <em> * By contract, clients MUST return</em><a name="61" href="#61">61</a> <em> * the borrowed object using</em><a name="62" href="#62">62</a> <em> * {@link #returnObject(java.lang.Object,java.lang.Object) <tt>returnObject</tt>},</em><a name="63" href="#63">63</a> <em> * or a related method as defined in an implementation</em><a name="64" href="#64">64</a> <em> * or sub-interface,</em><a name="65" href="#65">65</a> <em> * using a <i>key</i> that is equivalent to the one used to</em><a name="66" href="#66">66</a> <em> * borrow the instance in the first place.</em><a name="67" href="#67">67</a> <em> *</em><a name="68" href="#68">68</a> <em> * @param key the key used to obtain the object</em><a name="69" href="#69">69</a> <em> * @return an instance from my pool.</em><a name="70" href="#70">70</a> <em> */</em><a name="71" href="#71">71</a> Object borrowObject(Object key) throws Exception;<a name="72" href="#72">72</a> <a name="73" href="#73">73</a> <em>/**<em>*</em></em><a name="74" href="#74">74</a> <em> * Return an instance to my pool.</em><a name="75" href="#75">75</a> <em> * By contract, <i>obj</i> MUST have been obtained</em><a name="76" href="#76">76</a> <em> * using {@link #borrowObject(java.lang.Object) <tt>borrowObject</tt>}</em><a name="77" href="#77">77</a> <em> * or a related method as defined in an implementation</em><a name="78" href="#78">78</a> <em> * or sub-interface </em><a name="79" href="#79">79</a> <em> * using a <i>key</i> that is equivalent to the one used to</em><a name="80" href="#80">80</a> <em> * borrow the <tt>Object</tt> in the first place.</em><a name="81" href="#81">81</a> <em> *</em><a name="82" href="#82">82</a> <em> * @param key the key used to obtain the object</em><a name="83" href="#83">83</a> <em> * @param obj a {@link #borrowObject(java.lang.Object) borrowed} instance to be returned.</em><a name="84" href="#84">84</a> <em> */</em><a name="85" href="#85">85</a> <strong>void</strong> returnObject(Object key, Object obj) throws Exception;<a name="86" href="#86">86</a> <a name="87" href="#87">87</a> <em>/**<em>*</em></em><a name="88" href="#88">88</a> <em> * Invalidates an object from the pool</em><a name="89" href="#89">89</a> <em> * By contract, <i>obj</i> MUST have been obtained</em><a name="90" href="#90">90</a> <em> * using {@link #borrowObject borrowObject}</em><a name="91" href="#91">91</a> <em> * or a related method as defined in an implementation</em><a name="92" href="#92">92</a> <em> * or sub-interface </em><a name="93" href="#93">93</a> <em> * using a <i>key</i> that is equivalent to the one used to</em><a name="94" href="#94">94</a> <em> * borrow the <tt>Object</tt> in the first place.</em><a name="95" href="#95">95</a> <em> * <p></em><a name="96" href="#96">96</a> <em> * This method should be used when an object that has been borrowed</em><a name="97" href="#97">97</a> <em> * is determined (due to an exception or other problem) to be invalid.</em>⌨️ 快捷键说明
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