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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>ObjectPool xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/apache/commons/pool/ObjectPool.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 pooling interface.</em><a name="21" href="#21">21</a> <em> * <p></em><a name="22" href="#22">22</a> <em> * <code>ObjectPool</code> defines a trivially simple pooling interface. The only </em><a name="23" href="#23">23</a> <em> * required methods are {@link #borrowObject borrowObject} and {@link #returnObject returnObject}.</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> * </em><a name="29" href="#29">29</a> <em> * <font color="#0000CC">try</font> {</em><a name="30" href="#30">30</a> <em> * obj = pool.borrowObject();</em><a name="31" href="#31">31</a> <em> * <font color="#00CC00">//...use the object...</font></em><a name="32" href="#32">32</a> <em> * } <font color="#0000CC">catch</font>(Exception e) {</em><a name="33" href="#33">33</a> <em> * <font color="#00CC00">//...handle any exceptions...</font></em><a name="34" href="#34">34</a> <em> * } <font color="#0000CC">finally</font> {</em><a name="35" href="#35">35</a> <em> * <font color="#00CC00">// make sure the object is returned to the pool</font></em><a name="36" href="#36">36</a> <em> * <font color="#0000CC">if</font>(<font color="#0000CC">null</font> != obj) {</em><a name="37" href="#37">37</a> <em> * pool.returnObject(obj);</em><a name="38" href="#38">38</a> <em> * }</em><a name="39" href="#39">39</a> <em> * }</pre></td></tr></table></em><a name="40" href="#40">40</a> <em> * See {@link org.apache.commons.pool.BaseObjectPool BaseObjectPool} for a simple base implementation.</em><a name="41" href="#41">41</a> <em> *</em><a name="42" href="#42">42</a> <em> * @author Rodney Waldhoff</em><a name="43" href="#43">43</a> <em> * @version $Revision: 155430 $ $Date: 2005-02-26 08:13:28 -0500 (Sat, 26 Feb 2005) $ </em><a name="44" href="#44">44</a> <em> *</em><a name="45" href="#45">45</a> <em> */</em><a name="46" href="#46">46</a> <strong>public</strong> <strong>interface</strong> <a href="../../../../org/apache/commons/pool/ObjectPool.html">ObjectPool</a> {<a name="47" href="#47">47</a> <em>/**<em>*</em></em><a name="48" href="#48">48</a> <em> * Obtain an instance from my pool.</em><a name="49" href="#49">49</a> <em> * By contract, clients MUST return</em><a name="50" href="#50">50</a> <em> * the borrowed instance using</em><a name="51" href="#51">51</a> <em> * {@link #returnObject(java.lang.Object) returnObject}</em><a name="52" href="#52">52</a> <em> * or a related method as defined in an implementation</em><a name="53" href="#53">53</a> <em> * or sub-interface.</em><a name="54" href="#54">54</a> <em> * <p></em><a name="55" href="#55">55</a> <em> * The behaviour of this method when the pool has been exhausted</em><a name="56" href="#56">56</a> <em> * is not specified (although it may be specified by implementations).</em><a name="57" href="#57">57</a> <em> *</em><a name="58" href="#58">58</a> <em> * @return an instance from my pool.</em><a name="59" href="#59">59</a> <em> */</em><a name="60" href="#60">60</a> Object borrowObject() throws Exception;<a name="61" href="#61">61</a> <a name="62" href="#62">62</a> <em>/**<em>*</em></em><a name="63" href="#63">63</a> <em> * Return an instance to my pool.</em><a name="64" href="#64">64</a> <em> * By contract, <i>obj</i> MUST have been obtained</em><a name="65" href="#65">65</a> <em> * using {@link #borrowObject() borrowObject}</em><a name="66" href="#66">66</a> <em> * or a related method as defined in an implementation</em><a name="67" href="#67">67</a> <em> * or sub-interface.</em><a name="68" href="#68">68</a> <em> *</em><a name="69" href="#69">69</a> <em> * @param obj a {@link #borrowObject borrowed} instance to be returned.</em><a name="70" href="#70">70</a> <em> */</em><a name="71" href="#71">71</a> <strong>void</strong> returnObject(Object obj) 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> * Invalidates an object from the 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() borrowObject}</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> * <p></em><a name="80" href="#80">80</a> <em> * This method should be used when an object that has been borrowed</em><a name="81" href="#81">81</a> <em> * is determined (due to an exception or other problem) to be invalid.</em><a name="82" href="#82">82</a> <em> * If the connection should be validated before or after borrowing,</em><a name="83" href="#83">83</a> <em> * then the {@link PoolableObjectFactory#validateObject} method should be</em><a name="84" href="#84">84</a> <em> * used instead.</em><a name="85" href="#85">85</a> <em> *</em><a name="86" href="#86">86</a> <em> * @param obj a {@link #borrowObject borrowed} instance to be returned.</em><a name="87" href="#87">87</a> <em> */</em><a name="88" href="#88">88</a> <strong>void</strong> invalidateObject(Object obj) throws Exception;<a name="89" href="#89">89</a> <a name="90" href="#90">90</a> <em>/**<em>*</em></em><a name="91" href="#91">91</a> <em> * Create an object using my {@link #setFactory factory} or other</em><a name="92" href="#92">92</a> <em> * implementation dependent mechanism, and place it into the pool.</em><a name="93" href="#93">93</a> <em> * addObject() is useful for "pre-loading" a pool with idle objects.</em><a name="94" href="#94">94</a> <em> * (Optional operation).</em><a name="95" href="#95">95</a> <em> */</em><a name="96" href="#96">96</a> <strong>void</strong> addObject() throws Exception;<a name="97" href="#97">97</a> <a name="98" href="#98">98</a> <em>/**<em>*</em></em><a name="99" href="#99">99</a> <em> * Return the number of instances</em><a name="100" href="#100">100</a> <em> * currently idle in my pool (optional operation). </em><a name="101" href="#101">101</a> <em> * This may be considered an approximation of the number</em><a name="102" href="#102">102</a> <em> * of objects that can be {@link #borrowObject borrowed}</em><a name="103" href="#103">103</a> <em> * without creating any new instances.</em><a name="104" href="#104">104</a> <em> *</em><a name="105" href="#105">105</a> <em> * @return the number of instances currently idle in my pool</em><a name="106" href="#106">106</a> <em> * @throws UnsupportedOperationException if this implementation does not support the operation</em><a name="107" href="#107">107</a> <em> */</em><a name="108" href="#108">108</a> <strong>int</strong> getNumIdle() throws UnsupportedOperationException;<a name="109" href="#109">109</a> <a name="110" href="#110">110</a> <em>/**<em>*</em></em><a name="111" href="#111">111</a> <em> * Return the number of instances</em><a name="112" href="#112">112</a> <em> * currently borrowed from my pool </em><a name="113" href="#113">113</a> <em> * (optional operation).</em><a name="114" href="#114">114</a> <em> *</em><a name="115" href="#115">115</a> <em> * @return the number of instances currently borrowed in my pool</em><a name="116" href="#116">116</a> <em> * @throws UnsupportedOperationException if this implementation does not support the operation</em><a name="117" href="#117">117</a> <em> */</em><a name="118" href="#118">118</a> <strong>int</strong> getNumActive() throws UnsupportedOperationException;<a name="119" href="#119">119</a> <a name="120" href="#120">120</a> <em>/**<em>*</em></em><a name="121" href="#121">121</a> <em> * Clears any objects sitting idle in the pool, releasing any</em><a name="122" href="#122">122</a> <em> * associated resources (optional operation).</em><a name="123" href="#123">123</a> <em> *</em><a name="124" href="#124">124</a> <em> * @throws UnsupportedOperationException if this implementation does not support the operation</em><a name="125" href="#125">125</a> <em> */</em><a name="126" href="#126">126</a> <strong>void</strong> clear() throws Exception, UnsupportedOperationException;<a name="127" href="#127">127</a> <a name="128" href="#128">128</a> <em>/**<em>*</em></em><a name="129" href="#129">129</a> <em> * Close this pool, and free any resources associated with it.</em><a name="130" href="#130">130</a> <em> */</em><a name="131" href="#131">131</a> <strong>void</strong> close() throws Exception;<a name="132" href="#132">132</a> <a name="133" href="#133">133</a> <em>/**<em>*</em></em><a name="134" href="#134">134</a> <em> * Sets the {@link PoolableObjectFactory factory} I use</em><a name="135" href="#135">135</a> <em> * to create new instances (optional operation).</em><a name="136" href="#136">136</a> <em> * @param factory the {@link PoolableObjectFactory} I use to create new instances.</em><a name="137" href="#137">137</a> <em> *</em><a name="138" href="#138">138</a> <em> * @throws IllegalStateException when the factory cannot be set at this time</em><a name="139" href="#139">139</a> <em> * @throws UnsupportedOperationException if this implementation does not support the operation</em><a name="140" href="#140">140</a> <em> */</em><a name="141" href="#141">141</a> <strong>void</strong> setFactory(<a href="../../../../org/apache/commons/pool/PoolableObjectFactory.html">PoolableObjectFactory</a> factory) throws IllegalStateException, UnsupportedOperationException;<a name="142" href="#142">142</a> }</pre><hr/><div id="footer">This page was automatically generated by <a href="http://maven.apache.org/">Maven</a></div></body></html>⌨️ 快捷键说明
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