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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>StackObjectPool xref</title><link type="text/css" rel="stylesheet" href="../../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../../apidocs/org/apache/commons/pool/impl/StackObjectPool.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/impl/package-summary.html">org.apache.commons.pool.impl</a>;<a name="18" href="#18">18</a> <a name="19" href="#19">19</a> <strong>import</strong> java.util.Iterator;<a name="20" href="#20">20</a> <strong>import</strong> java.util.NoSuchElementException;<a name="21" href="#21">21</a> <strong>import</strong> java.util.Stack;<a name="22" href="#22">22</a> <a name="23" href="#23">23</a> <strong>import</strong> org.apache.commons.pool.BaseObjectPool;<a name="24" href="#24">24</a> <strong>import</strong> org.apache.commons.pool.ObjectPool;<a name="25" href="#25">25</a> <strong>import</strong> org.apache.commons.pool.PoolableObjectFactory;<a name="26" href="#26">26</a> <a name="27" href="#27">27</a> <em>/**<em>*</em></em><a name="28" href="#28">28</a> <em> * A simple, {@link java.util.Stack Stack}-based {@link ObjectPool} implementation.</em><a name="29" href="#29">29</a> <em> * <p></em><a name="30" href="#30">30</a> <em> * Given a {@link PoolableObjectFactory}, this class will maintain</em><a name="31" href="#31">31</a> <em> * a simple pool of instances. A finite number of "sleeping"</em><a name="32" href="#32">32</a> <em> * or idle instances is enforced, but when the pool is</em><a name="33" href="#33">33</a> <em> * empty, new instances are created to support the new load.</em><a name="34" href="#34">34</a> <em> * Hence this class places no limit on the number of "active"</em><a name="35" href="#35">35</a> <em> * instances created by the pool, but is quite useful for</em><a name="36" href="#36">36</a> <em> * re-using <tt>Object</tt>s without introducing</em><a name="37" href="#37">37</a> <em> * artificial limits.</em><a name="38" href="#38">38</a> <em> *</em><a name="39" href="#39">39</a> <em> * @author Rodney Waldhoff</em><a name="40" href="#40">40</a> <em> * @author Dirk Verbeeck</em><a name="41" href="#41">41</a> <em> * @version $Revision: 383290 $ $Date: 2006-03-05 02:00:15 -0500 (Sun, 05 Mar 2006) $</em><a name="42" href="#42">42</a> <em> */</em><a name="43" href="#43">43</a> <strong>public</strong> <strong>class</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a> <strong>extends</strong> <a href="../../../../../org/apache/commons/pool/BaseObjectPool.html">BaseObjectPool</a> implements <a href="../../../../../org/apache/commons/pool/ObjectPool.html">ObjectPool</a> {<a name="44" href="#44">44</a> <em>/**<em>*</em></em><a name="45" href="#45">45</a> <em> * Create a new pool using</em><a name="46" href="#46">46</a> <em> * no factory. Clients must first populate the pool</em><a name="47" href="#47">47</a> <em> * using {@link #returnObject(java.lang.Object)}</em><a name="48" href="#48">48</a> <em> * before they can be {@link #borrowObject borrowed}.</em><a name="49" href="#49">49</a> <em> */</em><a name="50" href="#50">50</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>() {<a name="51" href="#51">51</a> <strong>this</strong>((PoolableObjectFactory)<strong>null</strong>,DEFAULT_MAX_SLEEPING,DEFAULT_INIT_SLEEPING_CAPACITY);<a name="52" href="#52">52</a> }<a name="53" href="#53">53</a> <a name="54" href="#54">54</a> <em>/**<em>*</em></em><a name="55" href="#55">55</a> <em> * Create a new pool using</em><a name="56" href="#56">56</a> <em> * no factory. Clients must first populate the pool</em><a name="57" href="#57">57</a> <em> * using {@link #returnObject(java.lang.Object)}</em><a name="58" href="#58">58</a> <em> * before they can be {@link #borrowObject borrowed}.</em><a name="59" href="#59">59</a> <em> *</em><a name="60" href="#60">60</a> <em> * @param maxIdle cap on the number of "sleeping" instances in the pool</em><a name="61" href="#61">61</a> <em> */</em><a name="62" href="#62">62</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>(<strong>int</strong> maxIdle) {<a name="63" href="#63">63</a> <strong>this</strong>((PoolableObjectFactory)<strong>null</strong>,maxIdle,DEFAULT_INIT_SLEEPING_CAPACITY);<a name="64" href="#64">64</a> }<a name="65" href="#65">65</a> <a name="66" href="#66">66</a> <em>/**<em>*</em></em><a name="67" href="#67">67</a> <em> * Create a new pool using</em><a name="68" href="#68">68</a> <em> * no factory. Clients must first populate the pool</em><a name="69" href="#69">69</a> <em> * using {@link #returnObject(java.lang.Object)}</em><a name="70" href="#70">70</a> <em> * before they can be {@link #borrowObject borrowed}.</em><a name="71" href="#71">71</a> <em> *</em><a name="72" href="#72">72</a> <em> * @param maxIdle cap on the number of "sleeping" instances in the pool</em><a name="73" href="#73">73</a> <em> * @param initIdleCapacity initial size of the pool (this specifies the size of the container,</em><a name="74" href="#74">74</a> <em> * it does not cause the pool to be pre-populated.)</em><a name="75" href="#75">75</a> <em> */</em><a name="76" href="#76">76</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>(<strong>int</strong> maxIdle, <strong>int</strong> initIdleCapacity) {<a name="77" href="#77">77</a> <strong>this</strong>((PoolableObjectFactory)<strong>null</strong>,maxIdle,initIdleCapacity);<a name="78" href="#78">78</a> }<a name="79" href="#79">79</a> <a name="80" href="#80">80</a> <em>/**<em>*</em></em><a name="81" href="#81">81</a> <em> * Create a new <tt>StackObjectPool</tt> using</em><a name="82" href="#82">82</a> <em> * the specified <i>factory</i> to create new instances.</em><a name="83" href="#83">83</a> <em> *</em><a name="84" href="#84">84</a> <em> * @param factory the {@link PoolableObjectFactory} used to populate the pool</em><a name="85" href="#85">85</a> <em> */</em><a name="86" href="#86">86</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>(<a href="../../../../../org/apache/commons/pool/PoolableObjectFactory.html">PoolableObjectFactory</a> factory) {<a name="87" href="#87">87</a> <strong>this</strong>(factory,DEFAULT_MAX_SLEEPING,DEFAULT_INIT_SLEEPING_CAPACITY);<a name="88" href="#88">88</a> }<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 a new <tt>SimpleObjectPool</tt> using</em><a name="92" href="#92">92</a> <em> * the specified <i>factory</i> to create new instances,</em><a name="93" href="#93">93</a> <em> * capping the number of "sleeping" instances to <i>max</i>.</em><a name="94" href="#94">94</a> <em> *</em><a name="95" href="#95">95</a> <em> * @param factory the {@link PoolableObjectFactory} used to populate the pool</em><a name="96" href="#96">96</a> <em> * @param maxIdle cap on the number of "sleeping" instances in the pool</em><a name="97" href="#97">97</a> <em> */</em><a name="98" href="#98">98</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>(<a href="../../../../../org/apache/commons/pool/PoolableObjectFactory.html">PoolableObjectFactory</a> factory, <strong>int</strong> maxIdle) {<a name="99" href="#99">99</a> <strong>this</strong>(factory,maxIdle,DEFAULT_INIT_SLEEPING_CAPACITY);<a name="100" href="#100">100</a> }<a name="101" href="#101">101</a> <a name="102" href="#102">102</a> <em>/**<em>*</em></em><a name="103" href="#103">103</a> <em> * Create a new <tt>SimpleObjectPool</tt> using</em><a name="104" href="#104">104</a> <em> * the specified <i>factory</i> to create new instances,</em><a name="105" href="#105">105</a> <em> * capping the number of "sleeping" instances to <i>max</i>,</em><a name="106" href="#106">106</a> <em> * and initially allocating a container capable of containing</em><a name="107" href="#107">107</a> <em> * at least <i>init</i> instances.</em><a name="108" href="#108">108</a> <em> *</em><a name="109" href="#109">109</a> <em> * @param factory the {@link PoolableObjectFactory} used to populate the pool</em><a name="110" href="#110">110</a> <em> * @param maxIdle cap on the number of "sleeping" instances in the pool</em><a name="111" href="#111">111</a> <em> * @param initIdleCapacity initial size of the pool (this specifies the size of the container,</em><a name="112" href="#112">112</a> <em> * it does not cause the pool to be pre-populated.)</em><a name="113" href="#113">113</a> <em> */</em><a name="114" href="#114">114</a> <strong>public</strong> <a href="../../../../../org/apache/commons/pool/impl/StackObjectPool.html">StackObjectPool</a>(<a href="../../../../../org/apache/commons/pool/PoolableObjectFactory.html">PoolableObjectFactory</a> factory, <strong>int</strong> maxIdle, <strong>int</strong> initIdleCapacity) {<a name="115" href="#115">115</a> _factory = factory;<a name="116" href="#116">116</a> _maxSleeping = (maxIdle < 0 ? DEFAULT_MAX_SLEEPING : maxIdle);<a name="117" href="#117">117</a> <strong>int</strong> initcapacity = (initIdleCapacity < 1 ? DEFAULT_INIT_SLEEPING_CAPACITY : initIdleCapacity);<a name="118" href="#118">118</a> _pool = <strong>new</strong> Stack();<a name="119" href="#119">119</a> _pool.ensureCapacity( initcapacity > _maxSleeping ? _maxSleeping : initcapacity);<a name="120" href="#120">120</a> }<a name="121" href="#121">121</a> <a name="122" href="#122">122</a> <strong>public</strong> <strong>synchronized</strong> Object borrowObject() throws Exception {<a name="123" href="#123">123</a> assertOpen();<a name="124" href="#124">124</a> Object obj = <strong>null</strong>;<a name="125" href="#125">125</a> <strong>while</strong> (<strong>null</strong> == obj) {<a name="126" href="#126">126</a> <strong>if</strong> (!_pool.empty()) {<a name="127" href="#127">127</a> obj = _pool.pop();<a name="128" href="#128">128</a> } <strong>else</strong> {<a name="129" href="#129">129</a> <strong>if</strong>(<strong>null</strong> == _factory) {<a name="130" href="#130">130</a> <strong>throw</strong> <strong>new</strong> NoSuchElementException();<a name="131" href="#131">131</a> } <strong>else</strong> {<a name="132" href="#132">132</a> obj = _factory.makeObject();<a name="133" href="#133">133</a> }⌨️ 快捷键说明
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