📄 expressionevaluator.html
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<a name="1" href="#1">1</a> <strong>package</strong> net.sf.navigator.taglib.el;
<a name="2" href="#2">2</a>
<a name="3" href="#3">3</a> <strong>import</strong> org.apache.taglibs.standard.lang.support.ExpressionEvaluatorManager;
<a name="4" href="#4">4</a>
<a name="5" href="#5">5</a> <strong>import</strong> javax.servlet.jsp.JspException;
<a name="6" href="#6">6</a> <strong>import</strong> javax.servlet.jsp.PageContext;
<a name="7" href="#7">7</a> <strong>import</strong> javax.servlet.jsp.tagext.Tag;
<a name="8" href="#8">8</a>
<a name="9" href="#9">9</a>
<a name="10" href="#10">10</a> <em>/**</em>
<a name="11" href="#11">11</a> <em> * Utility class to help with the evaluation of JSTL Expression Language. It</em>
<a name="12" href="#12">12</a> <em> * mainly encapsulates the calls to ExpressionEvaluationManager to ease the</em>
<a name="13" href="#13">13</a> <em> * use of this class.</em>
<a name="14" href="#14">14</a> <em> */</em>
<a name="15" href="#15">15</a> <strong>public</strong> <strong>class</strong> <a href="../../../../../net/sf/navigator/taglib/el/ExpressionEvaluator.html">ExpressionEvaluator</a> {
<a name="16" href="#16">16</a> <em class="comment">//~ Instance fields ========================================================</em>
<a name="17" href="#17">17</a>
<a name="18" href="#18">18</a> <strong>private</strong> PageContext context;
<a name="19" href="#19">19</a> <strong>private</strong> Tag tag;
<a name="20" href="#20">20</a>
<a name="21" href="#21">21</a> <em class="comment">//~ Constructors ===========================================================</em>
<a name="22" href="#22">22</a>
<a name="23" href="#23">23</a> <strong>public</strong> <a href="../../../../../net/sf/navigator/taglib/el/ExpressionEvaluator.html">ExpressionEvaluator</a>(Tag tag, PageContext context) {
<a name="24" href="#24">24</a> <strong>this</strong>.tag = tag;
<a name="25" href="#25">25</a> <strong>this</strong>.context = context;
<a name="26" href="#26">26</a> }
<a name="27" href="#27">27</a>
<a name="28" href="#28">28</a> <em class="comment">//~ Methods ================================================================</em>
<a name="29" href="#29">29</a>
<a name="30" href="#30">30</a> <em>/**</em>
<a name="31" href="#31">31</a> <em> * Evaluate expression in attrValue.</em>
<a name="32" href="#32">32</a> <em> *</em>
<a name="33" href="#33">33</a> <em> * @return evaluate expression of attrValue, null if attrValue is null.</em>
<a name="34" href="#34">34</a> <em> */</em>
<a name="35" href="#35">35</a> <strong>public</strong> Object eval(String attrName, String attrValue, Class returnClass)
<a name="36" href="#36">36</a> throws JspException {
<a name="37" href="#37">37</a> Object result = <strong>null</strong>;
<a name="38" href="#38">38</a>
<a name="39" href="#39">39</a> <strong>if</strong> (attrValue != <strong>null</strong>) {
<a name="40" href="#40">40</a> result =
<a name="41" href="#41">41</a> ExpressionEvaluatorManager.evaluate(attrName, attrValue,
<a name="42" href="#42">42</a> returnClass, tag, context);
<a name="43" href="#43">43</a> }
<a name="44" href="#44">44</a>
<a name="45" href="#45">45</a> <strong>return</strong> result;
<a name="46" href="#46">46</a> }
<a name="47" href="#47">47</a>
<a name="48" href="#48">48</a> <strong>public</strong> String evalString(String attrName, String attrValue)
<a name="49" href="#49">49</a> throws JspException {
<a name="50" href="#50">50</a> <strong>return</strong> (String) eval(attrName, attrValue, String.<strong>class</strong>);
<a name="51" href="#51">51</a> }
<a name="52" href="#52">52</a>
<a name="53" href="#53">53</a> <strong>public</strong> <strong>boolean</strong> evalBoolean(String attrName, String attrValue)
<a name="54" href="#54">54</a> throws JspException {
<a name="55" href="#55">55</a> Boolean rtn = (Boolean) eval(attrName, attrValue, Boolean.<strong>class</strong>);
<a name="56" href="#56">56</a>
<a name="57" href="#57">57</a> <strong>if</strong> (rtn != <strong>null</strong>) {
<a name="58" href="#58">58</a> <strong>return</strong> rtn.booleanValue();
<a name="59" href="#59">59</a> } <strong>else</strong> {
<a name="60" href="#60">60</a> <strong>return</strong> false;
<a name="61" href="#61">61</a> }
<a name="62" href="#62">62</a> }
<a name="63" href="#63">63</a>
<a name="64" href="#64">64</a> <strong>public</strong> <strong>long</strong> evalLong(String attrName, String attrValue)
<a name="65" href="#65">65</a> throws JspException {
<a name="66" href="#66">66</a> Long rtn = (Long) eval(attrName, attrValue, Long.<strong>class</strong>);
<a name="67" href="#67">67</a>
<a name="68" href="#68">68</a> <strong>if</strong> (rtn != <strong>null</strong>) {
<a name="69" href="#69">69</a> <strong>return</strong> rtn.longValue();
<a name="70" href="#70">70</a> } <strong>else</strong> {
<a name="71" href="#71">71</a> <strong>return</strong> -1L;
<a name="72" href="#72">72</a> }
<a name="73" href="#73">73</a> }
<a name="74" href="#74">74</a>
<a name="75" href="#75">75</a> <strong>public</strong> <strong>int</strong> evalInt(String attrName, String attrValue)
<a name="76" href="#76">76</a> throws JspException {
<a name="77" href="#77">77</a> Integer rtn = (Integer) eval(attrName, attrValue, Integer.<strong>class</strong>);
<a name="78" href="#78">78</a>
<a name="79" href="#79">79</a> <strong>if</strong> (rtn != <strong>null</strong>) {
<a name="80" href="#80">80</a> <strong>return</strong> rtn.intValue();
<a name="81" href="#81">81</a> } <strong>else</strong> {
<a name="82" href="#82">82</a> <strong>return</strong> -1;
<a name="83" href="#83">83</a> }
<a name="84" href="#84">84</a> }
<a name="85" href="#85">85</a> }
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