uTools-Manuals/docs/java/javax/management/openmbean/CompositeDataView.html

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     javax.management.openmbean 
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<h2 class="title" title="Interface CompositeDataView">Interface CompositeDataView</h2>
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<hr/> <br/> <pre>public interface <span class="typeNameLabel">CompositeDataView</span></pre>
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<p> <span>一个Java类可以实现此接口，以表明它是如何被转化为<code>CompositeData</code>通过MXBean框架。</span> </p>
<p> <span>使用此类的一个典型方法是除了在MXBean框架提供的<code>CompositeType</code>中声明的内容外，还可以向<code>CompositeData</code>添加额外的项目。</span> <span>为此，您必须创建另一个<code>CompositeType</code>具有所有相同的项目，加上额外的项目。</span> </p>
<p> <span>例如，假设你有一个类<code>Measure</code> ，它由一个叫做<code>units</code>的字符串和一个<code>value</code> ，它是一个<code>long</code>或一个<code>double</code> 。</span> <span>它可能看起来像这样：</span> </p>
<pre>  <span>public class Measure implements CompositeDataView {
     private String units;
     private Number value; // a Long or a Double

     public Measure(String units, Number value) {
         this.units = units;
         this.value = value;
     }

     public static Measure from(CompositeData cd) {
         return new Measure((String) cd.get("units"),
                            (Number) cd.get("value"));
     }

     public String getUnits() {
         return units;
     }

     // Can't be called getValue(), because Number is not a valid type
     // in an MXBean, so the implied "value" property would be rejected.
     public Number _getValue() {
         return value;
     }

     public CompositeData toCompositeData(CompositeType ct) {
         try {
             <code> List&lt;String&gt; itemNames = new ArrayList&lt;String&gt;(ct.keySet());</code>
             <code> List&lt;String&gt; itemDescriptions = new ArrayList&lt;String&gt;();</code>
             <code> List&lt;OpenType&lt;?&gt;&gt; itemTypes = new ArrayList&lt;OpenType&lt;?&gt;&gt;();</code>
             for (String item : itemNames) {
                 itemDescriptions.add(ct.getDescription(item));
                 itemTypes.add(ct.getType(item));
             }
             itemNames.add("value");
             itemDescriptions.add("long or double value of the measure");
             itemTypes.add((value instanceof Long) ? SimpleType.LONG :
                           SimpleType.DOUBLE);
             CompositeType xct =
                 new CompositeType(ct.getTypeName(),
                                   ct.getDescription(),
                                   itemNames.toArray(new String[0]),
                                   itemDescriptions.toArray(new String[0]),
                                   itemTypes.toArray(new OpenType&lt;?&gt;[0]));
             CompositeData cd =
                 new CompositeDataSupport(xct,
                                          new String[] {"units", "value"},
                                          new Object[] {units, value});
             assert ct.isValue(cd);  // check we've done it right
             return cd;
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
     }
 }</span> </pre>
<p> <span>该<code>CompositeType</code>将出现在<code>openType</code>的领域<a href="../../../javax/management/Descriptor.html" title="javax.management中的接口"><code>Descriptor</code></a>这种类型的属性或操作中，只显示<code>units</code>项目，但实际<code>CompositeData</code>所产生将同时拥有<code>units</code>和<code>value</code> 。</span> </p>
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<span class="simpleTagLabel">从以下版本开始：</span>
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<dd>
         1.6 
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<span class="seeLabel">另请参见：</span>
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<span><a href="../../../javax/management/MXBean.html" title="javax.management中的注释"><code>MXBean</code></a></span>
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<!-- --> </a> <h3>方法摘要</h3>
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<span class="activeTableTab" id="t0"><span>所有方法</span><span class="tabEnd"> </span></span>
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<span class="tableTab" id="t3"><span><a href="javascript:show(4);">抽象方法</a></span><span class="tabEnd"> </span></span>
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<th class="colLast" scope="col">Method and Description</th>
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<td class="colFirst"><code><a href="../../../javax/management/openmbean/CompositeData.html" title="interface in javax.management.openmbean">CompositeData</a></code></td>
<td class="colLast"><code><span class="memberNameLink"><a href="../../../javax/management/openmbean/CompositeDataView.html#toCompositeData-javax.management.openmbean.CompositeType-">toCompositeData</a></span>(<a href="../../../javax/management/openmbean/CompositeType.html" title="class in javax.management.openmbean">CompositeType</a> ct)</code>
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              返回一个对应于该对象中的值的 
             <code>CompositeData</code> 。 
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<li class="blockList"> <h4>toCompositeData</h4> <pre><a href="../../../javax/management/openmbean/CompositeData.html" title="interface in javax.management.openmbean">CompositeData</a> toCompositeData(<a href="../../../javax/management/openmbean/CompositeType.html" title="class in javax.management.openmbean">CompositeType</a> ct)</pre>
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<p> <span>返回一个对应于该对象中的值的<code>CompositeData</code> 。</span> <span>返回的值通常应的一个实例<a href="../../../javax/management/openmbean/CompositeDataSupport.html" title="javax.management.openmbean中的类"><code>CompositeDataSupport</code></a> ，或序列化作为一类<code>CompositeDataSupport</code>经由<code>writeReplace</code>方法。</span> <span>否则，接收对象的远程客户端可能无法重构。</span> </p>
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<span class="paramLabel">参数</span>
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<span><code>ct</code> - 预期的<code>CompositeType</code>的返回值。</span>
<span>如果返回值为<code>cd</code> ，那么<code>cd.getCompositeType().equals(ct)</code>应为true。</span>
<span>通常这是因为<code>cd</code>是一个<a href="../../../javax/management/openmbean/CompositeDataSupport.html" title="javax.management.openmbean中的类"><code>CompositeDataSupport</code></a>构造的<code>ct</code>作为其<code>CompositeType</code> 。</span>
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<span class="returnLabel">结果</span>
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             the 
            <code>CompositeData</code>. 
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