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3 分钟 读完 (大约 501 个字)
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<h1 class="title is-size-3 is-size-4-mobile has-text-weight-normal">
一起学java之Java中的反射机制简介
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<h4 id="概述"><a href="#概述" class="headerlink" title="概述"></a>概述</h4><p>Reflection,反射,在java中指的是我们可以于运行时加载,探知,使用编译期间完全未知的类,包括实例化对象,唤醒其方法,对其fields设值等 </p>
<a id="more"></a>
<h4 id="Class类"><a href="#Class类" class="headerlink" title="Class类"></a>Class类</h4><p>1.在java中,万物皆对象,java中的类是为了描述对象,包括:类名,属性,方法等类结构,java中把类的描述也定义为类,该类比较特殊,名称是Class.每一个类在加载时,虚拟机都会根据加载的类创建对应的Class对象,放在内存的程序区,Class对象是具体类的描述,包括具体类的类名,方法,属性,构造方法等。 </p>
<p>2.理解Class类 </p>
<p><img src="/images/20191025150322.png" alt></p>
<h4 id="Class类的应用"><a href="#Class类的应用" class="headerlink" title="Class类的应用"></a>Class类的应用</h4><p>1.如何加载类 </p>
<ul>
<li>在第一次使用类时会加载类，（声明类的变量或new类的对象） </li>
<li>主动加载（类名.class 或 Class.forName(“类名”)） </li>
<li>Class对象一旦加载成功，在程序运行结束之前，Class对象永远存储在程序区，直到应用程序结束 </li>
<li>一个类只加载一次，重复加载则无效 </li>
<li>举例： </li>
</ul>
<p><img src="/images/20191025150425.png" alt></p>
<p>2.如何得到一个类的Class对象 </p>
<ul>
<li>对象名.class </li>
<li>类名.class </li>
<li>Class.forName(“类名”) </li>
<li>举例 </li>
</ul>
<p><img src="/images/20191025150540.png" alt></p>
<p>3.如何获得一个类有哪些属性 </p>
<table>
<thead>
<tr>
<th>方法名称</th>
<th>说明</th>
</tr>
</thead>
<tbody><tr>
<td>Field[] getFields()</td>
<td>得到类的公共属性</td>
</tr>
<tr>
<td>Field[] getDeclaredFields()</td>
<td>得到声明的字段</td>
</tr>
<tr>
<td>Field getField(String )</td>
<td>得到对应的字段,必须是公共的</td>
</tr>
<tr>
<td>…</td>
<td>…</td>
</tr>
</tbody></table>
<ul>
<li>举例 </li>
</ul>
<p><img src="/images/20191025150822.png" alt></p>
<p>4.如何获得一个类有哪些方法 </p>
<ul>
<li>常用方法 </li>
</ul>
<table>
<thead>
<tr>
<th>方法名称</th>
<th>说明</th>
</tr>
</thead>
<tbody><tr>
<td>Method[] getMethods()</td>
<td>得到类的公共方法，包括父类的</td>
</tr>
<tr>
<td>Method[] getDeclaredMethods()</td>
<td>得到声明的方法，不包括父类的</td>
</tr>
<tr>
<td>Method getMethod(String，…Class )</td>
<td>得到对应的方法</td>
</tr>
<tr>
<td>…</td>
<td>…</td>
</tr>
</tbody></table>
<ul>
<li>举例 </li>
</ul>
<p><img src="/images/20191025151107.png" alt></p>
<p>5.如何产生一个类的对象 </p>
<ul>
<li>使用newInstance()方法 </li>
<li>举例 </li>
</ul>
<p><img src="/images/20191025151158.png" alt></p>
<p>6.如何使用类的属性，赋值和取值 </p>
<ul>
<li>举例 </li>
</ul>
<p><img src="/images/20191025151250.png" alt></p>
<p>7.如何使用类的方法，调用方法 </p>
<ul>
<li>Invoke()方法 </li>
<li>举例 </li>
</ul>
<p><img src="/images/20191025151351.png" alt></p>
</div>
<ul class="post-copyright">
<li><strong>本文标题：</strong><a href="https://blog.visutech.cn/2909453862.html">一起学java之Java中的反射机制简介</a></li>
<li><strong>本文作者：</strong><a href="https://blog.visutech.cn">程振奇 | smallodd</a></li>
<li><strong>本文链接：</strong><a href="https://blog.visutech.cn/2909453862.html">https://blog.visutech.cn/2909453862.html</a></li>
<li><strong>发布时间：</strong>2013-07-25</li>
<li><strong>版权声明：</strong>本博客所有文章除特别声明外，均采用 <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/deed.zh" rel="external nofollow" target="_blank">CC BY-NC-SA 4.0</a> 许可协议。转载请注明出处！
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