Netty框架SimpleChannelInboundHandler<T>主要方法详解

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
* 覆盖了 channelRead0() 事件处理方法。
* 每当从服务端读到客户端写入信息时，
* 其中如果你使用的是 Netty 5.x 版本时，
* 需要把 channelRead0() 重命名为messageReceived()
*/</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">channelRead0</span>(ChannelHandlerContext arg0, String arg1)
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Exception {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO Auto-generated method stub</span>

}

<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
* 覆盖channelActive 方法在channel被启用的时候触发（在建立连接的时候）
* 覆盖了 channelActive() 事件处理方法。服务端监听到客户端活动
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">channelActive</span>(ChannelHandlerContext ctx) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Exception {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO Auto-generated method stub</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.channelActive(ctx);
}

<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
* (non-Javadoc)
* 覆盖了 handlerAdded() 事件处理方法。
* 每当从服务端收到新的客户端连接时
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">handlerAdded</span>(ChannelHandlerContext ctx) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Exception {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO Auto-generated method stub</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.handlerAdded(ctx);
}

<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
* (non-Javadoc)
* .覆盖了 handlerRemoved() 事件处理方法。
* 每当从服务端收到客户端断开时
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">handlerRemoved</span>(ChannelHandlerContext ctx) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Exception {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO Auto-generated method stub</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.handlerRemoved(ctx);
}

<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
* exceptionCaught() 事件处理方法是当出现 Throwable 对象才会被调用，
* 即当 Netty 由于 IO 错误或者处理器在处理事件时抛出的异常时。
* 在大部分情况下，捕获的异常应该被记录下来并且把关联的 channel 给关闭掉。
* 然而这个方法的处理方式会在遇到不同异常的情况下有不同的实现，
* 比如你可能想在关闭连接之前发送一个错误码的响应消息。
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">exceptionCaught</span>(ChannelHandlerContext ctx, Throwable cause)
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Exception {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO Auto-generated method stub</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.exceptionCaught(ctx, cause);
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li&g
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