<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have searched the <a href="https://github.com/apache/dubbo/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/apache/dubbo/blob/master/FAQ.md">FAQ</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h3 dir="auto">Environment</h3>
<ul dir="auto">
<li>Dubbo version: xxx</li>
<li>Operating System version: xxx</li>
<li>Java version: xxx</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<p dir="auto">remove the explicit type when assigning object<br>
<a href="https://github.com/apache/dubbo/blob/master/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryProtocol.java#L532">https://github.com/apache/dubbo/blob/master/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryProtocol.java#L532</a></p>
<p dir="auto"><a href="https://github.com/apache/dubbo/blob/master/dubbo-rpc/dubbo-rpc-api/src/main/java/org/apache/dubbo/rpc/RpcInvocation.java#L72">https://github.com/apache/dubbo/blob/master/dubbo-rpc/dubbo-rpc-api/src/main/java/org/apache/dubbo/rpc/RpcInvocation.java#L72</a></p>
<p dir="auto">camel case:<br>
</p><div class="Box Box--condensed my-2">
  <div class="Box-header f6">
    <p class="mb-0 text-bold">
      <a href="https://github.com/apache/dubbo/blob/ba89f44f5aeddd2d06024232a15e355c2e8dc5cd/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java#L299">dubbo/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java</a>
    </p>
    <p class="mb-0 color-fg-muted">
         Line 299
      in
      <a data-pjax="true" class="commit-tease-sha" href="/apache/dubbo/commit/ba89f44f5aeddd2d06024232a15e355c2e8dc5cd">ba89f44</a>
    </p>
  </div>
  <div itemprop="text" class="Box-body p-0 blob-wrapper blob-wrapper-embedded data">
    <table class="highlight tab-size mb-0 js-file-line-container" data-tab-size="8" data-paste-markdown-skip="">

        <tbody><tr class="border-0">
          <td id="L299" class="blob-num border-0 px-3 py-0 color-bg-default" data-line-number="299"></td>
          <td id="LC299" class="blob-code border-0 px-3 py-0 color-bg-default blob-code-inner js-file-line"> <span class="pl-smi">byte</span> <span class="pl-s1">callbackstatus</span> = <span class="pl-en">isCallBack</span>(<span class="pl-s1">url</span>, <span class="pl-s1">inv</span>.<span class="pl-en">getMethodName</span>(), <span class="pl-s1">paraIndex</span>); </td>
        </tr>
    </tbody></table>
  </div>
</div>
<br>
<code class="notranslate">callbackstatus </code><br>
Pls. provide [GitHub address] to reproduce this issue.<p></p>
<h3 dir="auto">Expected Result</h3>
<p dir="auto">What do you expected from the above steps？</p>
<h3 dir="auto">Actual Result</h3>
<p dir="auto">What actually happens?</p>
<p dir="auto">If there is an exception, please attach the exception trace:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Just put your stack trace here!"><pre class="notranslate"><code class="notranslate">Just put your stack trace here!
</code></pre></div>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have searched the <a href="https://github.com/apache/incubator-dubbo/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/apache/incubator-dubbo/blob/master/FAQ.md">FAQ</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h3 dir="auto">Environment</h3>
<ul dir="auto">
<li>Dubbo version: 2.6.5</li>
<li>Operating System version: Red Hat 4.8.5-11</li>
<li>Java version:1.8.0</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<ol dir="auto">
<li>consumer use http protocol</li>
<li>submit a POST request</li>
</ol>
<p dir="auto">Pls. provide [GitHub address] to reproduce this issue.</p>
<h3 dir="auto">Expected Result</h3>
<p dir="auto">response data</p>
<h3 dir="auto">Actual Result</h3>
<p dir="auto">report errors</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Invalid use of BasicClientConnManager: connection still allocated.
Make sure to release the connection before allocating another one.
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0]
	at "><pre class="notranslate"><code class="notranslate">java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Invalid use of BasicClientConnManager: connection still allocated.
Make sure to release the connection before allocating another one.
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0]
	at 
</code></pre></div>