AsyncHttpClient exception异常源码流程解析
作者：codecraft
这篇文章主要为大家介绍了AsyncHttpClient的exception源码流程解析，有需要的朋友可以借鉴参考下，希望能够有所帮助，祝大家多多进步，早日升职加薪
序
本文主要研究一下AsyncHttpClient的exception
ChannelClosedException
org/asynchttpclient/exception/ChannelClosedException.java
public final class ChannelClosedException extends IOException {
public static final ChannelClosedException INSTANCE = unknownStackTrace(new ChannelClosedException(), ChannelClosedException.class, "INSTANCE");
private ChannelClosedException() {
super("Channel closed");
}
}ChannelClosedException用于表示Channel closed的异常
handleUnexpectedClosedChannel
org/asynchttpclient/netty/request/NettyRequestSender.java
public void handleUnexpectedClosedChannel(Channel channel, NettyResponseFuture<?> future) {
if (Channels.isActiveTokenSet(channel)) {
if (future.isDone()) {
channelManager.closeChannel(channel);
} else if (future.incrementRetryAndCheck() && retry(future)) {
future.pendingException = null;
} else {
abort(channel, future,
future.pendingException != null ? future.pendingException : RemotelyClosedException.INSTANCE);
}
}
}NettyRequestSender定义了handleUnexpectedClosedChannel方法，它会关闭或abort当前的channel
PoolAlreadyClosedException
org/asynchttpclient/exception/PoolAlreadyClosedException.java
public class PoolAlreadyClosedException extends IOException {
public static final PoolAlreadyClosedException INSTANCE = unknownStackTrace(new PoolAlreadyClosedException(), PoolAlreadyClosedException.class, "INSTANCE");
private PoolAlreadyClosedException() {
super("Pool is already closed");
}
}PoolAlreadyClosedException用于表示连接池已经关闭的异常
sendRequestWithNewChannel
org/asynchttpclient/netty/request/NettyRequestSender.java
private <T> ListenableFuture<T> sendRequestWithNewChannel(Request request,
ProxyServer proxy,
NettyResponseFuture<T> future,
AsyncHandler<T> asyncHandler) {
// some headers are only set when performing the first request
HttpHeaders headers = future.getNettyRequest().getHttpRequest().headers();
Realm realm = future.getRealm();
Realm proxyRealm = future.getProxyRealm();
requestFactory.addAuthorizationHeader(headers, perConnectionAuthorizationHeader(request, proxy, realm));
requestFactory.setProxyAuthorizationHeader(headers, perConnectionProxyAuthorizationHeader(request, proxyRealm));
future.setInAuth(realm != null && realm.isUsePreemptiveAuth() && realm.getScheme() != AuthScheme.NTLM);
future.setInProxyAuth(
proxyRealm != null && proxyRealm.isUsePreemptiveAuth() && proxyRealm.getScheme() != AuthScheme.NTLM);
try {
if (!channelManager.isOpen()) {
throw PoolAlreadyClosedException.INSTANCE;
}
// Do not throw an exception when we need an extra connection for a
// redirect.
future.acquirePartitionLockLazily();
} catch (Throwable t) {
abort(null, future, getCause(t));
// exit and don't try to resolve address
return future;
}
//......
}sendRequestWithNewChannel在channelManager非open的时候会抛出PoolAlreadyClosedException
RemotelyClosedException
org/asynchttpclient/exception/RemotelyClosedException.java
public final class RemotelyClosedException extends IOException {
public static final RemotelyClosedException INSTANCE = unknownStackTrace(new RemotelyClosedException(), RemotelyClosedException.class, "INSTANCE");
RemotelyClosedException() {
super("Remotely closed");
}
}RemotelyClosedException用于表示Remotely closed的异常
handleUnexpectedClosedChannel
org/asynchttpclient/netty/request/NettyRequestSender.java
public void handleUnexpectedClosedChannel(Channel channel, NettyResponseFuture<?> future) {
if (Channels.isActiveTokenSet(channel)) {
if (future.isDone()) {
channelManager.closeChannel(channel);
} else if (future.incrementRetryAndCheck() && retry(future)) {
future.pendingException = null;
} else {
abort(channel, future,
future.pendingException != null ? future.pendingException : RemotelyClosedException.INSTANCE);
}
}
}NettyRequestSender的handleUnexpectedClosedChannel的时候，对于future未完成也没有重试的时候会执行abort，并抛出RemotelyClosedException
TooManyConnectionsException
org/asynchttpclient/exception/TooManyConnectionsException.java
public class TooManyConnectionsException extends IOException {
public TooManyConnectionsException(int max) {
super("Too many connections: " + max);
}
}TooManyConnectionsException用于表示全局连接超过限制的异常
TooManyConnectionsPerHostException
org/asynchttpclient/exception/TooManyConnectionsPerHostException.java
public class TooManyConnectionsPerHostException extends IOException {
public TooManyConnectionsPerHostException(int max) {
super("Too many connections: " + max);
}
}TooManyConnectionsPerHostException用于表示连接超出单host限制的异常
acquireChannelLock
org/asynchttpclient/netty/channel/ConnectionSemaphore.java
public void acquireChannelLock(Object partitionKey) throws IOException {
if (!tryAcquireGlobal())
throw tooManyConnections;
if (!tryAcquirePerHost(partitionKey)) {
freeChannels.release();
throw tooManyConnectionsPerHost;
}
}acquireChannelLock方法在全局连接超出限制时抛出tooManyConnections，在单host连接超出限制时抛出tooManyConnectionsPerHost
小结
AsyncHttpClient一共定义了五个异常，它们都继承了IOException，分别是ChannelClosedException、PoolAlreadyClosedException、RemotelyClosedException、TooManyConnectionsException、TooManyConnectionsPerHostException。
以上就是AsyncHttpClient的exception的详细内容，更多关于AsyncHttpClient的exception的资料请关注脚本之家其它相关文章！