No... this doesn't work. Firebase gives me 400 Bad Request in this case.
Although i did implement a retry mechanism wherein the failure rate has reduced a lot but still certain request to FCM failed upon retrying with error -
SEVERE: Unhandled exception
java.lang.IllegalStateException: Response is closed
at io.vertx.core.http.impl.HttpServerResponseImpl.checkValid(HttpServerResponseImpl.java:576)
at io.vertx.core.http.impl.HttpServerResponseImpl.end(HttpServerResponseImpl.java:324)
at io.vertx.core.http.impl.HttpServerResponseImpl.end(HttpServerResponseImpl.java:367)
at com.avaya.apnsproxy.http.HttpProxy.handleApnsRequestException(HttpProxy.java:337)
at com.avaya.apnsproxy.http.HttpProxy.lambda$retryRequest$1(HttpProxy.java:77)
at io.vertx.core.http.impl.HttpClientRequestBase.handleException(HttpClientRequestBase.java:139)
at io.vertx.core.http.impl.HttpClientRequestBase.doHandleResponse(HttpClientRequestBase.java:177)
at io.vertx.core.http.impl.HttpClientRequestBase.checkHandleResponse(HttpClientRequestBase.java:162)
at io.vertx.core.http.impl.HttpClientRequestBase.handleResponse(HttpClientRequestBase.java:146)
at io.vertx.core.http.impl.Http1xClientConnection.handleResponseBegin(Http1xClientConnection.java:624)
at io.vertx.core.http.impl.Http1xClientConnection.handleHttpMessage(Http1xClientConnection.java:594)
at io.vertx.core.http.impl.Http1xClientConnection.handleMessage(Http1xClientConnection.java:560)
at io.vertx.core.net.impl.ConnectionBase.handleRead(ConnectionBase.java:397)
at io.vertx.core.impl.ContextImpl.executeTask(ContextImpl.java:320)
at io.vertx.core.impl.EventLoopContext.execute(EventLoopContext.java:43)
at io.vertx.core.impl.ContextImpl.executeFromIO(ContextImpl.java:188)
at io.vertx.core.net.impl.VertxHandler.channelRead(VertxHandler.java:174)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:426)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:278)
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1429)
at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1199)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1243)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:502)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:441)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:278)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:644)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:579)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:496)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:458)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:897)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:834)
Can anybody point me why is this happening ?