问题日志：java.lang.IllegalArgumentException: Request header is too large
java.lang.IllegalArgumentException: Request header is too large
at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:701)
at org.apache.coyote.http11.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:455)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:667)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
解决方案
配置 tomcat server xml
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" maxHttpHeaderSize="65536" maxPostSize="4194304"
URIEncoding="UTF-8"/>
org.apache.coyote.http11.AbstractHttp11Protocol
原因分析：
在tomcat的org.apache.coyote.http11.AbstractHttp11Protocol类中定义了其默认值：
/**
* Maximum size of the HTTP message header.
*/
private int maxHttpHeaderSize = 8 * 1024;
所以，当请求头大于 8 * 1024，就会报错。针对这样的大数据量的请求，需要单独配置这个maxHttpHeaderSize的值。
