hello wordが表示されない HTTP Status 400

前提・実現したいこと

http://localhost:8080/ にアクセスして
spring bootでhello word と表示させたい

発生している問題・エラーメッセージ

2021-04-17 17:02:34.597[0;39m [32m INFO[0;39m [35m13325[0;39m [2m---[0;39m [2m[nio-8080-exec-1][0;39m [36mo.apache.coyote.http11.Http11Processor  [0;39m [2m:[0;39m Error parsing HTTP request header
 Note: further occurrences of HTTP request parsing errors will be logged at DEBUG level.

java.lang.IllegalArgumentException: Request header is too large
	at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:779) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.coyote.http11.Http11InputBuffer.parseHeader(Http11InputBuffer.java:946) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.coyote.http11.Http11InputBuffer.parseHeaders(Http11InputBuffer.java:593) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:284) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1707) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.45.jar:9.0.45]
	at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

Type Exception Report

Message Request header is too large

Description The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).

Exception

java.lang.IllegalArgumentException: Request header is too large
	org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:779)
	org.apache.coyote.http11.Http11InputBuffer.parseHeader(Http11InputBuffer.java:946)
	org.apache.coyote.http11.Http11InputBuffer.parseHeaders(Http11InputBuffer.java:593)
	org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:284)
	org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
	org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1707)
	org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	java.base/java.lang.Thread.run(Thread.java:834)
Note The full stack trace of the root cause is available in the server logs.

該当のソースコード

package com.example.demo;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class HelloWorld {
	
	 @GetMapping("/") // ②
	    public String hello() {
	        return "hello"; // ③
	    }
}

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>baseball</title>
  </head>
  <body>
    <h1>HelloWorld</h1>
  </body>
</html>

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MyappApplication {

	public static void main(String[] args) {
		SpringApplication.run(MyappApplication.class, args);
	}

}