@GetMapping("/project_metadata/spring-boot")
public String getMetadata(){
 return "{\"data\":1234}";//这个不重要
}

content = new JSONObject(restTemplate.getForObject(url, String.class));

2017-08-31 14:35:38.867 INFO 3450 --- [nio-8080-exec-1] .i.w.s.DefaultInitializrMetadataProvider : Fetching boot metadata from http://localhost:8080/project_metadata/spring-boot
2017-08-31 14:35:38.872 WARN 3450 --- [nio-8080-exec-1] .i.w.s.DefaultInitializrMetadataProvider : Failed to fetch spring boot metadata
org.springframework.web.client.HttpClientErrorException: 404 Not Found
 at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:63) ~[spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
 at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:700) ~[spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
 at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:653) ~[spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
 at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:613) ~[spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
 at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:287) ~[spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]

curl -I http://10.2.10.203:8080/project_metadata/spring-boot
HTTP/1.1 404 Not Found
server: ecstatic-1.4.1
Date: Thu, 31 Aug 2017 07:06:39 GMT
Connection: keep-alive

curl -I http://localhost:8080/project_metadata/spring-boot
HTTP/1.1 200
Content-Type: application/json;charset=UTF-8
Content-Length: 2683
Date: Thu, 31 Aug 2017 07:07:28 GMT

lsof -i:8080
COMMAND PID   USER  FD  TYPE       DEVICE SIZE/OFF NODE NAME
node  1045 pollyduan  13u IPv4 0x992085ef857b1d07   0t0 TCP *:http-alt (LISTEN)
java  3995 pollyduan  65u IPv6 0x992085ef905d994f   0t0 TCP *:http-alt (LISTEN)

Caused by: java.net.BindException: Address already in use
 at sun.nio.ch.Net.bind0(Native Method)
 at sun.nio.ch.Net.bind(Net.java:433)
 at sun.nio.ch.Net.bind(Net.java:425)
 at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
 at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
 at org.apache.tomcat.util.net.NioEndpoint.bind(NioEndpoint.java:340)
 at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:742)
 at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:458)
 at org.apache.coyote.http11.AbstractHttp11JsseProtocol.init(AbstractHttp11JsseProtocol.java:120)
 at org.apache.catalina.connector.Connector.initInternal(Connector.java:960)
 ... 13 more