The Java.net.UnknownHostException Solution

When using Java today, you encounter the following problems.

Org.apache.jasper.JasperException:Exception in JSP:/admin/_info.jsp:43

40:}
41:
42:string CollectionName = schema!=null? Schema.getname (): "Unknown";
43:inetaddress addr = Inetaddress.getlocalhost ();
44:string hostname = Addr.getcanonicalhostname ();
45:
46:string defaultsearch = "";


StackTrace:
Org.apache.jasper.servlet.JspServletWrapper.handleJspException (jspservletwrapper.java:467)
Org.apache.jasper.servlet.JspServletWrapper.service (jspservletwrapper.java:377)
Org.apache.jasper.servlet.JspServlet.serviceJspFile (jspservlet.java:315)
Org.apache.jasper.servlet.JspServlet.service (jspservlet.java:265)
Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
Org.apache.solr.servlet.SolrDispatchFilter.doFilter (solrdispatchfilter.java:133)

Root cause

Java.net.UnknownHostException:app10:app10
Java.net.InetAddress.getLocalHost (inetaddress.java:1308)
Org.apache.jsp.admin.index_jsp._jspservice (index_jsp.java:95)
Org.apache.jasper.runtime.HttpJspBase.service (httpjspbase.java:98)
Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
Org.apache.jasper.servlet.JspServletWrapper.service (jspservletwrapper.java:328)
Org.apache.jasper.servlet.JspServlet.serviceJspFile (jspservlet.java:315)
Org.apache.jasper.servlet.JspServlet.service (jspservlet.java:265)
Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
Org.apache.solr.servlet.SolrDispatchFilter.doFilter (solrdispatchfilter.java:133)

This is a problem caused by a java/dns, the possible causes are:

1 uses an unsuitable host name and cannot perform DNS resolution host.
2 when the JVM is running, the host name is changed and the host name returned in the cache does not match the server settings.

The solution, that is, two kinds of, first check your server name is set up in the hosts. If everything is correct, refresh the cache of the JVM.