golang tls 似乎例子

Hi,

Can you help to figure out what's wrong with the following TLS test code?
It's just a echo server,the expected result is to get echo string from
server,but client always gets nothing.

client.go:
===============================================================
package main

import ( "fmt" ; "crypto/tls"; "os" )

func main() {
conn,err := tls.Dial("tcp","127.0.0.1:8000",nil)
if err != nil {
fmt.Println("Fatal error ",err.String())
os.Exit(1)
}
defer conn.Close()
state := conn.ConnectionState()

fmt.Println("handshaked: ",state.HandshakeComplete)
fmt.Println("NegotiatedProtocolIsMutual: ",
state.NegotiatedProtocolIsMutual)
fmt.Println("local address: ",conn.LocalAddr())
conn.Write([]byte("Hello"))
var retbuf []byte
// conn.SetReadTimeout(1000000)
n,error := conn.Read(retbuf)
fmt.Println(n," bytes read from socket",error)
fmt.Println(string(retbuf))

server.go
===============================================================
package main

import ("fmt"; "os"; "crypto/tls"; "net"; "crypto/rand"; "time")

func main() {

cert,err :=
tls.LoadX509KeyPair("/etc/ssl/certs/ssl-cert-snakeoil.pem",
"/etc/ssl/private/ssl-cert-snakeoil.key")
//cert,err := tls.LoadX509KeyPair("jan.newmarch.name.pem",
"private.pem")
checkError(err)
config := tls.Config {Certificates: []tls.Certificate {cert}}

now := time.Seconds()
config.Time = func() int64 { return now }
config.Rand = rand.Reader

service := "0.0.0.0:8000"

listener,err := tls.Listen("tcp",service,&config)
checkError(err)
fmt.Println("Listening")
for {
conn,err := listener.Accept()
if err != nil {
fmt.Println(err.String())
continue
}
fmt.Println("Accepted")
//tlsConn := tls.Server(conn,&config)
go handleClient(conn)
}