telnet: connect to address 127.0.0.1: Connection refused on MacOS - macos

Question

I'm trying to connect to my database from my java application, but it refuses the connection, the error given is this one.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:339)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2247)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2280)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at MainTest.main(MainTest.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:214)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:298)
... 20 more
Searching I found that the problem is not the code, but the connection to my localchost, since I can connect to localhost if I go to my web browser and just going to 'localhost', I can't make a telnet to localhost or 127.0.0.1, it refuses the connection.
MacBook-Pro:etc alejandro-trabajo$ telnet localhost
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
Trying fe80::1...
telnet: connect to address fe80::1: Connection refused
telnet: Unable to connect to remote host
I've tried everything I found in the web, make a new 'hosts' file, flushing the dns, restarting the apache server, uncommenting the "ServerName localhost" in the httpd.conf file... I really don't know what to do.
PS: The ping to localhost works perfectly
MacBook-Pro:etc alejandro-trabajo$ ping localhost
PING localhost (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.048 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.075 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.126 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.121 ms
^C
--- localhost ping statistics ---
4 packets transmitted, 4 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.048/0.092/0.126/0.032 ms

Answer 1

Maybe this will help.
~ $ ifconfig
...
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
ether 8c:85:90:94:fb:70
inet6 fe80::14aa:f1f1:ede3:b942%en0 prefixlen 64 secured scopeid 0x8
inet 192.168.1.100
~ $ telnet localhost 1234
Trying ::1...`enter code here`
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host
~ $ telnet 127.0.0.1 1234
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host
~ $ telnet 192.168.1.100 1234
Trying 192.168.1.100...
Connected to 192.168.1.100.
Escape character is '^]'.
This is a simple server