Please format logs and config files using the </> button. Config files are sensitive to indentation (YAML file format). In your last example config the indentation of exclude_lines is off.
Tip: using ^.* or .*$ expresses a sub-string match. This is exactly what exclude_lines does. This config should work:
filebeat.prospectors:
- type: log
paths:
- /u04/jboss/standalone/log/server.log
- /var/log/soapradius.log
- /var/log/radius.log
exclude_lines: ['AbstractLoggingWriter']
output.logstash:
hosts: ["x.x.x.x:5044"]
index: "platform.wavespot.net"