In flume-env.sh file , i added the CLASSPATH
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk.x86_64
export JAVA_OPTS="-Xms100m -Xmx2000m -Dcom.sun.management.jmxremote"
FLUME_CLASSPATH="/usr/hdp/2.5.0.0-1245/flume/lib/*"
export HIVE_HOME=/usr/lib/hive
export HCAT_HOME=/usr/lib/hive-hcatalog
And here is the flume command which i used for execution,
flume-ng agent -n TwitterAgent --conf /etc/flume/conf -f /etc/flume/conf/tweets.conf -Dflume.root.logger=DEBUG,console -Dtwitter4j.streamBaseURL=https://stream.twitter.com/1.1/