Norman, thanks for your reply. I did mvn compile in the common sub project, and seems those error msgs are gone, so your solution works!
However, it pops up new errors when I was trying to run the examples. This time it seems to be redis related. I did went to sub projects such as handler and codec-redis and also the netty top folder and run mvn compile, the error msg still remains. I also tried to convert the project to a gradle project by running gradle init in the netty top folder, but it does not help. Any suggestion to fix this?
/Users/mxia/study/opensource/netty/example/src/main/java/io/netty/example/redis/RedisClient.java
Error:(27, 36) java: package io.netty.handler.codec.redis does not exist
Error:(28, 36) java: package io.netty.handler.codec.redis does not exist
Error:(29, 36) java: package io.netty.handler.codec.redis does not exist
Error:(30, 36) java: package io.netty.handler.codec.redis does not exist
Error:(53, 36) java: cannot find symbol
symbol: class RedisDecoder
Error:(54, 36) java: cannot find symbol
symbol: class RedisBulkStringAggregator
Error:(55, 36) java: cannot find symbol
symbol: class RedisArrayAggregator
Error:(56, 36) java: cannot find symbol
symbol: class RedisEncoder
/Users/mxia/study/opensource/netty/example/src/main/java/io/netty/example/redis/RedisClientHandler.java
Error:(24, 36) java: package io.netty.handler.codec.redis does not exist
Error:(25, 36) java: package io.netty.handler.codec.redis does not exist
Error:(26, 36) java: package io.netty.handler.codec.redis does not exist
Error:(27, 36) java: package io.netty.handler.codec.redis does not exist
Error:(28, 36) java: package io.netty.handler.codec.redis does not exist
Error:(29, 36) java: package io.netty.handler.codec.redis does not exist
Error:(66, 54) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(84, 37) java: cannot find symbol
symbol: class FullBulkStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(44, 14) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(44, 53) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(46, 30) java: cannot find symbol
symbol: class FullBulkStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(48, 9) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(48, 36) java: cannot find symbol
symbol: class ArrayRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(54, 9) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(54, 38) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(67, 28) java: cannot find symbol
symbol: class SimpleStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(68, 34) java: cannot find symbol
symbol: class SimpleStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(69, 35) java: cannot find symbol
symbol: class ErrorRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(70, 34) java: cannot find symbol
symbol: class ErrorRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(71, 35) java: cannot find symbol
symbol: class IntegerRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(72, 34) java: cannot find symbol
symbol: class IntegerRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(73, 35) java: cannot find symbol
symbol: class FullBulkStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(74, 43) java: cannot find symbol
symbol: class FullBulkStringRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(75, 35) java: cannot find symbol
symbol: class ArrayRedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(76, 18) java: cannot find symbol
symbol: class RedisMessage
location: class io.netty.example.redis.RedisClientHandler
Error:(76, 41) java: cannot find symbol
symbol: class ArrayRedisMessage
location: class io.netty.example.redis.RedisClientHandler