redis连接异常java.net.ConnectException: Connection refused (Connection refused)常见原因解析

当使用java程序连接redis服务器（单机或集群时）往往会出现如下异常：

Exception in thread "main" redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect
	at redis.clients.jedis.Connection.connect(Connection.java:207)
	at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:93)
	at redis.clients.jedis.Connection.sendCommand(Connection.java:126)
	at redis.clients.jedis.Connection.sendCommand(Connection.java:121)
	at redis.clients.jedis.BinaryClient.ping(BinaryClient.java:106)
	at redis.clients.jedis.BinaryJedis.ping(BinaryJedis.java:195)
	at com.atguigu.redis.test.TestPing.main(TestPing.java:10)
Caused by: java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
	at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
	at java.net.PlainSocketImpl.connect(Unknown Source)
	at java.net.SocksSocketImpl.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at redis.clients.jedis.Connection.connect(Connection.java:184)
	... 6 more

下面针对该异常分析一下相应的原因。

防火墙原因

针对防火墙的原因主要就是防火墙未开启访问权限，根据系统不同开启对应的端口和ip的防火墙访问权限即可。

这里需要注意的是，正常情况下如果我们使用6379端口，则需要同时开启16379端口。如果是集群情况，比如一台机器上使用了6379和6380，则需要同时开始16379和16380端口。

然后可通过telnet命令才测试是否端口开启成功：

telnet 192.168.1.118 6379

redis绑定原因

Redis默认情况下绑定是的localhost地址，因此，如果外网需要访问，则需要对绑定地址进行修改，具体配置在redis.conf文件中。

################################## NETWORK #####################################
 
# By default, if no "bind" configuration directive is specified, Redis listens
# for connections from all the network interfaces available on the server.
# It is possible to listen to just one or multiple selected interfaces using
# the "bind" configuration directive, followed by one or more IP addresses.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet, binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive, that will force Redis to listen only into
# the IPv4 lookback interface address (this means Redis will be able to
# accept connections only from clients running into the same computer it
# is running).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bind 127.0.0.1
bind 192.168.1.118
# Protected mode is a layer of security protection, in order to avoid that
# Redis instances left open on the internet are accessed and exploited.
#
# When protected mode is on and if:
#

修改对应的绑定地址即可，如果设置了密码，对绑定地址不限制，那可以绑定到0.0.0.0，表示绑定本机的所有地址。

DENIED Redis is running in protected mode （保护模式）

redis.clients.jedis.exceptions.JedisDataException: DENIED Redis is running in protected mode because protected mode is enabled, no bind address was specified, no authentication password is requested to clients. In this mode connections are only accepted from the loopback interface. If you want to connect from external computers to Redis you may adopt one of the following solutions: 1) Just disable protected mode sending the command 'CONFIG SET protected-mode no' from the loopback interface by connecting to Redis from the same host the server is running, however MAKE SURE Redis is not publicly accessible from internet if you do so. Use CONFIG REWRITE to make this change permanent. 2) Alternatively you can just disable the protected mode by editing the Redis configuration file, and setting the protected mode option to 'no', and then restarting the server. 3) If you started the server manually just for testing, restart it with the '--protected-mode no' option. 4) Setup a bind address or an authentication password. NOTE: You only need to do one of the above things in order for the server to start accepting connections from the outside.
    at redis.clients.jedis.Protocol.processError(Protocol.java:117)
    at redis.clients.jedis.Protocol.process(Protocol.java:142)
    at redis.clients.jedis.Protocol.read(Protocol.java:196)
    at redis.clients.jedis.Connection.readProtocolWithCheckingBroken(Connection.java:288)
    at redis.clients.jedis.Connection.getBinaryBulkReply(Connection.java:207)
    at redis.clients.jedis.Connection.getBulkReply(Connection.java:196)
    at redis.clients.jedis.Jedis.get(Jedis.java:98)
    at com.zyao89.jedis.JedisTest.test1(JedisTest.java:18)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

redis开启了protected mode，这也是Redis3.2加入的新特性，开启保护模式的redis只允许本机登录，同样设置在配置文件redis.conf中，如图：