java.net.UnknownHostException: "localhost": 名称或服务未知

Question

我正在尝试使用 Jedis 连接到 Java 中的 Redis。我这样做就像

return new JedisPool(jedisPoolConfig,
                    redisData.get("address").toString(),
                    redisData.get("port").asInt(),
                    2000,
                    redisData.get("password").toString());

和{"address": "localhost", "port": 6363, "password": "password}

但是，我在尝试连接时遇到此错误：

redis.clients.jedis.exceptions.JedisConnectionException: Failed to create socket.
    at redis.clients.jedis.DefaultJedisSocketFactory.createSocket(DefaultJedisSocketFactory.java:116)
    at redis.clients.jedis.Connection.connect(Connection.java:180)
    at redis.clients.jedis.Connection.initializeFromClientConfig(Connection.java:338)
    at redis.clients.jedis.Connection.<init>(Connection.java:53)
    at redis.clients.jedis.Jedis.<init>(Jedis.java:212)
    at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:181)
    at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:571)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:298)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:223)
    at redis.clients.jedis.util.Pool.getResource(Pool.java:34)
    at redis.clients.jedis.JedisPool.getResource(JedisPool.java:364)
    at org.myapp.monitors.Monitor$DefaultImpls.setRedis(Monitor.kt:13)
    at org.myapp.monitors.IntMonitor.setRedis(IntMonitor.kt:8)
    at org.myapp.monitors.IntMonitor.<init>(IntMonitor.kt:10)
    at org.myapp.monitors.IntMonitor.<init>(IntMonitor.kt:8)
    at org.myapp.monitors.MonitorFactory.makeMonitor(MonitorFactory.kt:22)
    at org.myapp.utils.ConfigUtils.getMonitors(ConfigUtils.java:62)
    at org.myapp.tp.TelPub.<clinit>(TelPub.kt:16)
Caused by: java.net.UnknownHostException: "localhost": Name or service not known
    at java.base/java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
    at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:932)
    at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1517)
    at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:851)
    at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1507)
    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1366)
    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1300)
    at redis.clients.jedis.DefaultJedisSocketFactory.connectToFirstSuccessfulHost(DefaultJedisSocketFactory.java:58)
    at redis.clients.jedis.DefaultJedisSocketFactory.createSocket(DefaultJedisSocketFactory.java:87)
    ... 17 more
Caused by: java.net.UnknownHostException: "localhost"
    at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:800)
    at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1507)
    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1366)
    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1300)
    at redis.clients.jedis.DefaultJedisSocketFactory.connectToFirstSuccessfulHost(DefaultJedisSocketFactory.java:58)
    at redis.clients.jedis.DefaultJedisSocketFactory.createSocket(DefaultJedisSocketFactory.java:87)
    ... 17 more

如果我将 "localhost" 替换为 "127.0.0.1" 或 "::1".

，也会发生同样的事情

我使用的是 popOS 21.10，这是我的 /etc/host 文件：

127.0.0.1   localhost
::1     localhost
127.0.1.1   pop-os.localdomain  pop-os

echo $HOST_NAME returns "thinkpad-t440p".

我试过了

127.0.0.1   thinkpad-t440p localhost
::1         localhost
127.0.1.1   pop-os.localdomain  pop-os

但同样的问题。

ping localhost 给我

PING localhost(localhost (::1)) 56 data bytes
64 bytes from localhost (::1): icmp_seq=1 ttl=64 time=0.025 ms

ping thinkpad-t440p 给我

PING thinkpad-t440p (192.168.0.42) 56(84) bytes of data.
64 bytes from thinkpad-t440p (192.168.0.42): icmp_seq=1 ttl=64 time=0.027 ms

Answer 1

确认你的 Redis 服务器在哪个端口运行。

With {"address": "localhost", "port": 6363, "password": "password}

Redis 默认运行在 6379 端口，而不是 6363。

Answer 2

问题出在使用 toString() 方法，该方法基本上是将一个字符串放在一个字符串中，以便为其添加额外的引号或其他内容。

需要改用asString()。

java.net.UnknownHostException: "localhost": 名称或服务未知

java.net.UnknownHostException: "localhost": Name or service not known

java

hosts

redis

jedis