前提:redis服务器已经运行,且端口号,服务器地址都已经配置正常,但任然抛出无法获取连接异常
原来的代码如下:
@Bean
public JedisConnectionFactory connectionFactory(){
JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
(true);
(jedisPoolConfig());
((""));
((("")));
return jedisConnectionFactory;
}
其他配置都很正常,但是运行后会抛出空指针异常。
Request processing failed; nested exception is : Cannot get Jedis connection; nested exception is
解决方法如下,在return前添加如下代码
();
看源码便知原因:看jedis如何获取到连接的:
public JedisConnection getConnection() {
Jedis jedis = fetchJedisConnector();
JedisConnection connection = (usePool ? new JedisConnection(jedis, pool, dbIndex) : new JedisConnection(jedis,
null, dbIndex));
(convertPipelineAndTxResults);
return postProcessConnection(connection);
}
我们看fetchJedisConnector()方法:
protected Jedis fetchJedisConnector() {
try {
if (usePool && pool != null) {
return ();
}
Jedis jedis = new Jedis(getShardInfo());
// force initialization (see Jedis issue #82)
();
return jedis;
} catch (Exception ex) {
throw new RedisConnectionFailureException("Cannot get Jedis connection", ex);
}
}
如果没用用pool的话,需要用到getShardInfo()方法,而这个方法就是返回一个JedisShardInfo shardInfo。那么这个JedisShardInfo shardInfo在什么时候初始化呢?查看后发现,哈哈在这:
public void afterPropertiesSet() {
if (shardInfo == null) {
shardInfo = new JedisShardInfo(hostName, port);
if ((password)) {
(password);
}
if (timeout > 0) {
setTimeoutOn(shardInfo, timeout);
}
}
if (usePool) {
= createPool();
}
}
这个方法将在所有的属性被初始化后调用。但是会在init前调用。是spring中InitializingBean接口的方法。spring-data-redis里面实现了它。在这里对shardIndo类进行了初始化。所以,我们只要在代码中添加:
();
这句就可以啦。再运行一次,连接成功!