Java Redis/Jedis - 按模式删除？
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Redis/Jedis - Delete by pattern?
提问by iCodeLikeImDrunk
Normally, I get the key set then use a look to delete each key/value pair.
通常，我获取键集然后使用外观删除每个键/值对。
Is it possible to just delete all keys via pattern?
是否可以通过模式删除所有键？
ie:
IE：
Del sample_pattern:*
采纳答案by iCodeLikeImDrunk
It seems, for Jedis, to "delete by pattern" is basically getting all the keys of a specific pattern then loop through it.
对于 Jedis 来说，“按模式删除”似乎基本上是获取特定模式的所有键，然后循环遍历它。
ie
IE
Set<String> keys = jedis.keys(pattern);
for (String key : keys) {
jedis.del(key);
}
回答by Agis
You can do it with bash:
你可以用 bash 做到这一点：
$ redis-cli KEYS "sample_pattern:*" | xargs redis-cli DEL
回答by corindiano
You should try using eval. I'm no Lua expert, but this code works.
您应该尝试使用eval。我不是 Lua 专家，但此代码有效。
private static final String DELETE_SCRIPT_IN_LUA =
"local keys = redis.call('keys', '%s')" +
" for i,k in ipairs(keys) do" +
" local res = redis.call('del', k)" +
" end";
public void deleteKeys(String pattern) {
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
if (jedis == null) {
throw new Exception("Unable to get jedis resource!");
}
jedis.eval(String.format(DELETE_SCRIPT_IN_LUA, pattern));
} catch (Exception exc) {
if (exc instance of JedisConnectionException && jedis != null) {
jedisPool.returnBrokenResource(jedis);
jedis = null;
}
throw new RuntimeException("Unable to delete that pattern!");
} finally {
if (jedis != null) {
jedisPool.returnResource(jedis);
}
}
}
And then call:
然后调用：
deleteKeys("temp:keys:*");
This guarantees a one server-side call, multiple delete operation.
这保证了一次服务器端调用，多次删除操作。
回答by Nikita Koksharov
回答by VanThaoNguyen
Using java to delete, it's seem like this:
用java删除，好像是这样的：
String keyPattern = "sample_pattern:*";
Set<String> keys = jedis.keys(keyPattern);
for(String key:keys){
jedis.del(key);
}
回答by Aprille
KEYS is not recommended to use due to its inefficiencies when used in production. Please see https://redis.io/commands/keys. Instead, it is better to use SCAN. Additionally, a more efficient call than repeated calls to jedis.del() is to make one single call to jedis to remove the matching keys, passing in an array of keys to delete. A more efficient solution is presented below:
不建议使用 KEYS，因为它在生产中使用效率低下。请参阅https://redis.io/commands/keys。相反，最好使用 SCAN。此外，比重复调用 jedis.del() 更有效的调用是对 jedis 进行一次调用以删除匹配的键，传入要删除的键数组。下面给出了一个更有效的解决方案：
Set<String> matchingKeys = new HashSet<>();
ScanParams params = new ScanParams();
params.match("sample_pattern:*");
try(Jedis jedis = jedisPoolFactory.getPool().getResource()) {
String nextCursor = "0";
do {
ScanResult<String> scanResult = jedis.scan(nextCursor, params);
List<String> keys = scanResult.getResult();
nextCursor = scanResult.getStringCursor();
matchingKeys.addAll(keys);
} while(!nextCursor.equals("0"));
if (matchingKeys.size() == 0) {
return;
}
jedis.del(matchingKeys.toArray(new String[matchingKeys.size()]));
}
