RedisTemplat 使用scan获取所有key,单点模式和集群模式。
单点:public Set<String> scan(String matchKey) {Set<String> keys = (Set<String>) redisTemplate.execute((RedisCallback<Set<String>>) connection -> {Set<String> keysT
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单点:
public Set<String> scan(String matchKey) {
Set<String> keys = (Set<String>) redisTemplate.execute((RedisCallback<Set<String>>) connection -> {
Set<String> keysTmp = new HashSet<>();
Cursor<byte[]> cursor = connection.scan(new ScanOptions.ScanOptionsBuilder().match(matchKey).count(1000).build());
while (cursor.hasNext()) {
keysTmp.add(new String(cursor.next()));
}
return keysTmp;
});
return keys;
}
测试:
@Test
public void scan() {
Set<String> stringSet = redisService.scan("*es*");
System.out.println("*******************************************");
System.out.println(stringSet);
System.out.println("*******************************************");
}
原文很详细:Spring RedisTemplate实现scan操作,毕竟keys不安全
集群:
public List<String> getRedisKeys(String matchKey) {
List<String> list = new ArrayList<>();
RedisClusterConnection redisClusterConnection = redisTemplate.getConnectionFactory().getClusterConnection();
//这里是获取edispool的另外一种方式与上边的pipline可以对比下,两种方式都可以实现
Map<String, JedisPool> clusterNodes = ((JedisCluster) redisClusterConnection.getNativeConnection()).getClusterNodes();
for (Map.Entry<String, JedisPool> entry : clusterNodes.entrySet()) {
//获取单个的jedis对象
Jedis jedis = entry.getValue().getResource();
// 判断非从节点(因为若主从复制,从节点会跟随主节点的变化而变化),此处要使用主节点从主节点获取数据
if (!jedis.info("replication").contains("role:slave")) {
List<String> keys = getScan(jedis, matchKey);
if (keys.size() > 0) {
Map<Integer, List<String>> map = new HashMap<>(8);
//接下来的循环不是多余的,需要注意
for (String key : keys) {
// cluster模式执行多key操作的时候,这些key必须在同一个slot上,不然会报:JedisDataException:
int slot = JedisClusterCRC16.getSlot(key);
// 按slot将key分组,相同slot的key一起提交
if (map.containsKey(slot)) {
map.get(slot).add(key);
} else {
List<String> list1 = new ArrayList();
list1.add(key);
map.put(slot, list1);
}
}
for (Map.Entry<Integer, List<String>> integerListEntry : map.entrySet()) {
list.addAll(integerListEntry.getValue());
}
}
}
}
return list;
}
public List<String> getScan(Jedis redisService, String key) {
List<String> list = new ArrayList<>();
//扫描的参数对象创建与封装
ScanParams params = new ScanParams();
params.match(key);
//扫描返回一百行,这里可以根据业务需求进行修改
params.count(100);
String cursor = "0";
ScanResult scanResult = redisService.scan(cursor, params);
//scan.getStringCursor() 存在 且不是 0 的时候,一直移动游标获取
while (null != scanResult.getStringCursor()) {
//封装扫描的结果
list.addAll(scanResult.getResult());
if (! "0".equals( scanResult.getStringCursor())) {
scanResult = redisService.scan(cursor, params);
} else {
break;
}
}
return list;
}
测试:
@Test
public void getRedisKeys() {
List<String> list = redisService.getRedisKeys("*es*");
System.out.println("*******************************************");
System.out.println(list);
System.out.println("*******************************************");
}
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