org.springframework.data.redis.core.Cursor Java Examples

/**
 * 查找匹配key
 * @param pattern key
 * @return /
 */
public List<String> scan(String pattern) {
    ScanOptions options = ScanOptions.scanOptions().match(pattern).build();
    RedisConnectionFactory factory = redisTemplate.getConnectionFactory();
    RedisConnection rc = Objects.requireNonNull(factory).getConnection();
    Cursor<byte[]> cursor = rc.scan(options);
    List<String> result = new ArrayList<>();
    while (cursor.hasNext()) {
        result.add(new String(cursor.next()));
    }
    try {
        RedisConnectionUtils.releaseConnection(rc, factory);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return result;
}
 

@Scheduled(cron = "0 10 2 * * ?")
@Transactional(rollbackFor = Exception.class)
public void clear() {
    System.out.println("开始清理收藏");
    //获取keylist
    final ScanOptions scanOptions = ScanOptions.scanOptions().match(RedisKeyConstant.ILLUST_BROWSING_HISTORY_REDIS_PRE + "*").build();
    RedisConnection connection = stringRedisTemplate.getConnectionFactory().getConnection();
    Cursor<byte[]> cursor = connection.scan(scanOptions);
    int i = 0;
    while (cursor.hasNext()) {
        connection.zRemRangeByScore(cursor.next(), LocalDateTime.now().plusDays(-3).toEpochSecond(ZoneOffset.of("+8")), -Integer.MAX_VALUE);
        i++;
    }
    illustHistoryMapper.deleteIllustHistory();
    illustHistoryMapper.tempToIllustHistory();
    illustHistoryMapper.truncateTemp();
}
 

@Override
public Cursor<V> scan(K key, final ScanOptions options) {

	final byte[] rawKey = rawKey(key);
	return execute(new RedisCallback<Cursor<V>>() {

		@Override
		public Cursor<V> doInRedis(RedisConnection connection) throws DataAccessException {
			return new ConvertingCursor<byte[], V>(connection.sScan(rawKey, options), new Converter<byte[], V>() {

				@Override
				public V convert(byte[] source) {
					return deserializeValue(source);
				}
			});
		}
	}, true);

}
 

@Override
public Cursor<TypedTuple<V>> scan(K key, final ScanOptions options) {

	final byte[] rawKey = rawKey(key);
	Cursor<Tuple> cursor = execute(new RedisCallback<Cursor<Tuple>>() {

		@Override
		public Cursor<Tuple> doInRedis(RedisConnection connection) throws DataAccessException {
			connection.select(dbIndex);
			return connection.zScan(rawKey, options);
		}
	}, true);

	return new ConvertingCursor<Tuple, TypedTuple<V>>(cursor, new Converter<Tuple, TypedTuple<V>>() {

		@Override
		public TypedTuple<V> convert(Tuple source) {
			return deserializeTuple(source);
		}
	});
}
 

/**
 * 根据匹配删除redis key,如想删除 notify_ 开头的所有key match就为notify_*
 * 
 * @author xuyisu
 * @date 2018年7月18日
 * 
 * @param match
 */
public void deleteByMatch(String match){
	redisConnection = redisConnectionFactory.getConnection();
    Cursor<byte[]> cursor = redisConnection.scan(new ScanOptions.ScanOptionsBuilder().match(match).build());
    Set<String> set = new HashSet<String>();
    while (cursor.hasNext()){
        set.add((new String(cursor.next())));
        if (set.size() >= 3000){
            redisTemplate.delete(set);
            set.clear();
        }
    }
    if (set.size() > 0){
        System.out.println(set.size());
        redisTemplate.delete(set);
    }
    redisConnection.close();
}
 

/**
* @Description: 从Redis获取博文点赞数
* @Param: []
* @return: java.util.List<com.zzx.model.pojo.Blog>
* @Author: Tyson
* @Date: 2020/5/30/0030 11:35
*/
public List<Blog> getBlogLikeCountFromRedis() {
    List<Blog> blogList = new ArrayList<>();
    try {
        Cursor<Map.Entry<Object, Object>> cursor = redisTemplate.opsForHash().scan(RedisConfig.MAP_BLOG_LIKE_COUNT_KEY, ScanOptions.NONE);
        while (cursor.hasNext()) {
            Map.Entry<Object, Object> entry = cursor.next();

            String key = (String)entry.getKey();
            int blogId = Integer.parseInt(key);
            int count = Integer.parseInt((String)entry.getValue());

            Blog blog = new Blog(blogId, count);

            blogList.add(blog);
            //从redis删除key
            redisTemplate.opsForHash().delete(RedisConfig.MAP_BLOG_LIKE_COUNT_KEY, key);
        }
        cursor.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return blogList;
}
 

@Override
public long removeByPattern(final String regex) throws IOException {
    return withConnection(redisConnection -> {
        long deletedCount = 0;
        final List<byte[]> batchKeys = new ArrayList<>();

        // delete keys in batches of 1000 using the cursor
        final Cursor<byte[]> cursor = redisConnection.scan(ScanOptions.scanOptions().count(100).match(regex).build());
        while (cursor.hasNext()) {
            batchKeys.add(cursor.next());

            if (batchKeys.size() == 1000) {
                deletedCount += redisConnection.del(getKeys(batchKeys));
                batchKeys.clear();
            }
        }

        // delete any left-over keys if some were added to the batch but never reached 1000
        if (batchKeys.size() > 0) {
            deletedCount += redisConnection.del(getKeys(batchKeys));
            batchKeys.clear();
        }

        return deletedCount;
    });
}
 

/**
 * 分页获取指定格式key，使用 scan 命令代替 keys 命令，在大数据量的情况下可以提高查询效率
 *
 * @param patternKey  key格式
 * @param currentPage 当前页码
 * @param pageSize    每页条数
 * @return 分页获取指定格式key
 */
public PageResult<String> findKeysForPage(String patternKey, int currentPage, int pageSize) {
    ScanOptions options = ScanOptions.scanOptions()
            .match(patternKey)
            .build();
    RedisConnectionFactory factory = stringRedisTemplate.getConnectionFactory();
    RedisConnection rc = factory.getConnection();
    Cursor<byte[]> cursor = rc.scan(options);

    List<String> result = Lists.newArrayList();

    long tmpIndex = 0;
    int startIndex = (currentPage - 1) * pageSize;
    int end = currentPage * pageSize;
    while (cursor.hasNext()) {
        String key = new String(cursor.next());
        if (tmpIndex >= startIndex && tmpIndex < end) {
            result.add(key);
        }
        tmpIndex++;
    }

    try {
        cursor.close();
        RedisConnectionUtils.releaseConnection(rc, factory);
    } catch (Exception e) {
        log.warn("Redis连接关闭异常，", e);
    }

    return new PageResult<>(result, tmpIndex);
}
 

public List<String> findKeysForPage(String patternKey, int pageNum, int pageSize) {

		Set<String> execute = redisTemplate.execute(new RedisCallback<Set<String>>() {

			@Override
			public Set<String> doInRedis(RedisConnection connection) throws DataAccessException {

				Set<String> binaryKeys = new HashSet<>();

				Cursor<byte[]> cursor = connection
						.scan(new ScanOptions.ScanOptionsBuilder().match(patternKey).count(1000).build());
				int tmpIndex = 0;
				int startIndex = (pageNum - 1) * pageSize;
				int end = pageNum * pageSize;
				while (cursor.hasNext()) {
					if (tmpIndex >= startIndex && tmpIndex < end) {
						binaryKeys.add(new String(cursor.next()));
						tmpIndex++;
						continue;
					}

					// 获取到满足条件的数据后,就可以退出了
					if (tmpIndex >= end) {
						break;
					}

					tmpIndex++;
					cursor.next();
				}
				connection.close();
				return binaryKeys;
			}
		});

		List<String> result = new ArrayList<String>(pageSize);
		result.addAll(execute);
		return result;
	}
 

@Test
public void testZScan() {
    connection.zAdd("key".getBytes(), 1, "value1".getBytes());
    connection.zAdd("key".getBytes(), 2, "value2".getBytes());

    Cursor<RedisZSetCommands.Tuple> t = connection.zScan("key".getBytes(), ScanOptions.scanOptions().build());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value1".getBytes());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value2".getBytes());
}
 

/**
 * 分页获取指定格式key，使用 scan 命令代替 keys 命令，在大数据量的情况下可以提高查询效率
 *
 * @param patternKey  key格式
 * @param currentPage 当前页码
 * @param pageSize    每页条数
 * @return 分页获取指定格式key
 */
public PageResult<String> findKeysForPage(String patternKey, int currentPage, int pageSize) {
    ScanOptions options = ScanOptions.scanOptions()
            .match(patternKey)
            .build();
    RedisConnectionFactory factory = stringRedisTemplate.getConnectionFactory();
    RedisConnection rc = factory.getConnection();
    Cursor<byte[]> cursor = rc.scan(options);

    List<String> result = Lists.newArrayList();

    long tmpIndex = 0;
    int startIndex = (currentPage - 1) * pageSize;
    int end = currentPage * pageSize;
    while (cursor.hasNext()) {
        String key = new String(cursor.next());
        if (tmpIndex >= startIndex && tmpIndex < end) {
            result.add(key);
        }
        tmpIndex++;
    }

    try {
        cursor.close();
        RedisConnectionUtils.releaseConnection(rc, factory);
    } catch (Exception e) {
        log.warn("Redis连接关闭异常，", e);
    }

    return new PageResult<>(result, tmpIndex);
}
 

@Override
public Cursor<Entry<HK, HV>> scan(K key, final ScanOptions options) {

	final byte[] rawKey = rawKey(key);
	return execute(new RedisCallback<Cursor<Map.Entry<HK, HV>>>() {

		@Override
		public Cursor<Entry<HK, HV>> doInRedis(RedisConnection connection) throws DataAccessException {

			return new ConvertingCursor<Map.Entry<byte[], byte[]>, Map.Entry<HK, HV>>(connection.hScan(rawKey, options),
					new Converter<Map.Entry<byte[], byte[]>, Map.Entry<HK, HV>>() {

						@Override
						public Entry<HK, HV> convert(final Entry<byte[], byte[]> source) {

							return new Map.Entry<HK, HV>() {

								@Override
								public HK getKey() {
									return deserializeHashKey(source.getKey());
								}

								@Override
								public HV getValue() {
									return deserializeHashValue(source.getValue());
								}

								@Override
								public HV setValue(HV value) {
									throw new UnsupportedOperationException("Values cannot be set when scanning through entries.");
								}
							};

						}
					});
		}

	}, true);

}
 

/**
* @Description: 从Redis获取用户点赞数据
* @Param: []
* @return: java.util.List<com.zzx.model.pojo.UserLike>
* @Author: Tyson
* @Date: 2020/5/30/0030 11:37
*/
public List<UserLike> getUserLikeFromRedis() {
    List<UserLike> userLikeList = new ArrayList<>();
    try {
        Cursor<Map.Entry<Object, Object>> cursor = redisTemplate.opsForHash().scan(RedisConfig.MAP_USER_LIKE_KEY, ScanOptions.NONE);
        while (cursor.hasNext()) {
            Map.Entry<Object, Object> entry = cursor.next();

            String key = (String)entry.getKey();
            //拆分key，blogId::userId
            String[] keyArr = key.split(RedisConfig.REDIS_LIKE_MID);
            int blogId  = Integer.parseInt(keyArr[0]);
            int userId= Integer.parseInt(keyArr[1]);
            int status = Integer.parseInt((String)entry.getValue());

            UserLike userLike = new UserLike(blogId, userId, status);

            userLikeList.add(userLike);
            //从redis删除key
            redisTemplate.opsForHash().delete(RedisConfig.MAP_USER_LIKE_KEY, key);
        }
        cursor.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return userLikeList;
}
 

@Test
public void testZScan() {
    connection.zAdd("key".getBytes(), 1, "value1".getBytes());
    connection.zAdd("key".getBytes(), 2, "value2".getBytes());

    Cursor<RedisZSetCommands.Tuple> t = connection.zScan("key".getBytes(), ScanOptions.scanOptions().build());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value1".getBytes());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value2".getBytes());
}
 

/**
 * 分页查询 key
 * @param patternKey key
 * @param page 页码
 * @param size 每页数目
 * @return /
 */
public List<String> findKeysForPage(String patternKey, int page, int size) {
    ScanOptions options = ScanOptions.scanOptions().match(patternKey).build();
    RedisConnectionFactory factory = redisTemplate.getConnectionFactory();
    RedisConnection rc = Objects.requireNonNull(factory).getConnection();
    Cursor<byte[]> cursor = rc.scan(options);
    List<String> result = new ArrayList<>(size);
    int tmpIndex = 0;
    int fromIndex = page * size;
    int toIndex = page * size + size;
    while (cursor.hasNext()) {
        if (tmpIndex >= fromIndex && tmpIndex < toIndex) {
            result.add(new String(cursor.next()));
            tmpIndex++;
            continue;
        }
        // 获取到满足条件的数据后,就可以退出了
        if(tmpIndex >=toIndex) {
            break;
        }
        tmpIndex++;
        cursor.next();
    }
    try {
        RedisConnectionUtils.releaseConnection(rc, factory);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return result;
}
 

/**
 * Uses {@code SCAN} command for loading all matching keys. <br />
 * {@code SCAN} uses a cursor on server side returning only a subset of the available data with the possibility to
 * ripple load further elements using the cursors position. <br />
 * All keys will be loaded using <strong>multiple</strong> operations.
 */
@Test
public void iterateOverKeysMatchingPrefixUsingScanCommand() {

	generateRandomKeys(1000);

	Cursor<byte[]> cursor = this.connection.scan(ScanOptions.scanOptions().match(KEY_PATTERN).build());
	printKeys(cursor);
}
 

@Test
public void testZScan() {
    connection.zAdd("key".getBytes(), 1, "value1".getBytes());
    connection.zAdd("key".getBytes(), 2, "value2".getBytes());

    Cursor<RedisZSetCommands.Tuple> t = connection.zScan("key".getBytes(), ScanOptions.scanOptions().build());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value1".getBytes());
    assertThat(t.hasNext()).isTrue();
    assertThat(t.next().getValue()).isEqualTo("value2".getBytes());
}
 

/**
 * 分页获取指定格式key，使用 scan 命令代替 keys 命令，在大数据量的情况下可以提高查询效率
 *
 * @param patternKey  key格式
 * @param currentPage 当前页码
 * @param pageSize    每页条数
 * @return 分页获取指定格式key
 */
public PageResult<String> findKeysForPage(String patternKey, int currentPage, int pageSize) {
    ScanOptions options = ScanOptions.scanOptions()
            .match(patternKey)
            .build();
    RedisConnectionFactory factory = stringRedisTemplate.getConnectionFactory();
    RedisConnection rc = factory.getConnection();
    Cursor<byte[]> cursor = rc.scan(options);

    List<String> result = Lists.newArrayList();

    long tmpIndex = 0;
    int startIndex = (currentPage - 1) * pageSize;
    int end = currentPage * pageSize;
    while (cursor.hasNext()) {
        String key = new String(cursor.next());
        if (tmpIndex >= startIndex && tmpIndex < end) {
            result.add(key);
        }
        tmpIndex++;
    }

    try {
        cursor.close();
        RedisConnectionUtils.releaseConnection(rc, factory);
    } catch (Exception e) {
        log.warn("Redis连接关闭异常，", e);
    }

    return new PageResult<>(result, tmpIndex);
}
 

@Test
public void testScanCommand() {
    RedisConnection connection = Objects.requireNonNull(stringRedisTemplate.getConnectionFactory()).getConnection();
    Cursor<byte[]> cursor = connection.scan(ScanOptions.scanOptions().match("*").count(Integer.MAX_VALUE).build());
    while (cursor.hasNext()) {
        byte[] next = cursor.next();
        log.info(new String(next));
    }
}
 

@Override
public Cursor<byte[]> sScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.SSCAN, key, () -> connection.sScan(key, options));
}
 

@Override
public Cursor<byte[]> scan(ScanOptions options) {
    return redisConnection.scan(options);
}
 

@Override
public Cursor<Tuple> zScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.ZSCAN, key, () -> connection.zScan(key, options));
}
 

@Override
public Cursor<Entry<byte[], byte[]>> hScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.HSCAN, key, () -> connection.hScan(key, options));
}
 

@Override
public Cursor<byte[]> scan(RedisClusterNode node, ScanOptions options) {
  return helper.doInScope(SCAN, () -> connection.scan(node, options));
}
 

@Override
public Cursor<byte[]> scan(ScanOptions options) {
  return helper.doInScope(RedisCommand.SCAN, () -> connection.scan(options));
}
 

@Override
public Cursor<byte[]> sScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.SSCAN, key, () -> connection.sScan(key, options));
}
 

@Override
public Cursor<Tuple> zScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.ZSCAN, key, () -> connection.zScan(key, options));
}
 

@Override
public Cursor<Entry<byte[], byte[]>> hScan(byte[] key, ScanOptions options) {
  return helper.doInScope(RedisCommand.HSCAN, key, () -> connection.hScan(key, options));
}
 

@Override
public Cursor<V> scan(ScanOptions options) {
	return ops.scan(getKey(), options);
}
 

@Override
public Cursor<Entry<HK, HV>> scan(ScanOptions options) {
	return ops.scan(getKey(), options);
}