Java Operation Redis described in detail
- 2020-11-18 06:14:22
- OfStack
1. Introduction
Redis is an open source (BSD licensed), in-memory ES5en-ES6en storage system that can be used as a database, cache, and messaging middleware.
2. Operation of key
The first step is to establish the connection Jedis jedis = new Jedis("127.0.0.1", 6379), then you can operate on string, set, zset, hash.
// right key The test of
public void keyTest() {
System.out.println(jedis.flushDB());
// Empty data
System.out.println(jedis.echo("hello"));
// print hello
System.out.println(jedis.exists("foo"));
// judge key If there is a
jedis.set("key1", "values1");
jedis.set("key2", "values2");
System.out.println(jedis.exists("key1"));
// judge key If there is a
String randomKey = jedis.randomKey();
// choose 1 A random key
System.out.println("randomKey For the : " + randomKey);
jedis.expire("key1", 60);
// Time to live
System.out.println(jedis.pttl("key1"));
// The rest of your survival time
// remove key Expiration time
jedis.persist("key1");
// To obtain key The type of , "string", "list", "set" "none" none said key There is no
System.out.println("type The type of : " + jedis.type("key1"));
//key The type of
// export key The value of the
String value = jedis.get("key1");
System.out.println(value);
// will key rename
jedis.renamenx("key1", "keytest");
System.out.println("key1 If there is a : " + jedis.exists("key1"));
// To determine whether there is
System.out.println("keytest If there is a : " + jedis.exists("keytest"));
// To determine whether there is
// Query-Matched key
// KEYS * Matches all in the database key .
// KEYS h?llo matching hello . hallo and hxllo And so on.
// KEYS h*llo matching hllo and heeeeello And so on.
// KEYS h[ae]llo matching hello and hallo But it doesn't match hillo .
// Special symbol \ Separated.
Set<string> set = jedis.keys("k*");
// Get all relevant key keys methods
System.out.println(set);
jedis.del("key1");
// delete key del methods
System.out.println(jedis.exists("key1"));
}3. String data type
set mystr "hello world!" // Set the string type
get mystr // Read string type
Perform numeric manipulation on a string
127.0.0.1:6379> set mynum "2"
OK
127.0.0.1:6379> get mynum
"2"
127.0.0.1:6379> incr mynum
(integer) 3
127.0.0.1:6379> get mynum
"3"The operation code of Java is:
// right string Operational test
public void stringTest() {
jedis.set("hello", "hello");
//set
System.out.println(jedis.get("hello"));
//get
// use append Add to the string
jedis.append("hello", " world");
// additional append methods
System.out.println(jedis.get("hello"));
// set Overwrite string
jedis.set("hello", "123");
System.out.println(jedis.get("hello"));
// Set expiration time
jedis.setex("hello2", 2, "world2");
System.out.println(jedis.get("hello2"));
try {
Thread.sleep(3000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(jedis.get("hello2"));
// 1 Add multiple times key-value right
jedis.mset("a", "1", "b", "2");
// To obtain a and b the value
List<string> valus = jedis.mget("a", "b");
System.out.println(valus);
// Batch delete
jedis.del("a", "b");
System.out.println(jedis.exists("a"));
System.out.println(jedis.exists("b"));
}4. List data type
lists in redis is not an array on the underlying implementation, but a linked list.
Series 1 Operations: RPUSH, LPUSH, LLEN, LRANGE, LPOP and RPOP.
We can use LPUSH to insert a new element to the left of lists, RPUSH to insert a new element to the right of lists, and LRANGE to specify a range from lists to extract elements.
// new 1 a list called mylist , and inserts elements at the head of the list "1"
127.0.0.1:6379> lpush mylist "1"
// Returns the current mylist Number of elements in
(integer) 1
// in mylist Insert element on the right "2"
127.0.0.1:6379> rpush mylist "2"
(integer) 2
// in mylist Insert element to the left "0"
127.0.0.1:6379> lpush mylist "0"
(integer) 3
// list mylist From the number in 0 The serial number 1 The elements of the
127.0.0.1:6379> lrange mylist 0 1
1) "0"
2) "1"
// list mylist From the number in 0 To the bottom first 1 An element
127.0.0.1:6379> lrange mylist 0 -1
1) "0"
2) "1"
3) "2"The operation code of Java is:
public void listTest() {
String key = "mylist";
jedis.del(key);
// Let me delete that
// Queue add element
jedis.rpush(key, "aaaa");
jedis.rpush(key, "aaaa");
jedis.rpush(key, "bbbb");
jedis.rpush(key, "cccc");
jedis.rpush(key, "cccc");
// The queue length
System.out.println("lenth: " + jedis.llen(key));
// Print queue from index 0 Here we go, to the bottom 1 Number of (all elements)
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// The index for 1 The elements of the
System.out.println("index of 1: " + jedis.lindex(key, 1));
// Set the queue 1 The value of the element, when index It returns when it goes out of range 1 a error .
jedis.lset(key, 1, "aa22");
System.out.println("index of 1: " + jedis.lindex(key, 1));
// Join the queue from the right side of the queue 1 An element
jedis.rpush(key, "-2", "-1");
// First, -2 After, -1 In the queue
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// Join the queue from the left of the queue 1 Three or more elements
jedis.lpush(key, "second element", "first element");
// First, second
// element After, first
// elementF In the queue
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// Get out of the queue on the right 1 An element
System.out.println(jedis.rpop(key));
// Get out of the queue on the left 1 An element
System.out.println(jedis.lpop(key));
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// count > 0: The value removed from beginning to end is value The elements, count Is the number of removals.
// count < 0: Remove value from tail to head value The elements, count Is the number of removals.
// count = 0: Remove all values of zero value The element.
jedis.lrem(key, 1, "cccc");
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// The element on the far right will also be included. if start than list When the index is large, it returns 1 An empty list.
// if stop than list When the actual tail is larger, Redis Think of it as the last 1 The subscripts of the elements.
System.out.println(jedis.lrange(key, 0, 2));
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
// Deletes elements outside the interval
System.out.println(jedis.ltrim(key, 0, 2));
System.out.println("all elements: " + jedis.lrange(key, 0, -1));
}5. Set type
The set of redis is an unordered set with no sequence of elements.
Series 1 Operations: SADD, SREM, SISMEMBER, SMEMBERS and SUNION.
Collection-related operations are also abundant, such as adding new elements, deleting existing elements, taking intersection, union, difference set, and so on.
// To the collection myset add 1 A new element "one"
127.0.0.1:6379> sadd myset "one"
(integer) 1
127.0.0.1:6379> sadd myset "two"
(integer) 1
// List the collection myset All the elements in
127.0.0.1:6379> smembers myset
1) "one"
2) "two"
// Judge element 1 Whether or not in the set myset In the back 1 Said there is
127.0.0.1:6379> sismember myset "one"
(integer) 1
// Judge element 3 Whether or not in the set myset In the back 0 Nonexistence
127.0.0.1:6379> sismember myset "three"
(integer) 0
// new 1 A new set yourset
127.0.0.1:6379> sadd yourset "1"
(integer) 1
127.0.0.1:6379> sadd yourset "2"
(integer) 1
127.0.0.1:6379> smembers yourset
1) "1"
2) "2"
// You take the union of two sets
127.0.0.1:6379> sunion myset yourset
1) "1"
2) "one"
3) "2"
4) "two"Java operation code:
public void setTest() {
// Empty data
System.out.println(jedis.flushDB());
String key = "myset1";
String key2 = "myset2";
// Collection add element
jedis.sadd(key, "aaa", "bbb", "ccc");
jedis.sadd(key2, "bbb", "ccc", "ddd");
// Gets the number of elements in the collection
System.out.println(jedis.scard(key));
//the number count of the set
// Gets the intersection of two collections and stores them in 1 A key result set
jedis.sinterstore("destination", key, key2);
System.out.println(jedis.smembers("destination"));
// Gets the union of two sets and stores it in 1 A key result set
jedis.sunionstore("destination", key, key2);
System.out.println(jedis.smembers("destination"));
// key1 In the collection, key2 Collection does not have elements and is stored in 1 A key result set
jedis.sdiffstore("destination", key, key2);
System.out.println(jedis.smembers("destination"));
// Determine if an element is 1 A member of a set
System.out.println(jedis.sismember(key, "aaa"));
// from key Random access from the set 1 An element
System.out.println(jedis.srandmember(key));
// aaa from key Move to the key2 A collection of
jedis.smove(key, key2, "aaa");
System.out.println(jedis.smembers(key));
// Gets the elements in the collection
System.out.println(jedis.smembers(key2));
// Delete and get 1 The members of the set
System.out.println(jedis.spop(key));
// Delete from the collection 1 Three or more elements
jedis.srem(key2, "ccc", "ddd");
System.out.println(jedis.smembers(key2));
}6. Sorted Sets type
We all call the ordered set in redis zsets
// new 1 An ordered set myzset And join 1 An element baidu.com And the ordinal number given to it is 1
127.0.0.1:6379> zadd myzset 1 baidu.com
(integer) 1
// to myzset In the new 1 An element 360.com And the ordinal number given to it is 3
127.0.0.1:6379> zadd myzset 3 360.com
(integer) 1
// to myzset In the new 1 An element google.com And the ordinal number given to it is 2
127.0.0.1:6379> zadd myzset 2 google.com
(integer) 1
// list myzset All of the elements, while listing its serial number, can be seen myzset It's already in order.
127.0.0.1:6379> zrange myzset 0 -1 with scores
1) "baidu.com"
2) "1"
3) "google.com"
4) "2"
5) "360.com"
6) "3"
// List only myzset The elements of the
127.0.0.1:6379> zrange myzset 0 -1
1) "baidu.com"
2) "google.com"
3) "360.com"The operation code of Java is:
public void zsetTest() {
// Empty data
System.out.println(jedis.flushDB());
String key = "mysortset";
Map<string, double=""> scoreMembers = new HashMap<>();
scoreMembers.put("aaa", 1001.0);
scoreMembers.put("bbb", 1002.0);
scoreMembers.put("ccc", 1003.0);
// Add data
jedis.zadd(key, 1004.0, "ddd");
jedis.zadd(key, scoreMembers);
// To obtain 1 The number of members in a sorted set
System.out.println(jedis.zcard(key));
// Returns an ordered collection of members within the specified range 0 Stands for ordered set number 1 Three members, to 1 Stands for ordered set number 2 Members, and so on.
// Negative subscript, so -1 Said the last 1 A member, -2 Is the penultimate value 2 A member of
Set<string> coll = jedis.zrange(key, 0, -1);
System.out.println(coll);
// The inverted collection of returned members in the specified range
coll = jedis.zrevrange(key, 0, -1);
System.out.println(coll);
// Elements in the subscript
System.out.println(jedis.zscore(key, "bbb"));
// Remove elements
System.out.println(jedis.zrem(key, "aaa"));
System.out.println(jedis.zrange(key, 0, -1));
// The number of members within a given range of values
System.out.println(jedis.zcount(key, 1002.0, 1003.0));
}7. Hash type
hashes stores a mapping between strings and string values
// Set up a hash and assign a value
127.0.0.1:6379> HMSET user:001 username antirez password P1pp0 age 34
OK
// List the contents of the hash
127.0.0.1:6379> HGETALL user:001
1) "username"
2) "antirez"
3) "password"
4) "P1pp0"
5) "age"
6) "34"
// Change something in the hash 1 A value
127.0.0.1:6379> HSET user:001 password 12345
(integer) 0
// List the contents of the hash again
127.0.0.1:6379> HGETALL user:001
1) "username"
2) "antirez"
3) "password"
4) "12345"
5) "age"
6) "34"Java operation code:
set mystr "hello world!" // Set the string type
get mystr // Read string type
Perform numeric manipulation on a string
127.0.0.1:6379> set mynum "2"
OK
127.0.0.1:6379> get mynum
"2"
127.0.0.1:6379> incr mynum
(integer) 3
127.0.0.1:6379> get mynum
"3"8. The transaction
A transaction is "a complete action, all or nothing".
Before talking about redis transaction, I would like to introduce four redis instructions, namely MULTI, EXEC, DISCARD and WATCH. These four instructions form the basis of redis's transaction processing.
1.MULTI is used to assemble 1 transaction;
2.EXEC is used to execute 1 transaction;
3.DISCARD is used to cancel 1 transaction;
4.WATCH is used to monitor 1 key, once the key has been changed before the transaction is executed, the transaction is cancelled.
set mystr "hello world!" // Set the string type
get mystr // Read string type
Perform numeric manipulation on a string
127.0.0.1:6379> set mynum "2"
OK
127.0.0.1:6379> get mynum
"2"
127.0.0.1:6379> incr mynum
(integer) 3
127.0.0.1:6379> get mynum
"3"Java operation code is:
set mystr "hello world!" // Set the string type
get mystr // Read string type
Perform numeric manipulation on a string
127.0.0.1:6379> set mynum "2"
OK
127.0.0.1:6379> get mynum
"2"
127.0.0.1:6379> incr mynum
(integer) 3
127.0.0.1:6379> get mynum
"3"Pipe operation Java code:
public void transactionPipelineTest() {
Pipeline p = jedis.pipelined();
// open 1 A pipe
p.set("fool", "bar");
p.zadd("foo", 1, "barowitch");
p.zadd("foo", 0, "barinsky");
p.zadd("foo", 0, "barikoviev");
Response<string> pipeString = p.get("fool");
Response<set<string>> sose = p.zrange("foo", 0, -1);
System.out.println(pipeString);
System.out.println(sose);
p.sync();
// submit
System.out.println("==========");
System.out.println(p.get("fool"));
System.out.println(p.zrange("foo", 0, -1));
int soseSize = sose.get().size();
Set<string> setBack = sose.get();
System.out.println(soseSize);
System.out.println(setBack);
System.out.println(pipeString.get());
}conclusion
That is all the details about Java operation Redis in this article. I hope it will be helpful to you. If there is any deficiency, please let me know. Thank you for your support to this site.