Category: memcached

Khóa học miễn phí Memcached – Set Data nhận dự án làm có lương
Memcached – Set Data
Memcached set command is used to set a new value to a new or existing key.

Syntax

The basic syntax of Memcached set command is as shown below −

set key flags exptime bytes [noreply] value

The keywords in the syntax are as described below −

key − It is the name of the key by which data is stored and retrieved from Memcached.

flags − It is the 32-bit unsigned integer that the server stores with the data provided by the user, and returns along with the data when the item is retrieved.

exptime − It is the expiration time in seconds. 0 means no delay. If exptime is more than 30 days, Memcached uses it as UNIX timestamp for expiration.

bytes − It is the number of bytes in the data block that needs to be stored. This is the length of the data that needs to be stored in Memcached.

noreply (optional) – It is a parameter that informs the server not to send any reply.

value − It is the data that needs to be stored. The data needs to be passed on the new line after executing the command with the above options.

Output

The output of the command is as shown below −

STORED

STORED indicates success.

ERROR indicates incorrect syntax or error while saving data.

Example

In the following example, we use tutorialspoint as the key and set value Memcached in it with an expiration time of 900 seconds.

set tutorialspoint 0 900 9 memcached STORED get tutorialspoint VALUE tutorialspoint 0 9 Memcached END

Set Data Using Java Application

To set a key in Memcached server, you need to use Memcached set method.

Example

import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { // Connecting to Memcached server on localhost MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server sucessfully"); System.out.println("set status:"+mcc.set("tutorialspoint", 900, "memcached").done); // Get value from cache System.out.println("Get from Cache:"+mcc.get("tutorialspoint")); } }

Output

On compiling and executing the program, you get to see the following output −

Connection to server successfully set status:true Get from Cache:memcached

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August 17, 2024
Khóa học miễn phí Memcached – Add Data nhận dự án làm có lương
Memcached – Add Data
Memcached add command is used to set a value to a new key. If the key already exists, then it gives the output NOT_STORED.

Syntax

The basic syntax of Memcached add command is as shown below −
```
add key flags exptime bytes [noreply]
value
```
The keywords in the syntax are as described below −
- key − It is the name of the key by which data is stored and retrieved from Memcached.
- flags − It is the 32-bit unsigned integer that the server stores with the data provided by the user, and returns along with the data when the item is retrieved.
- exptime − It is the expiration time in seconds. 0 means no delay. If exptime is more than 30 days, Memcached uses it as a UNIX timestamp for expiration.
- bytes − It is the number of bytes in the data block that needs to be stored. This is the length of the data that needs to be stored in Memcached.
- noreply (optional) − It is a parameter that informs the server not to send any reply.
- value − It is the data that needs to be stored. The data needs to be passed on the new line after executing the command with the above options.
Output

The output of the command is as shown below −
```
STORED
```
- STORED indicates success.
- NOT_STORED indicates the data is not stored in Memcached.
Example

In the following example, we use ‘key’ as the key and add the value Memcached in it with an expiration time of 900 seconds.
```
add key 0 900 9
memcached
STORED
get key
VALUE key 0 9
Memcached
END
```
Failure Output
```
add key 0 900 5
redis
NOT_STORED
```
Add Data Using Java Application

To add data in a Memcached server, you need to use the Memcached add method.

Example
```
import net.spy.memcached.MemcachedClient;
public class MemcachedJava {
   public static void main(String[] args) {

      // Connecting to Memcached server on localhost
      MemcachedClient mcc = new MemcachedClient(new
      InetSocketAddress("127.0.0.1", 11211));
      System.out.println("Connection to server successful");
      System.out.println("add status:"+mcc.add("tutorialspoint", 900, "redis").done);
      System.out.println("add status:"+mcc.add("tp", 900, "redis").done);

      // Get value from cache
      System.out.println("Get from Cache tp:"+mcc.get("tp"));
   }
}
```
Output

On compiling and executing the program, you get to see the following output −
```
Connection to server successful
add status:false
add status:true
Get from Cache tp:redis
```
Khóa học lập trình tại Toidayhoc vừa học vừa làm dự án vừa nhận lương: Khóa học lập trình nhận lương tại trung tâm Toidayhoc

August 17, 2024
Khóa học miễn phí Memcached – Append Data nhận dự án làm có lương
Memcached – Append Data
Memcached append command is used to add some data in an existing key. The data is stored after the existing data of the key.

Syntax

The basic syntax of Memcached append command is as shown below −

append key flags exptime bytes [noreply] value

The keywords in the syntax are as described below−

key − It is the name of the key by which data is stored and retrieved from Memcached.

flags − It is the 32-bit unsigned integer that the server stores with the data provided by the user, and returns along with the data when the item is retrieved.

exptime − It is the expiration time in seconds. 0 means no delay. If exptime is more than 30 days, Memcached uses it as a UNIX timestamp for expiration.

bytes − It is the number of bytes in the data block that needs to be stored. This is the length of the data that needs to be stored in Memcached.

noreply (optional) − It is a parameter that informs the server not send any reply.

value − It is the data that needs to be stored. The data needs to be passed on the new line after executing the command with the above options.

Output

The output of the command is as shown below −

STORED

STORED indicates success.

NOT_STORED indicates the key does not exist in the Memcached server.

CLIENT_ERROR indicates error.

Example

In the following example, we try to add some data in a key that does not exist. Hence, Memcached returns NOT_STORED. After this, we set one key and append data into it.

append tutorials 0 900 5 redis NOT_STORED set tutorials 0 900 9 memcached STORED get tutorials VALUE tutorials 0 14 memcached END append tutorials 0 900 5 redis STORED get tutorials VALUE tutorials 0 14 memcachedredis END

Append Data Using Java Application

To append data in a Memcached server, you need to use the Memcached append method.

Example

import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { // Connecting to Memcached server on localhost MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful"); System.out.println("set status:"+mcc.set("tutorialspoint", 900, "memcached").isDone()); // Get value from cache System.out.println("Get from Cache:"+mcc.get("tutorialspoint")); // now append some data into existing key System.out.println("Append to cache:"+mcc.append("tutorialspoint", "redis").isDone()); // get the updated key System.out.println("Get from Cache:"+mcc.get("tutorialspoint")); } }

Output

On compiling and executing the program, you get to see the following output −

Connection to server successful set status:true Get from Cache:memcached Append to cache:true Get from Cache:memcachedredis

Khóa học lập trình tại Toidayhoc vừa học vừa làm dự án vừa nhận lương: Khóa học lập trình nhận lương tại trung tâm Toidayhoc

August 17, 2024