Pomelo Lee workspace

#ignore these files
*.class
classes/
target/
build/

public class Singleton {
    private static Singleton instance;
    private Singleton (){}
    public static Singleton getInstance() {
     if (instance == null) {
         instance = new Singleton();
     }
     return instance;
    }
}

public static synchronized Singleton getInstance() {
    if (instance == null) {
        instance = new Singleton();
    }
    return instance;
}

public static Singleton getSingleton() {
    if (instance == null) {                         //Single Checked
        synchronized (Singleton.class) {
            if (instance == null) {                 //Double Checked
                instance = new Singleton();       //非原子操作
            }
        }
    }
    return instance ;
}

public class Singleton {
    private volatile static Singleton instance; //这里为 volatile
    private Singleton (){}
    public static Singleton getSingleton() {
        if (instance == null) {                         
            synchronized (Singleton.class) {
                if (instance == null) {       
                    instance = new Singleton();
                }
            }
        }
        return instance;
    }  
}

Sets the root directory for requests. For example, with the following configuration
location /i/ {
    root /data/w3;
}
The /data/w3/i/top.gif file will be sent in response to the “/i/top.gif” request

Defines a replacement for the specified location. For example, with the following configuration
location /i/ {
    alias /data/w3/images/;
}
on request of “/i/top.gif”, the file /data/w3/images/top.gif will be sent.

location /api/v1/upload {  
     alias /home/v1/upload/;  
}

java.sql.SQLException: Incorrect string value: ‘\xF0\x9F\x92\x94’ for column ‘name’ at row 1 
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073) 
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3593) 
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3525) 
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986) 
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140) 
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2620) 
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1662) 
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1581)

[mysqld] 
character-set-client-handshake = FALSE 
character-set-server = utf8mb4 
collation-server = utf8mb4_unicode_ci 
init_connect='SET NAMES utf8mb4'
 
[client] 
default-character-set = utf8mb4 
[mysql] 
default-character-set = utf8mb4

SHOW VARIABLES WHERE Variable_name LIKE 'character_set_%' OR Variable_name LIKE 'collation%';
 
Variable_name	Value
character_set_client	utf8mb4
character_set_connection	utf8mb4
character_set_database	utf8mb4
character_set_filesystem	binary
character_set_results	utf8mb4
character_set_server	utf8mb4
character_set_system	utf8
collation_connection	utf8mb4_unicode_ci
collation_database	utf8mb4_unicode_ci
collation_server	utf8mb4_unicode_ci
collation_connection 、collation_database 、collation_server是什么没关系。
 
但必须保证
 
系统变量	描述
character_set_client	(客户端来源数据使用的字符集)
character_set_connection	(连接层字符集)
character_set_database	(当前选中数据库的默认字符集)
character_set_results	(查询结果字符集)
character_set_server	(默认的内部操作字符集)
这几个变量必须是utf8mb4。

 require_once("../../../wp-config.php");
 wp_set_auth_cookie($wpuid);
 wp_set_current_user($wpuid);
 do_action('wp_login');

package main
 
import (
    "fmt"
    "time"
)
 
func main() {
    i := 10000
    for j := 0; j < 3; j++ {
        // 使用多协程处理，其中可以预见的是除数为0会抛出异常
        go divide(i, j)
    }
 
    // 为了保证前面线程运行完，这里休眠一下
    for {
        time.Sleep(1 * time.Second)
    }
}
 
func divide(i, j int) {
    // 定义recover方法，在后面程序出现异常的时候就会捕获
    defer func() {
        if r := recover(); r != nil {
            // 这里可以对异常进行一些处理和捕获
            fmt.Println("Recovered:", r)
        }
    }()
 
    fmt.Println(i / j)
}

./letsencrypt-auto renew --email service@i5a6.com --agree-tos --force-renewal

./letsencrypt-auto renew -v --agree-tos --force-renewal

./letsencrypt-auto --help