本文僅為個人記錄，方便以後查閱。

用途

專案中使用了 dubbo，註冊中心使用的 zookeeper，使用 zookeeper 實現了一個簡單的分散式鎖（依賴 curator），因為配置檔案存在 dubbo.registry 配置，為了直接使用這個地址來建立分散式鎖，寫了一個簡單的方法來提取 zookeeper 地址。

效果

dubbo.registry 有多種配置方式，支援所有情況，下面是常見的例子和提取結果：

zookeeper://localhost:2181
zookeeper://localhost:2181?client=zkclient
zookeeper://localhost:2181?backup=localhost:2182,localhost:2183
zookeeper://localhost:2181?client=zkclient&backup=localhost:2182,localhost:2183
------------結果------------
Optional[localhost:2181]
Optional[localhost:2181]
Optional[localhost:2181,localhost:2182,localhost:2182]
Optional[localhost:2181,localhost:2183,localhost:2183]

程式碼

import java.util.Optional;

public class ZookeeperURL {
    public static final String PREFIX = "zookeeper://";
    public static final String BACKUP = "backup=";

    public static Optional<String> convertDubboRegistryToZookeeperURL(String dubboRegistry){
        StringBuilder zookeeperURL =
 
 new StringBuilder();
        if(dubboRegistry != null && dubboRegistry.startsWith(PREFIX)){
            dubboRegistry = dubboRegistry.substring(PREFIX.length());
            int index = dubboRegistry.indexOf("?");
            if(index > 0){
                zookeeperURL.append(dubboRegistry.
 
substring(0, index));
                dubboRegistry = dubboRegistry.substring(index + 1);
                String[] dubboRegistries = dubboRegistry.split("&");
                for (int i = 0; i < dubboRegistries.length; i++) {
                    if(dubboRegistries[i].startsWith(BACKUP)){
                        String[] backups = dubboRegistries[i].substring(BACKUP.length()).split(",");
                        for (int j = 0; j < backups.length; j++) {
                            zookeeperURL.append(",").append(backups[i]);
                        }
                    }
                }
            } else {
                zookeeperURL.append(dubboRegistry);
            }
            return Optional.of(zookeeperURL.toString());
        }
        return Optional.empty();
    }

    public static void main(String[] args) {
        System.out.println(convertDubboRegistryToZookeeperURL("zookeeper://localhost:2181"));
        System.out.println(convertDubboRegistryToZookeeperURL("zookeeper://localhost:2181?client=zkclient"));
        System.out.println(convertDubboRegistryToZookeeperURL("zookeeper://localhost:2181?backup=localhost:2182,localhost:2183"));
        System.out.println(convertDubboRegistryToZookeeperURL("zookeeper://localhost:2181?client=zkclient&backup=localhost:2182,localhost:2183"));
    }

}