Apollo Config API

該種用法是直接調用Apollo的API獲取某個指定namespace中的單個屬性值。

ConfigService.getAppConfig().getProperty("testkey", "defaulyv1");
ConfigService.getAppConfig("namespace").getProperty("testkey", "defaulyv1");

在Nacos中，可以通過二次封裝支持。示例如下：

    @Autowired 
    NacosConfigPropertiesService nacosConfigPropertiesService;

    private void method(){
        String value=nacosConfigPropertiesService.getProperties("appId1.application.properties", "group","key","defaultValue");
    }

package com.example.demo.service;

import com.alibaba.cloud.nacos.NacosConfigManager;
import com.alibaba.nacos.client.config.common.GroupKey;
import com.alibaba.nacos.client.config.listener.impl.PropertiesListener;
import com.alibaba.nacos.common.utils.StringUtils;
import jakarta.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.io.StringReader;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

@Component
public class NacosConfigPropertiesService {
    
    Map<String, Properties> namespacePropertiesMap = new HashMap<>();
    
    @PostConstruct
    private void postConstruct() {
        try {
            initProperties("appId1.application.properties", "group");
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    @Autowired
    private NacosConfigManager nacosConfigManager;
    
    public String getProperties(final String dataId, final String group, String key, String defaultValue) {
        return namespacePropertiesMap.get(GroupKey.getKey(dataId, group)).getProperty(key, defaultValue);
    }
    
    private void initProperties(final String dataId, final String group) throws Exception {
        
        String aDefault = nacosConfigManager.getConfigService()
                .getConfigAndSignListener(dataId, group, 3000L, new PropertiesListener() {
                    
                    @Override
                    public void innerReceive(Properties properties) {
                        namespacePropertiesMap.put(GroupKey.getKey(dataId, group), properties);
                    }
                });
        if (StringUtils.isBlank(aDefault)) {
            namespacePropertiesMap.put(GroupKey.getKey(dataId, group), new Properties());
        } else {
            Properties properties = new Properties();
            properties.load(new StringReader(aDefault));
            namespacePropertiesMap.put(GroupKey.getKey(dataId, group), properties);
        }
        
    }
    
}

    /**
     * notify listener
     * @param configChangeEvent
     */
    @ApolloConfigChangeListener(interestedKeyPrefixes = {"data."})
    public void apolloNotify(ConfigChangeEvent configChangeEvent) {
        System.out.println(configChangeEvent.changedKeys());
    }
    

    private void apolloNotify(ConfigChangeEvent event) {
        //notify.
        System.out.println(event.getChangeItems());
    }
    
    @PostConstruct
    public void registerListener() throws Exception {
        
       interestedPrefix("appId1.application.properties","default","data.");
    }
  
    private void interestedPrefix(String dataId, String group, String prefix) throws Exception {
        NacosPrefixKeyPropertiesListener prefixKeyPropertiesListener = new NacosPrefixKeyPropertiesListener(prefix) {
            
            @Override
            public void configChanged(ConfigChangeEvent event) {
                notifyOnChange(event);
            }
        };
        
        nacosConfigManager.getConfigService().addListener(dataId, group, prefixKeyPropertiesListener);
    }
    

public abstract class NacosPrefixKeyPropertiesListener extends AbstractConfigChangeListener {
    private String prefix;
    
    public NacosPrefixKeyPropertiesListener(String prefix) {
        this.prefix = prefix;
    }
    
    @Override
    public final void receiveConfigChange(ConfigChangeEvent event) {
        
        Iterator<ConfigChangeItem> iterator = event.getChangeItems().iterator();
        while (iterator.hasNext()) {
            if (!iterator.next().getKey().startsWith(prefix)) {
                iterator.remove();
            }
        }
        
        if (event.getChangeItems().isEmpty()) {
            return;
        }
        configChanged(event);
    }
    
    public abstract void configChanged(ConfigChangeEvent event);
}