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Springboo如何t動態(tài)修改配置文件屬性

更新時間：2023年09月16日 15:04:18 作者：kenick

這篇文章主要介紹了Springboo如何t動態(tài)修改配置文件屬性問題,具有很好的參考價值,希望對大家有所幫助,如有錯誤或未考慮完全的地方,望不吝賜教

Springboot動態(tài)修改配置文件屬性

package com.kenick.config;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
public class CustomApplicationProperties implements EnvironmentPostProcessor {
    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        MutablePropertySources propertySources = environment.getPropertySources();
        // 所有屬性文件名
        String env = "";
        Iterator<PropertySource<?>> iterator = propertySources.iterator();
        System.out.println(" ================== 所有配置文件名 ==================");
        while(iterator.hasNext()){
            PropertySource<?> next = iterator.next();
            String configFileName = next.getName();
            System.out.println(configFileName);
            if(configFileName.contains("application-")){ // spring只會加載當(dāng)前環(huán)境配置
                env = configFileName.split("application-")[1].replace(".properties]", "");
            }
        }
        // 獲取主配置文件
        String mainName = "applicationConfig: [classpath:/application.properties]";
        MapPropertySource propertySource = (MapPropertySource) propertySources.get(mainName);
        Map<String, Object> source = propertySource.getSource();
        System.out.println(" ================== 主配置 ==================");
        source.forEach((k,v) -> {
            System.out.println(k+":"+v.toString());
        });
        // 獲取激活配置文件
        System.out.println("當(dāng)前環(huán)境:" + env);
        String activeName = "applicationConfig: [classpath:/application-" + env + ".properties]";
        MapPropertySource activePropertySource = (MapPropertySource) propertySources.get(activeName);
        Map<String, Object> activeSource = activePropertySource.getSource();
        System.out.println(" ================== 當(dāng)前配置 ==================");
        Map<String, Object> newConfigMap = new HashMap<>();
        activeSource.forEach((k,v) -> {
            System.out.println(k+":"+v.toString());
            newConfigMap.put(k, v.toString()); // value必須要放入String格式
        });
        // 可動態(tài)修改配置
        // newConfigMap.replace("log.custom.test", "E:\\tmp\\logs");
        propertySources.replace(activeName, new MapPropertySource(activeName , newConfigMap));
    }
}

org.springframework.boot.env.EnvironmentPostProcessor=com.kenick.config.CustomApplicationProperties

動態(tài)給springBoot配置增加屬性

有些時候我們要把代碼部署到不同地方，根據(jù)地方不同來辨別要執(zhí)行那些代碼，這時就要把一些配置事先配置到數(shù)據(jù)庫在在容器初始化時讀取對應(yīng)數(shù)據(jù)來執(zhí)行特定需求。

好處可以把一些配置文件配置到數(shù)據(jù)庫。用到@PostConstruct注解與@DependesOn注解

@PostConstruct注解

配置了此注解方法會在調(diào)用構(gòu)造方法后自動被調(diào)用，也可以理解為spring容器初始化的時候執(zhí)行該方法。

實例代碼如下

  @Component
  public class Config3 {
      @Autowired
      private ConfigurableEnvironment environment;
      @PostConstruct
      public void setProvinceCode() {
          MutablePropertySources propertySources = environment.getPropertySources();
          Pattern p = Pattern.compile("^applicationConfig.*");
          for (PropertySource<?> propertySource : propertySources) {
              if (p.matcher(propertySource.getName()).matches()) {
                  Properties properties = new Properties();
                  Map<String, String> map = new HashMap<>();
                  map.put("code","10000000000");
                  properties.putAll(map);
                  PropertiesPropertySource constants = new PropertiesPropertySource("system-config", properties);
                  propertySources.addAfter(propertySource.getName(),constants);
              }
          }
      }
  }

@DependesOn注解

用來表示一個Bean的實例化依賴另一個Bean的實例化

  @DependsOn("config3")
  @Component
  public class Config2 {
      @Value("$[code]")
      private String codeValue;
      public void show() {
          System.out.println(codeValue);
      }
      @Value("$[code]")
      public void setProvinceCode(String codeValue) {
          System.out.println("code:"+codeValue);
      }
  }