java - 如何从数据库获取 spring-logback 的路径

Question

我最近开始从事 Spring boot 项目。这里所有应用程序或环境级别的属性都存储在数据库(Oracle)中。这包括应用程序中使用的所有 URL、路径等。

这些属性在启动时获取，存储在静态映射中，然后在整个应用程序中使用(也许这个想法是客户端可以更新数据库中的任何属性并重新启动特定环境，并且一切都应该正常工作)。

这工作得很好，接受这样一个事实:服务器日志的路径仍然是从 logging.properties 文件中选取的。日志记录是通过 spring-logback xml 配置完成的。

我相信日志记录是 Spring boot 甚至在数据库连接之前完成的第一件事，因此很难从数据库获取路径然后将其提供给 logback 文件。

是否有任何可能的方法来配置日志记录，以便也可以从数据库中获取日志的路径。

Answer 1

我认为您需要将 application.properties 文件数据存储到数据库中。您可以对此进行配置，如果您选择将 appication.properties 存储到数据库中，则可以使用数据库附加程序来完成此操作。

<configuration  debug="true">

  <appender name="DB" class="ch.qos.logback.classic.db.DBAppender">
     <connectionSource class="ch.qos.logback.core.db.DataSourceConnectionSource">

       <dataSource class="${dataSourceClass}">
         <!-- Joran cannot substitute variables
         that are not attribute values. Therefore, we cannot
         declare the next parameter like the others. 
         -->
         <param name="${url-key:-url}" value="${url_value}"/>
         <serverName>${serverName}</serverName>
         <databaseName>${databaseName}</databaseName>
       </dataSource>

       <user>${user}</user>
       <password>${password}</password>
     </connectionSource>
  </appender>

  <root level="INFO">
    <appender-ref ref="DB" />
  </root>  
</configuration>

但是需要从数据库中获取数据，然后你可以使用下面的代码。

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.HashMap;
import java.util.Map;

import javax.sql.DataSource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;

public class ReadDBPropertiesInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    private static final Logger LOG = LoggerFactory.getLogger(ReadDBPropertiesInitializer.class);

    /**
     * Name of the custom property source added by this post processor class
     */
    private static final String PROPERTY_SOURCE_NAME = "databaseProperties";

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {

        ConfigurableEnvironment configEnv = ((ConfigurableEnvironment) applicationContext.getEnvironment());

        LOG.info("Load properties from database");

        Map<String, Object> propertySource = new HashMap<>();

        try {

            final String url = getEnv(configEnv, "spring.datasource.url");

            String driverClassName = getProperty(configEnv, "spring.datasource.driver-class-name");

            final String username = getEnv(configEnv, "spring.datasource.username");
            final String password = getEnv(configEnv, "spring.datasource.password");

            DataSource ds = DataSourceBuilder.create().url(url).username(username).password(password)
                    .driverClassName(driverClassName).build();

            // Fetch all properties
            PreparedStatement preparedStatement = ds.getConnection()
                    .prepareStatement("SELECT config_key as name, config_value as value, config_label as label FROM TB_CONFIGURATION");

            ResultSet rs = preparedStatement.executeQuery();

            // Populate all properties into the property source
            while (rs.next()) {             
                final String propName = rs.getString("name");
                final String propValue = rs.getString("value");
                final String propLabel = rs.getString("label");
                LOG.info(String.format("Property: %s | Label: %s", propName, propLabel));
                LOG.info(String.format("Value: %s", propValue));
                propertySource.put(propName, propValue);
            }

            // Create a custom property source with the highest precedence and add it to
            // Spring Environment
            applicationContext.getEnvironment().getPropertySources()
                    .addFirst(new MapPropertySource(PROPERTY_SOURCE_NAME, propertySource));

        } catch (Exception e) {
            throw new RuntimeException("Error fetching properties from db");
        }

    }

    private String getEnv(ConfigurableEnvironment configEnv, final String property) {
        MutablePropertySources propertySources = configEnv.getPropertySources();
        PropertySource<?> appConfigProp = propertySources.get("applicationConfigurationProperties");
        return System.getenv().get(((String) appConfigProp.getProperty(property)).replace("${", "").replace("}", ""));
    }

    private String getProperty(ConfigurableEnvironment configEnv, final String property) {
        MutablePropertySources propertySources = configEnv.getPropertySources();
        PropertySource<?> appConfigProp = propertySources.get("applicationConfigurationProperties");
        return (String) appConfigProp.getProperty(property);
    }