import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

public class PropertiesDemo {
    
    public static void main(String[] args) {
        Properties properties = new Properties();
        
        // 從文件加載配置
        try (FileInputStream fis = new FileInputStream("config.properties")) {
            properties.load(fis);
            
            // 讀取配置項（提供默認(rèn)值）
            String dbUrl = properties.getProperty("database.url", "jdbc:mysql://localhost:3306/mydb");
            String username = properties.getProperty("database.username", "root");
            String password = properties.getProperty("database.password", "");
            
            System.out.println("Database URL: " + dbUrl);
            System.out.println("Username: " + username);
            System.out.println("Password: " + password);
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.JsonNode;
import java.io.File;
import java.io.IOException;

public class JacksonConfigDemo {
    
    // 配置類
    public static class AppConfig {
        private String name;
        private DatabaseConfig database;
        private boolean debugMode;
        private List<String> supportedTypes;
        
        // Getters and setters
        // ...
    }
    
    public static class DatabaseConfig {
        private String url;
        private String username;
        private String password;
        private int maxConnections;
        
        // Getters and setters
        // ...
    }
    
    public static void main(String[] args) {
        ObjectMapper mapper = new ObjectMapper();
        
        try {
            // 1. 使用對象綁定方式讀取配置
            AppConfig config = mapper.readValue(new File("config.json"), AppConfig.class);
            
            System.out.println("App Name: " + config.name);
            System.out.println("Debug Mode: " + config.debugMode);
            System.out.println("Database URL: " + config.database.url);
            
            // 2. 使用樹模型方式讀取配置
            JsonNode rootNode = mapper.readTree(new File("config.json"));
            String appName = rootNode.get("name").asText();
            boolean debugMode = rootNode.get("debugMode").asBoolean();
            JsonNode databaseNode = rootNode.get("database");
            String dbUrl = databaseNode.get("url").asText();
            
            // 3. 更新配置并保存
            config.debugMode = !config.debugMode;
            config.database.maxConnections = 20;
            mapper.writerWithDefaultPrettyPrinter()
                  .writeValue(new File("updated-config.json"), config);
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import org.apache.commons.configuration2.Configuration;
import org.apache.commons.configuration2.builder.fluent.Configurations;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.JSONConfiguration;
import org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.fluent.Parameters;

public class CommonsConfigDemo {
    
    public static void main(String[] args) {
        try {
            // 1. 簡單用法：加載屬性文件
            Configurations configs = new Configurations();
            Configuration propConfig = configs.properties("app.properties");
            
            String appName = propConfig.getString("app.name", "MyApp");
            int maxThreads = propConfig.getInt("app.max-threads", 10);
            boolean debugMode = propConfig.getBoolean("app.debug", false);
            
            System.out.println("Application Name: " + appName);
            System.out.println("Max Threads: " + maxThreads);
            System.out.println("Debug Mode: " + debugMode);
            
            // 2. 加載并處理JSON配置
            Parameters params = new Parameters();
            FileBasedConfigurationBuilder<JSONConfiguration> builder =
                new FileBasedConfigurationBuilder<>(JSONConfiguration.class)
                    .configure(params.fileBased()
                        .setFileName("config.json"));
            
            Configuration jsonConfig = builder.getConfiguration();
            String dbUrl = jsonConfig.getString("database.url");
            String[] supportedFormats = jsonConfig.getStringArray("app.supported-formats");
            
            System.out.println("Database URL: " + dbUrl);
            System.out.println("Supported Formats:");
            for (String format : supportedFormats) {
                System.out.println("- " + format);
            }
            
            // 3. 組合多個配置源
            Configuration compositeConfig = new CombinedConfiguration();
            ((CombinedConfiguration) compositeConfig).addConfiguration(propConfig);
            ((CombinedConfiguration) compositeConfig).addConfiguration(jsonConfig);
            
        } catch (ConfigurationException e) {
            e.printStackTrace();
        }
    }
}

import org.yaml.snakeyaml.Yaml;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Map;

public class SnakeYAMLDemo {
    
    public static void main(String[] args) {
        Yaml yaml = new Yaml();
        
        try {
            // 1. 加載YAML文件到Map
            Map<String, Object> config = yaml.load(new FileInputStream("application.yml"));
            
            // 訪問嵌套配置
            Map<String, Object> server = (Map<String, Object>) config.get("server");
            int port = (int) server.get("port");
            
            Map<String, Object> spring = (Map<String, Object>) config.get("spring");
            Map<String, Object> profiles = (Map<String, Object>) spring.get("profiles");
            
            System.out.println("Server Port: " + port);
            System.out.println("Active Profile: " + profiles.get("active"));
            
            // 2. 直接映射到自定義類
            ServerConfig serverConfig = yaml.loadAs(
                new FileInputStream("server.yml"), ServerConfig.class);
            System.out.println("Max Threads: " + serverConfig.getMaxThreads());
            
            // 3. 處理多文檔YAML
            Iterable<Object> documents = yaml.loadAll(new FileInputStream("multi-doc.yml"));
            for (Object document : documents) {
                System.out.println("--- Document ---");
                System.out.println(document);
            }
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    
    // 配置類
    public static class ServerConfig {
        private int port;
        private int maxThreads;
        private boolean ssl;
        
        // Getters and setters
        // ...
        
        public int getMaxThreads() {
            return maxThreads;
        }
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;

@SpringBootApplication
@EnableConfigurationProperties(ServerProperties.class)
public class SpringConfigDemo {
    
    public static void main(String[] args) {
        SpringApplication.run(SpringConfigDemo.class, args);
    }
    
    @Bean
    public void displayConfig(ServerProperties serverProps) {
        System.out.println("Server Port: " + serverProps.getPort());
        System.out.println("Server Address: " + serverProps.getAddress());
        System.out.println("Max Threads: " + serverProps.getMaxThreads());
        System.out.println("SSL Enabled: " + serverProps.isSslEnabled());
    }
}

@Component
@ConfigurationProperties(prefix = "server")
class ServerProperties {
    
    @Min(1000)
    @Max(65535)
    private int port = 8080;
    
    @NotEmpty
    private String address = "localhost";
    
    private int maxThreads = 200;
    
    private boolean sslEnabled = false;
    
    // Getters and setters
    // ...
}

server:
  port: 9090
  address: 0.0.0.0
  max-threads: 100
  ssl-enabled: true

import org.ini4j.Ini;
import org.ini4j.Profile.Section;
import java.io.File;
import java.io.IOException;

public class Ini4jDemo {
    
    public static void main(String[] args) {
        try {
            // 1. 讀取INI文件
            Ini ini = new Ini(new File("config.ini"));
            
            // 2. 訪問節(jié)和鍵值
            Section databaseSection = ini.get("database");
            String url = databaseSection.get("url");
            String username = databaseSection.get("username");
            String password = databaseSection.get("password");
            
            System.out.println("Database URL: " + url);
            System.out.println("Username: " + username);
            
            // 3. 帶類型轉(zhuǎn)換的值獲取
            int port = databaseSection.get("port", int.class);
            boolean ssl = databaseSection.get("ssl", boolean.class);
            
            System.out.println("Port: " + port);
            System.out.println("SSL: " + ssl);
            
            // 4. 修改配置
            databaseSection.put("max_connections", 20);
            databaseSection.put("timeout", 30);
            
            // 5. 添加新節(jié)
            Section loggingSection = ini.add("logging");
            loggingSection.put("level", "INFO");
            loggingSection.put("file", "/var/log/app.log");
            
            // 6. 保存配置
            ini.store(new File("updated-config.ini"));
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

; Database configuration
[database]
url=jdbc:mysql://localhost:3306/mydb
username=root
password=secret
port=3306
ssl=true

; Application settings
[app]
name=MyApplication
version=1.0.0
debug=false

import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;
import com.typesafe.config.ConfigValue;

import java.util.Map;

public class TypesafeConfigDemo {
    
    public static void main(String[] args) {
        // 1. 加載配置（自動查找application.conf, application.json, application.properties）
        Config config = ConfigFactory.load();
        
        // 2. 獲取嵌套路徑的配置
        String dbUrl = config.getString("database.url");
        int dbPoolSize = config.getInt("database.connection-pool.size");
        
        // 3. 使用路徑替換和引用
        String appLogDir = config.getString("app.log-dir");
        String accessLogPath = config.getString("app.log-paths.access-log");
        // 在application.conf中可以這樣定義: 
        // app.log-paths.access-log = ${app.log-dir}"/access.log"
        
        // 4. 轉(zhuǎn)換為Java Map
        Config dbConfig = config.getConfig("database");
        Map<String, Object> dbMap = dbConfig.root().unwrapped();
        
        // 5. 獲取所有配置鍵
        for (Map.Entry<String, ConfigValue> entry : config.entrySet()) {
            System.out.println(entry.getKey() + " = " + entry.getValue().render());
        }
        
        // 6. 合并配置
        Config defaultConfig = ConfigFactory.parseResources("defaults.conf");
        Config customConfig = ConfigFactory.parseFile(new File("custom.conf"));
        Config mergedConfig = customConfig.withFallback(defaultConfig).resolve();
        
        // 7. 類型安全的時間和內(nèi)存大小配置
        java.time.Duration timeout = config.getDuration("app.timeout");
        long maxMemory = config.getBytes("app.max-memory");
        
        System.out.println("Timeout: " + timeout.getSeconds() + " seconds");
        System.out.println("Max Memory: " + (maxMemory / (1024 * 1024)) + " MB");
    }
}