Java读取配置文件，如果外部文件不存在，则从jar内读取

Java读取配置文件

如果外部文件不存在，则从jar内读取，开发时配置文件路径：src/main/resources

// package me.muphy.util;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.*;

public class PropertyUtils {
	
    public static class IRefresher {
        void refresh();
    }

    private final static Logger log = LoggerFactory.getLogger(PropertyUtils.class);
    public static final String filename = "nuonuo.properties";
    private static final Map<String, Map<String, String>> propertiesMap = new HashMap<>();
    private static final List<IRefresher> propertyConfigs = new ArrayList<>();

    public static void addRefresh(IRefresher config) {
        if (config == null) {
            return;
        }
        for (IRefresher propertyConfig : propertyConfigs) {
            if (config == propertyConfig) {
                return;
            }
            if (Objects.equals(config.fileName(), propertyConfig.fileName())) {
                propertyConfigs.remove(propertyConfig);
            }
        }
        propertyConfigs.add(config);
    }

    public static Map<String, String> getProperties() {
        return getProperties(filename);
    }

    public static String getProperty(String key) {
        if (key == null) {
            return null;
        }
        Map<String, String> properties = getProperties();
        String val = properties.get(key);
        try {
            log.debug("读取属性，key：" + key + "，value：" + val);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return val;
    }

    public static String setProperty(String key, String value) {
        if (key == null) {
            return null;
        }
        Map<String, String> properties = getProperties();
        properties.put(key, value);
        refresh(filename, false);
        return properties.get(key);
    }

    public static Map<String, String> refresh(String filename) {
        return refresh(filename, true);
    }

    private static Map<String, String> refresh(String filename, boolean reloadFile) {
        Map<String, String> properties = getProperties(filename, reloadFile);
        for (IRefresher propertyConfig : propertyConfigs) {
            if (Objects.equals(propertyConfig.fileName(), filename)) {
                try {
                    propertyConfig.refresh();
                } catch (Exception e) {
                    log.error(e.getMessage(), e);
                }
            }
        }
        return properties;
    }

    public static Map<String, String> getProperties(String filename) {
        return getProperties(filename, false);
    }

    private static Map<String, String> getProperties(String filename, boolean refresh) {
        if (StringUtils.isEmpty(filename)) {
            throw new RuntimeException("配置文件不能为空！");
        }
        if (!refresh && propertiesMap.containsKey(filename)) {
            return propertiesMap.get(filename);
        }
        Map<String, String> map = new HashMap<>();
        propertiesMap.put(filename, map);
        Properties properties = new Properties();
        File externalFile = new File(filename);
        if (externalFile.exists() && externalFile.isFile()) {
            try (FileInputStream inputStream = new FileInputStream(externalFile)) {
                properties.load(inputStream);
                if (!filename.contains("log.properties")) {
                    log.debug("加载了外部的配置文件: " + externalFile.getAbsolutePath());
                }
            } catch (IOException e) {
                throw new RuntimeException("读取外部配置文件【" + filename + "】失败！", e);
            }
        } else {
            try (InputStream inputStream = NuoNuoConfiguration.class.getClassLoader().getResourceAsStream(filename)) {
                if (inputStream == null) {
                    try (InputStream is = NuoNuoConfiguration.class.getClassLoader().getResourceAsStream("default-" + filename)) {
                        if (is == null) {
                            throw new RuntimeException("找不到配置文件【" + filename + "】！请确保文件位于类路径的根目录下或JAR同级目录。");
                        }
                        properties.load(is);
                        if (!filename.contains("log.properties")) {
                            log.debug("加载了JAR内部的默认配置文件。");
                        }
                    } catch (IOException e) {
                        throw new RuntimeException("读取配置文件【" + filename + "】失败！", e);
                    }
                } else {
                    properties.load(inputStream);
                    if (!filename.contains("log.properties")) {
                        log.debug("加载了JAR内部的配置文件。");
                    }
                }
            } catch (IOException e) {
                throw new RuntimeException("读取配置文件【" + filename + "】失败！", e);
            }
        }
        for (Map.Entry<Object, Object> entry : properties.entrySet()) {
            String key = entry.getKey().toString();
            String value = properties.getProperty(key);
            if (value != null) {
                map.put(key, new String(value.getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8));
            }
        }
        log.debug("加载到配置：" + JsonUtils.toJSONString(map));
        return map;
    }
}