Enum 声明字段含义，优雅处理多语言，支持灵活添加

主题

Enum 声明字段含义，优雅处理多语言，支持灵活添加

设计

• 通过枚举定义字段
• 定义一个配置文件，定义实现的语言
• 分别为每种语言配置一套语言翻译，这里利用 Java Resource Bundle 机制

代码依赖

• JDK 5+
• JUnit 4
• fastjson 1.2.66(非必须，仅用在 JUnit 测试中)
• slf4j + logback(非必须，仅用在 JUnit 测试中)

代码实现

FieldDescEnum

package enumsdemo;

import java.util.Map;

/**
 * @author Helly Guo
 * <p>
 * Created on 3/1/20 12:12 PM
 */
public enum FieldDescEnum {
    /**
     * XXX
     */
    FIELD_X("xxx"),
    /**
     * YYY
     */
    FIELD_Y("yyy"),
    /**
     * ZZZ
     */
    FIELD_Z("zzz");

    private final String fieldName;
    private final Map<String, String> descLocales;

    FieldDescEnum(String fieldName) {
        this.fieldName = fieldName;
        this.descLocales = FieldDescPropsUtil.getDescriptionByKey(fieldName);
    }

    public String getFieldName() {
        return fieldName;
    }

    public Map<String, String> getDescLocales() {
        return descLocales;
    }
}

FieldDescPropsUtil

package enumsdemo;

import java.io.IOException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Properties;
import java.util.ResourceBundle;

/**
 * @author Helly Guo
 * <p>
 * Created on 3/1/20 12:12 PM
 */
public final class FieldDescPropsUtil {
    private static final String SUPPORTED_LOCALES_FILE = "support_locales.properties";
    private static final String LOCALES = "locales";
    private static final String FIELD_DESC = "fieldDesc";

    private static final Properties SUPPORTED_LOCALES = new Properties();
    private static final Map<String, ResourceBundle> FIELD_DESC_MAP = new HashMap<>();

    static {
        try {
            SUPPORTED_LOCALES.load(FieldDescPropsUtil.class.getClassLoader().getResourceAsStream(SUPPORTED_LOCALES_FILE));
        } catch (IOException e) {
            throw new RuntimeException("load file failed", e);
        }
        String localesOneLine = SUPPORTED_LOCALES.getProperty(LOCALES);
        String[] locales = localesOneLine.split(",");
        String[] langAndCountry;
        for (String locale : locales) {
            if (locale.indexOf('_') > 0) {
                langAndCountry = locale.split("_");
                FIELD_DESC_MAP.put(locale,
                        ResourceBundle.getBundle(FIELD_DESC,
                                new Locale(langAndCountry[0], langAndCountry[1])));
            } else {
                FIELD_DESC_MAP.put(locale,
                        ResourceBundle.getBundle(FIELD_DESC, new Locale(locale)));
            }
        }
    }

    private static String getDescriptionByLocale(String key, String locale) {
        if (FIELD_DESC_MAP.containsKey(locale)) {
            return FIELD_DESC_MAP.get(locale).getString(key);
        } else {
            return key;
        }
    }

    static Map<String, String> getDescriptionByKey(String key) {
        HashMap<String, String> descMap = new HashMap<>();
        for (String locale : FIELD_DESC_MAP.keySet()) {
            descMap.put(locale, getDescriptionByLocale(key, locale));
        }
        return descMap;
    }
}

support_locales.properties

locales=zh_CN,en_US

fieldDesc.properties

xxx=xxx
yyy=yyy
zzz=zzz

fieldDesc_en_US.properties

xxx=x!x!x!
yyy=y!y!y!
zzz=z!z!z!

filedDesc_zh_CN.properties

xxx=未知X!
yyy=未知Y!
zzz=未知Z!

单元测试

FieldDescEnumTest.java

package enumsdemo;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializeConfig;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Helly Guo
 * <p>
 * Created on 3/1/20 1:59 PM
 */
public class FieldDescEnumTest {
    private static final Logger LOGGER = LoggerFactory.getLogger(FieldDescEnumTest.class);

    @Test
    public void test() {
        SerializeConfig config = new SerializeConfig();
        config.configEnumAsJavaBean(FieldDescEnum.class);
        LOGGER.info(JSON.toJSONString(FieldDescEnum.FIELD_X, config));
        LOGGER.info(JSON.toJSONString(FieldDescEnum.FIELD_Y, config));
        LOGGER.info(JSON.toJSONString(FieldDescEnum.FIELD_Z, config));
    }

}