java properties工具类整理

保持顺序的 Java Properties 类

import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Properties;
import java.util.Set;
 
/**
 * OrderedProperties
 */
public class OrderedProperties extends Properties {
 
    private static final long serialVersionUID = -4627607243846121965L;
     
    private final LinkedHashSet<Object> keys = new LinkedHashSet<Object>();
 
    public Enumeration<Object> keys() {
        return Collections.<Object> enumeration(keys);
    }
 
    public Object put(Object key, Object value) {
        keys.add(key);
        return super.put(key, value);
    }
 
    public Set<Object> keySet() {
        return keys;
    }
 
    public Set<String> stringPropertyNames() {
        Set<String> set = new LinkedHashSet<String>();
 
        for (Object key : this.keys) {
            set.add((String) key);
        }
 
        return set;
    }
}

根据封装好的OrderedProperties类封装

/**
 * 
 * @author xxh
 *
 */
final public class PropertiesFile {
	
	private static Map<String,Map<String,String>> files = new HashMap<String,Map<String,String>>();
	private PropertiesFile(){}
	
	/**
	 *  根据properties文件名把对应的属性值装换成map, 获取属性值直接从map中去对应的key
	 * @param file
	 * @return
	 * @throws ExcelException
	 */
	public static Map<String,String> properties2Map(String file) throws ExcelException{
		Map<String,String> map = files.get(file);
		if(map != null)//缓存中的map
			return map;
		map = new LinkedHashMap<String,String>();
		System.err.println("读取配置文件-------------------"+file);
		Properties props = null;
		try {
			props = new OrderedProperties();
			props.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("properties_config/"+file));
		} catch (IOException e) {
			throw new RuntimeException("类路径properties_config下需要放置["+file+"]文件！", e);
		}catch(NullPointerException e){
			throw new RuntimeException("类路径properties_config下需要放置["+file+"]文件！", e);
		}
		for(Object key : props.keySet()){
			map.put((String)key, (String)props.get(key));
		}
		props.clear();
		files.put(file, map);
		return map;
	}
}