Java--变量名驼峰式和下划线互转

最近写代码的时候，涉及到解析报文这一块的知识，解析报文中的数据得到Java数据时，得到的变量名竟然是是下划线的，正常我们Java当中用的是驼峰式命名规则，因此需要驼峰式、下划线变量名之间进行转换。代码主要包含以下几种转换：

下划线转驼峰式（String）
驼峰式转下划线（String）
下划线转驼峰式（Map）
驼峰式转下划线（Map）

实现代码

  

   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import java.util.HashMap;
     
    
   

    

     

    
    

     

      import java.util.Iterator;
     
    
   

    

     

    
    

     

      import java.util.Map;
     
    
   

    

     

    
    

     

      import java.util.Map.Entry;
     
    
   

    

     

    
    

     

      import java.util.regex.Matcher;
     
    
   

    

     

    
    

     

      import java.util.regex.Pattern;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      /**
     
    
   

    

     

    
    

     

       * Java String、Map String key的驼峰式和下划线互转
     
    
   

    

     

    
    

     

       * @author JustinQin
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     

      public class CamelToUnderlineConvertUtil {
     
    
   

    

     

    
    

     
	
     
    
   

    

     

    
    

     
	/**
     
    
   

    

     

    
    

     

       * 下划线转驼峰式（String）
     
    
   

    

     

    
    

     

       * @param lineString
     
    
   

    

     

    
    

     

       * @param smallCamel true-返回小驼峰,false-大驼峰式
     
    
   

    

     

    
    

     

       * @return
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
	public static String underlineToCamel(String lineString,boolean smallCamel){
     
    
   

    

     

    
    

     
		if(null == lineString || "".equals(lineString)) return lineString;
     
    
   

    

     

    
    

     

      		StringBuffer sb = new StringBuffer();
     
    
   

    

     

    
    

     

      		Pattern pattern = Pattern.compile("([A-Za-z\\d]+)(_)?");	//字母、数字、下划线
     
    
   

    

     

    
    

     

      		Matcher matcher = pattern.matcher(lineString);
     
    
   

    

     

    
    

     
		while (matcher.find()) {
     
    
   

    

     

    
    

     
			String word = matcher.group();
     
    
   

    

     

    
    

     

      			sb.append(smallCamel && matcher.start() == 0 ?
     
    
   

    

     

    
    

     

      					Character.toLowerCase(word.charAt(0)) : Character.toUpperCase(word.charAt(0)));
     
    
   

    

     

    
    

     
			int index = word.lastIndexOf("_");
     
    
   

    

     

    
    

     
			if(index > 0){
     
    
   

    

     

    
    

     

      				sb.append(word.substring(1, index).toLowerCase());
     
    
   

    

     

    
    

     

      			}else{
     
    
   

    

     

    
    

     

      				sb.append(word.substring(1).toLowerCase());
     
    
   

    

     

    
    

     

      			}
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		return sb.toString();
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	/**
     
    
   

    

     

    
    

     

       * 驼峰式转下划线（String）
     
    
   

    

     

    
    

     

       * @param camelString
     
    
   

    

     

    
    

     

       * @return
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
	public static String camelToUnderline(String camelString){
     
    
   

    

     

    
    

     
		if(null == camelString || "".equals(camelString)) return camelString;
     
    
   

    

     

    
    

     

      		camelString = String.valueOf(camelString.charAt(0)).toUpperCase().concat(camelString.substring(1));
     
    
   

    

     

    
    

     
		
     
    
   

    

     

    
    

     

      		StringBuffer sb = new StringBuffer();
     
    
   

    

     

    
    

     

      		Pattern pattern = Pattern.compile("[A-Z]([a-z\\d]+)?");	//字母、数字、下划线
     
    
   

    

     

    
    

     

      		Matcher matcher = pattern.matcher(camelString);
     
    
   

    

     

    
    

     
		while (matcher.find()) {
     
    
   

    

     

    
    

     
			String word = matcher.group();
     
    
   

    

     

    
    

     

      			sb.append(word.toLowerCase());
     
    
   

    

     

    
    

     

      			sb.append(matcher.end() == camelString.length() ? "" : "_");
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		return sb.toString();
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	
     
    
   

    

     

    
    

     
	
     
    
   

    

     

    
    

     
	/**
     
    
   

    

     

    
    

     

       * 下划线转驼峰式（Map）
     
    
   

    

     

    
    

     

       * @param map
     
    
   

    

     

    
    

     

       * @return newMap
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
	public static Map<String,Object> underlineToCamel(Map<String,Object> map){
     
    
   

    

     

    
    

     

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

    

     

    
    

     
		Iterator<Entry<String, Object>> iterator = map.entrySet().iterator();
     
    
   

    

     

    
    

     

      		Entry<String, Object> entry;
     
    
   

    

     

    
    

     
		while(iterator.hasNext()){
     
    
   

    

     

    
    

     

      			entry  = iterator.next();
     
    
   

    

     

    
    

     
			if(null != entry.getKey() && entry.getKey() instanceof String){
     
    
   

    

     

    
    

     

      				newMap.put(underlineToCamel(entry.getKey(), true), entry.getValue());
     
    
   

    

     

    
    

     

      			}
     
    
   

    

     

    
    

     
			iterator.remove();
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		return newMap;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	/**
     
    
   

    

     

    
    

     

       * 驼峰式转下划线（Map）
     
    
   

    

     

    
    

     

       * @param map
     
    
   

    

     

    
    

     

       * @return newMap
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
	public static Map<String,Object> camelToUnderline(Map<String,Object> map){
     
    
   

    

     

    
    

     

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

    

     

    
    

     
		Iterator<Entry<String, Object>> iterator = map.entrySet().iterator();
     
    
   

    

     

    
    

     

      		Entry<String, Object> entry;
     
    
   

    

     

    
    

     
		while(iterator.hasNext()){
     
    
   

    

     

    
    

     

      			entry  = iterator.next();
     
    
   

    

     

    
    

     
			if(null != entry.getKey() && entry.getKey() instanceof String){
     
    
   

    

     

    
    

     

      				newMap.put(camelToUnderline(entry.getKey()), entry.getValue());
     
    
   

    

     

    
    

     

      			}
     
    
   

    

     

    
    

     
			iterator.remove();
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		return newMap;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	
     
    
   

    

     

    
    

     
	public static void main(String[] args) {
     
    
   

    

     

    
    

     

      		System.out.println(underlineToCamel("Justin_qin_jj", false));
     
    
   

    

     

    
    

     

      		System.out.println(camelToUnderline("JustinQinJj"));
     
    
   

    

     

    
    

     
		
     
    
   

    

     

    
    

     

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

    

     

    
    

     

      		map.put("yourName", "Justin");
     
    
   

    

     

    
    

     

      		map.put("yourSex", "男");
     
    
   

    

     

    
    

     

      		map.put("youreAge", 22);
     
    
   

    

     

    
    

     
		
     
    
   

    

     

    
    

     

      		Map<String, Object> camelToUnderlineMap = camelToUnderline(map);
     
    
   

    

     

    
    

     

      		System.out.println(camelToUnderlineMap.toString());
     
    
   

    

     

    
    

     
		
     
    
   

    

     

    
    

     

      		Map<String, Object> underlineToCamelMap = underlineToCamel(camelToUnderlineMap);
     
    
   

    

     

    
    

     

      		System.out.println(underlineToCamelMap.toString());
     
    
   

    

     

    
    

     
		
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: blog.csdn.net，作者：吾日三省贾斯汀，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/JustinQin/article/details/102542086