此工具类需要依赖谷歌的java开发工具包guava，这个工具包里面具备了很多功能具体的可以参考并发编程网关于guava的系列教程[ 快捷入口 ]：
 
CaseFomat提供的枚举常量的说明
 
SN
枚举常量
说明
1
LOWER_HYPHEN
连字符的变量命名规范如lower-hyphen
2
LOWER_UNDERSCORE
c++变量命名规范如lower_underscore
3
LOWER_CAMEL
java变量命名规范如lowerCamel
4
UPPER_CAMEL
java和c++类的命名规范如UpperCamel
5
UPPER_UNDERSCORE
java和c++常量的命名规范如UPPER_UNDERSCORE
 
maven依赖
 
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>21.0</version>
</dependency>
 
例子
 
import org.junit.Test;

import com.google.common.base.CaseFormat;

public class GuavaTester {

    @Test
    public void test() {
        System.out.println(CaseFormat.LOWER_HYPHEN.to(CaseFormat.LOWER_CAMEL, "test-data"));//testData
        System.out.println(CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, "test_data"));//testData
        System.out.println(CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, "test_data"));//TestData

        System.out.println(CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, "testdata"));//testdata
        System.out.println(CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, "TestData"));//test_data
        System.out.println(CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_HYPHEN, "testData"));//test-data

    }
}

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * <p>
 * ConvertUtil 转换工具类
 * </p>
 *
 * @author lut
 * @since 2019.5.02
 */
public class ConvertUtil {

    private static Pattern linePattern = Pattern.compile("_([a-z])");

    private static Pattern humpPattern = Pattern.compile("\\B(\\p{Upper})(\\p{Lower}*)");

    /**
     * 实体对象转成Map
     *
     * @param obj 实体对象
     * @return
     */
    public static Map<String, Object> object2Map(Object obj) {
        Map<String, Object> map = new HashMap<>();
        if (obj == null) {
            return map;
        }
        @SuppressWarnings("rawtypes")
        Class clazz = obj.getClass();
        Field[] fields = clazz.getDeclaredFields();
        try {
            for (Field field : fields) {
                field.setAccessible(true);
                map.put(field.getName(), field.get(obj));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return map;
    }

    /**
     * Map转成实体对象
     *
     * @param map   map实体对象包含属性
     * @param clazz 实体对象类型
     * @return
     */
    public static Object map2Object(Map<String, Object> map, Class<?> clazz) {
        if (map == null) {
            return null;
        }
        Object obj = null;
        try {
            obj = clazz.newInstance();

            Field[] fields = obj.getClass().getDeclaredFields();
            for (Field field : fields) {
                int mod = field.getModifiers();
                if (Modifier.isStatic(mod) || Modifier.isFinal(mod)) {
                    continue;
                }
                field.setAccessible(true);
                field.set(obj, map.get(field.getName()));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return obj;
    }


    /**
     * 下划线转驼峰
     *
     * @param str
     * @return
     */
    public static String lineToHump(String str) {
        Matcher matcher = linePattern.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, matcher.group(1).toUpperCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }


    /**
     * 驼峰转下划线(Map)
     *
     * @param str
     * @return
     */
    public static String humpToLine(String str) {
        Map<String, Object> map = JSONObject.parseObject(str);
        Map<String, Object> newMap = Maps.newHashMap();
        Iterator<Map.Entry<String, Object>> it = map.entrySet().iterator();
        while (it.hasNext()) {
            StringBuffer sb = new StringBuffer();
            Map.Entry<String, Object> entry = it.next();
            String key = entry.getKey();
            Matcher matcher = humpPattern.matcher(key);
            while (matcher.find()) {
                matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
            }
            matcher.appendTail(sb);
            newMap.put(sb.toString(), entry.getValue());
        }
        return JSON.toJSONString(newMap);

    }

    /**
     * 驼峰转下划线(List)
     *
     * @param str
     * @return
     */
    @SuppressWarnings("all")
    public static String humpToLineList(String str) {
        List<Map> list = JSONObject.parseArray(str, Map.class);
        List<Map<String, Object>> res = new ArrayList<>();
        list.stream().forEach(p -> {
            Map<String, Object> newMap = Maps.newHashMap();
            Iterator<Map.Entry<String, Object>> it = p.entrySet().iterator();
            while (it.hasNext()) {
                StringBuffer sb = new StringBuffer();
                Map.Entry<String, Object> entry = it.next();
                String key = entry.getKey();
                Matcher matcher = humpPattern.matcher(key);
                while (matcher.find()) {
                    matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
                }
                matcher.appendTail(sb);
                newMap.put(sb.toString(), entry.getValue());
            }
            res.add(newMap);
        });
        return JSON.toJSONString(res);
    }

 
packagecom.utils;public classChangeChar {public static final char UNDERLINE = '_';public static voidmain(String[] args) {/*驼峰转下划线*/String str= " itemName bbbbCsss , \n" +
 
" category ,\n" +
 
"\tbarCode\t \n" +
 
"\tvolume\t \n" +
 
"\tlength\t \n" +
 
"\twidth\t \n" +
 
"\theight\t \n" +
 
"\tunitPrice\t \n" +
 
"\tshelfLife\t \n" +
 
"\tshelfLifeUnit\t /\n" +
 
"\t )";/*下划线转驼峰*/String str2= " ITEM_NAME , \n" +
 
" CATEGORY ,\n" +
 
"\tBAR_CODE\t \n" +
 
"\tVOLUME\t \n" +
 
"\tLENGTH\t \n" +
 
"\tWIDTH\t \n" +
 
"\tHEIGHT\t \n" +
 
"\tUNIT_PRICE\t \n" +
 
"\tSHELF_LIFE\t \n" +
 
"\tSHELF_LIFE_UNIT\t";/*** 测试
 
**/
 
/*charType=2 表示大写, 其他情况都是小写*/String STR_ABC= camelToUnderline(str, 2); //下划线大写:ABC_DEF
 
String str_abc = camelToUnderline(str, 1); //下划线小写:abc_def
 
System.out.println("驼峰转化成下划线大写 :" +STR_ABC);
 
System.out.println("驼峰转化成下划线小写 :" +str_abc);
 
String strAbc= underlineToCamel(str2); //下划线转驼峰:abcDef
 
System.out.println("下划线化成驼峰 :" +strAbc);
 
}//驼峰转下划线
 
public staticString camelToUnderline(String param, Integer charType) {if (param == null || "".equals(param.trim())) {return "";
 
}int len =param.length();
 
StringBuilder sb= newStringBuilder(len);for (int i = 0; i < len; i++) {char c =param.charAt(i);if(Character.isUpperCase(c)) {
 
sb.append(UNDERLINE);
 
}if (charType == 2) {
 
sb.append(Character.toUpperCase(c));//统一都转大写
 
} else{
 
sb.append(Character.toLowerCase(c));//统一都转小写
 
}
 
}returnsb.toString();
 
}//下划线转驼峰
 
public staticString underlineToCamel(String param) {if (param == null || "".equals(param.trim())) {return "";
 
}int len =param.length();
 
StringBuilder sb= newStringBuilder(len);
 
Boolean flag= false; //"_" 后转大写标志,默认字符前面没有"_"
 
for (int i = 0; i < len; i++) {char c =param.charAt(i);if (c ==UNDERLINE) {
 
flag= true;continue; //标志设置为true,跳过
 
} else{if (flag == true) {//表示当前字符前面是"_" ,当前字符转大写
 
sb.append(Character.toUpperCase(param.charAt(i)));
 
flag= false; //重置标识
 
} else{
 
sb.append(Character.toLowerCase(param.charAt(i)));
 
}
 
}
 
}returnsb.toString();
 
}
 
}

java字符串下划线转驼峰工具使用
 
public class StringUtil {
	private static final char UNDERLINE='_'; 
    /**
     * 下划线 转 驼峰
     * @param param
     * @return
     */
    public static String underlineToCamel(String param){ 
        if (param==null||"".equals(param.trim())){  
            return "";  
        }  
        int len=param.length();  
        StringBuilder sb=new StringBuilder(len);  
        for (int i = 0; i < len; i++) {  
            char c = Character.toLowerCase(param.charAt(i));  
            if (c == UNDERLINE){  
               if (++i<len){  
                   sb.append(Character.toUpperCase(param.charAt(i)));  
               }  
            }else{  
                sb.append(c);  
            }  
        }  
        return sb.toString();  
    } 
}