Java 字符串转换

包含了：

• 首字母转大写
• 下划线转驼峰

• 驼峰转下划线 ```java /**

  • @author xq
  • @date 2022/03/24 15:00

  • @describe 字符工具类 */ public class StrUtil { private static Pattern linePattern = Pattern.compile(“_(\w)”);

    /**

    • 首字母转大写 *
    • @param name

    • @return */ public static String captureName(String name) { // name = name.substring(0, 1).toUpperCase() + name.substring(1); // return name;

      char[] cs = name.toCharArray(); if (cs[0] >= 97 && cs[0] <= 122) {

       cs[0] -= 32;

      } return String.valueOf(cs); }

    /**

    • 下划线转驼峰 */ public static String lineToHump(String str) { str = str.toLowerCase(); 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(); }

/**
 * 下划线转驼峰
 */
public static String lineToHumpNoChangeCase(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(简单写法，效率低于{@link #humpToLine2(String)})
 */
public static String humpToLine(String str) {
    return str.replaceAll("[A-Z]", "_$0").toLowerCase();
}
private static Pattern humpPattern = Pattern.compile("[A-Z]");
/**
 * 驼峰转下划线,效率比上面高
 */
public static String humpToLine2(String str) {
    Matcher matcher = humpPattern.matcher(str);
    StringBuffer sb = new StringBuffer();
    while (matcher.find()) {
        matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
    }
    matcher.appendTail(sb);
    return sb.toString();
}
public static String captureAndLineToHump(String field) {
    return lineToHumpNoChangeCase(captureName(field));
}

} ```