org.fisco.bcos.web3j.utils.Strings Maven / Gradle / Ivy

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package org.fisco.bcos.web3j.utils;

import java.util.List;

/** String utility functions. */
public class Strings {

  private Strings() {}

  public static String toCsv(List src) {
    // return src == null ? null : String.join(", ", src.toArray(new String[0]));
    return join(src, ", ");
  }

  public static String join(List src, String delimiter) {
    return src == null ? null : String.join(delimiter, src.toArray(new String[0]));
  }

  public static String capitaliseFirstLetter(String string) {
    if (string == null || string.length() == 0) {
      return string;
    } else {
      return string.substring(0, 1).toUpperCase() + string.substring(1);
    }
  }

  public static String lowercaseFirstLetter(String string) {
    if (string == null || string.length() == 0) {
      return string;
    } else {
      return string.substring(0, 1).toLowerCase() + string.substring(1);
    }
  }

  public static String zeros(int n) {
    return repeat('0', n);
  }

  public static String repeat(char value, int n) {
    return new String(new char[n]).replace("\0", String.valueOf(value));
  }

  public static boolean isEmpty(String s) {
    return s == null || s.length() == 0;
  }
}