Java join string connection usage

1. You can use "+" to connect characters. 2. you can use the append method of stringBuffer to directly add characters to the end. you can use the above two methods to write the Join method that meets your requirements. import java. util. hashMap; import java. util. regex. pattern; public class StringHelper {public static String join (String [] array) {return join (array, "");} public static String join (String [] array, String delimiter) {int delimiterLength = delimiter. length (); if (array. length = 0) return ""; if (array. length = 1) {if (array [0] = null) return ""; return array [0];} // of the resulting string. int length = 0; for (int I = 0; INull. * @ Return Joined string. */public static String join (final StringBuffer buff, final Object array [], final String delim) {boolean haveDelim = (delim! = Null); for (int I = 0; I <array. length; I ++) {buff. append (array [I]); // if this is the last element then don't append delim if (haveDelim & (I + 1) <array. length) {buff. append (delim) ;}} return buff. toString ();}/*** Join an array of strings into one delimited string. ** @ param array Array of objects to join as strings. * @ param delim Delimiter to join strings with or Null. * @ Return Joined string. */public static String join (final Object array [], final String delim) {return join (new StringBuffer (), array, delim );} /*** Convert and join an array of objects into one string. ** @ param array Array of objects to join as strings. * @ return Converted and joined objects. */public static String join (final Object array []) {return join (array, null);}/*** Convert and join an array of bytes into one string. ** @ param array Array of objects to join as strings. * @ return Converted and joined objects. */public static String join (final byte array []) {Byte bytes [] = new Byte [array. length]; for (int I = 0; I <bytes. length; I ++) {bytes [I] = new Byte (array [I]);} return join (bytes, null );} /*** Return a string composed of the given array. ** @ param buff Buffer used to construct string value (not reset ). * @ param array Array of objects. * @ param prefix String prefix. * @ param separator Element sepearator. * @ param suffix String suffix. * @ return String in the format of: * prefix + n (+ separator + n + I) * + suffix. */public static String join (final StringBuffer buff, final Object [] array, final String prefix, final String separator, final String suffix) {buff. append (prefix); join (buff, array, separator); buff. append (suffix); return buff. toString ();}/*** Return a string composed of the given array. ** @ param array Array of objects. * @ param prefix String prefix. * @ param separator Element sepearator. * @ param suffix String suffix. * @ return String in the format of: * prefix + n (+ separator + n + I) * + suffix. */public static String join (final Object [] array, final String prefix, final String separator, final String suffix) {return join (new StringBuffer (), array, prefix, separator, suffix );}}