package studyjava; public class MyStringBuffer implements IStringBuffer{ String s; @Override public void append(String str) { System.out.println("此方法可在末尾追加字符串"); s += str;//s可根据需要提前声明。或利用Scanner输入。 System.out.println(s); } @Override public void append(char c) { System.out.println("此方法可在末尾追加字符"); s += c;//s可根据需要提前声明。或利用Scanner输入。 System.out.println(s); } @Override public void insert(int pos, char b) { //虽然StringBuffer的总空间大于内容长度，但最多可以在位置是“原数据的长度（这里为12）”插入新元素，即紧接着原数据。 //经测试，上述规则和StringBuffer的插入规则一样 String s = "I can do it!";//测试用。假设它为原字符串。 String s2 = ""; String s3= ""; char[] C = s.toCharArray(); for (int i = 0; i < pos; i++) { s2 += C[i]; } for (int j = pos ; j < C.length; j++) { s3 += C[j]; } System.out.println("在指定位置插入字符串后的新字符为: " + s2 + b + s3); } @Override public void insert(int pos, String b) { String s2 = "abcde";//测试用。假设它为原字符串 String s3 = ""; String s4 = ""; String[] S = s2.split(""); for (int i = 0; i < pos; i++) { s3 += S[i]; } for (int j = pos ; j < S.length ; j++) { s4 += S[j]; } System.out.println("在指定位置插入字符串后的新字符为: " + s3 + b + s4); } @Override public void delete(int start) { String s = "DAnte";//测试用。假设它为原字符串 String s2 = ""; String[] S = s.split(""); for (int i = 0; i < start; i++) { s2 += S[i]; } System.out.println(s2); } @Override public void delete(int start, int end) { String s = "Let us go!";//测试用。假设它为原字符串 String s2 = ""; String[] S = s.split(""); for (int i = start; i < end; i++) { S[i] = null; } for (int i = 0; i < S.length; i++) { if(S[i] != null) { s2 += S[i]; } } System.out.println(s2); } @Override public void reverse() { String s = "Devil";//测试用。假设它为原字符串 String s2 = ""; String[] S = s.split(""); String[] S2 = s.split(""); int b = S.length - 1; for (int i = 0; i < S.length / 2; i++) { S[i] = S[b]; s2 += S[i]; b--; } for (int i = S2.length / 2 ; i < S2.length; i++) { S[i] = S2[b]; s2 += S[i]; b--; } System.out.println(s2); } @Override public int length() { String s = "Rainbow";//测试用。假设它为原字符串 int Chang = 0; for (int i = 0; i < s.length(); i++) { Chang++; } return Chang; } }