自己做的小练习，希望能帮到大家。

public class OverlapStr {

public static void main(String[] args){

Scanner scanner = new Scanner(System.in);

String str = scanner.nextLine();

char[] strArray = str.toCharArray();

StringBuffer result = new StringBuffer(str);

int index1 = 0;

int index2 = 0;

for(int startIndex = 1; startIndex< strArray.length; startIndex++){

index1 = startIndex;

index2 = 0;

while(strArray[index1] == strArray[index2]){

index1++;

index2++;

if (index1 == strArray.length){

while(index2 < strArray.length){

result.append(strArray[index2]);

index2++;

}

break;

}

}

if (result.length() > strArray.length){

break;

}

if ((index1 == strArray.length-1 ) && (index2 == 0)){

result.append(str);

break;

}

}

System.out.println(result);

}

}