java实现输出2个字符中相同的字符个数的输出

public class text{
	 public static void main(String[] args) {
		 	String a="abcdefg";
		 	String b="sxcvabcde";
		 	char[]aa=a.toCharArray();
		 	char[]bb=b.toCharArray();
			int [][]q=new int [a.length()+1][b.length()+1];
		 	int max=0;
		 	for (int i = 1; i< q.length; i++) {
				for (int j = 1; j<=bb.length; j++) {
						if(aa[i-1]==bb[j-1])
						q[i][j]=q[i-1][j-1]+1;
						if(q[i][j]>max)
						max=q[i][j];
				}
			}	
		 	System.out.println(max);
	 }
}