java实现身份证15位转18位

public static final String getNewId(String id)
{

final int [] W =
{
7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, 1};
final String [] A =
{
"1", "0", "X", "9", "8", "7", "6", "5", "4", "3", "2"};
int i,j,s=0;
String newid;
newid = id;
newid =newid.substring(0,6)+"19"+newid.substring(6,id.length());
for ( i=0;i<newid.length() ;i++ )
{

j= Integer.parseInt(newid.substring(i,i+1))*W[i];
s=s+j;
}
s = s % 11;
newid=newid+A[s];

return newid;

}