用java 给数组从小到大排序

public static void mian(String [] args) {
int start = 0,end ,middle;
int a[] = {12,45,67,89,123,-45,67};
int N = ;
for(int i = 0;i<N;i++) {
for(int j = i+1;j<N;j++) {
if (a[j]>a[i]) {
int t = a[j];
a[j] = a[i];
a[i] = t;
}
}
}