Java common tips

1: How to print a two-dimensional array?

int[][]array = new int[][]{{a,b,c},{d,b,d}，{q,e,f}，{d,h,e}};
System.out.println(Arrays.deepToString(array));

2: How to convert between String, StringBuilder?

StringBuilder sb = new StringBuilder("sb");
String s = new String("gg");
String s1 = new String(""+sb);
StringBuilder sb = new StringBuilder(s);

3: How to int, mutual conversion between byte?