數字類型轉換成字符串型：
String s = String.valueOf(value);?

數字對象轉換成字符串型
Long l = new Long(10);
String s = l.toString();

數字類型/字符串轉換成數字對象：
byte b = 169;
String b = "169";
Byte bo = new Byte( b );

short t = 169;
String b = "169";
Short to = new Short( t );

int i = 169;
String b = "169";
Integer io = new Integer( i );

long l = 169;
String b = "169";
Long lo = new Long( l );

float f = 169f;
String b = "169";
Float fo = new Float( f );

double d = 169f;
String b = "169";
Double dObj = new Double( d );?

字符串型轉換成各種數字類型：
String s = "169";
byte b = Byte.parseByte( s );
short t = Short.parseShort( s );
int i = Integer.parseInt( s );
long l = Long.parseLong( s );
float f = Float.parseFloat( s );
double d = Double.parseDouble( s );

數字對象轉換成數字類型：(*o為一數字對象)
b = bo.byteValue();
t = to.shortValue();
i = io.intValue();
l = lo.longValue();
f = fo.floatValue();
d = dObj.doubleValue();