各种数字类型转换成字符串型： 

String s = String.valueOf( value); // 其中 value 为任意一种数字类型。 

字符串型转换成各种数字类型： 

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 ); 

数字类型与数字类对象之间的转换： 

byte b = 169; 
Byte bo = new Byte( b ); 
b = bo.byteValue(); 

short t = 169; 
Short to = new Short( t ); 
t = to.shortValue(); 

int i = 169; 
b = bo.byteValue(); 

short t = 169; 
Short to = new Short( t ); 
t = to.shortValue(); 

int i = 169; 
Integer io = new Integer( i ); 
i = io.intValue(); 

long l = 169; 
Long lo = new Long( l ); 
l = lo.longValue(); 

float f = 169f; 
Float fo = new Float( f ); 
f = fo.floatValue(); 

double d = 169f; 
Double dObj = new Double( d ); 
d = dObj.doubleValue();