数字类型转换成字符串型：
String s = String.valueOf(value); 

数字对象转换成字符串型
Long l = new Long(10);
String s = l.toString();

数字类型/字符串转换成数字对象：
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 );

数字对象转换成数字类型：(*o为一数字对象)
b = bo.byteValue();
t = to.shortValue();
i = io.intValue();
l = lo.longValue();
f = fo.floatValue();
d = dObj.doubleValue();