Java 基础 byte[]与各种数据类型互相转换的简单示例
Java基础byte[]与各种数据类型互相转换的简单示例
这里对byte[]类型对long,int,double,float，short,cahr，object,string类型相互转换的实例，
在socket开发过程中，通常需要将一些具体的值（这些值可能是各种Java类型）转化为byte[]类型，为此我总结了如下这个示例，贴出来，以便经常翻看：
publicclassTestCase{
/**
*short到字节数组的转换.
*/
publicstaticbyte[]shortToByte(shortnumber){
inttemp=number;
byte[]b=newbyte[2];
for(inti=0;i<b.length;i++){
b[i]=newInteger(temp&0xff).byteValue();//将最低位保存在最低位
temp=temp>>8;//向右移8位
}
returnb;
}
/**
*字节数组到short的转换.
*/
publicstaticshortbyteToShort(byte[]b){
shorts=0;
shorts0=(short)(b[0]&0xff);//最低位
shorts1=(short)(b[1]&0xff);
s1<<=8;
s=(short)(s0|s1);
returns;
}
/**
*int到字节数组的转换.
*/
publicstaticbyte[]intToByte(intnumber){
inttemp=number;
byte[]b=newbyte[4];
for(inti=0;i<b.length;i++){
b[i]=newInteger(temp&0xff).byteValue();//将最低位保存在最低位
temp=temp>>8;//向右移8位
}
returnb;
}
/**
*字节数组到int的转换.
*/
publicstaticintbyteToInt(byte[]b){
ints=0;
ints0=b[0]&0xff;//最低位
ints1=b[1]&0xff;
ints2=b[2]&0xff;
ints3=b[3]&0xff;
s3<<=24;
s2<<=16;
s1<<=8;
s=s0|s1|s2|s3;
returns;
}
/**
*long类型转成byte数组
*/
publicstaticbyte[]longToByte(longnumber){
longtemp=number;
byte[]b=newbyte[8];
for(inti=0;i<b.length;i++){
b[i]=newLong(temp&0xff).byteValue();//将最低位保存在最低位temp=temp
//>>8;//向右移8位
}
returnb;
}
/**
*字节数组到long的转换.
*/
publicstaticlongbyteToLong(byte[]b){
longs=0;
longs0=b[0]&0xff;//最低位
longs1=b[1]&0xff;
longs2=b[2]&0xff;
longs3=b[3]&0xff;
longs4=b[4]&0xff;//最低位
longs5=b[5]&0xff;
longs6=b[6]&0xff;
longs7=b[7]&0xff;
//s0不变
s1<<=8;
s2<<=16;
s3<<=24;
s4<<=8*4;
s5<<=8*5;
s6<<=8*6;
s7<<=8*7;
s=s0|s1|s2|s3|s4|s5|s6|s7;
returns;
}
/**
*double到字节数组的转换.
*/
publicstaticbyte[]doubleToByte(doublenum){
byte[]b=newbyte[8];
longl=Double.doubleToLongBits(num);
for(inti=0;i<8;i++){
b[i]=newLong(l).byteValue();
l=l>>8;
}
returnb;
}
/**
*字节数组到double的转换.
*/
publicstaticdoublegetDouble(byte[]b){
longm;
m=b[0];
m&=0xff;
m|=((long)b[1]<<8);
m&=0xffff;
m|=((long)b[2]<<16);
m&=0xffffff;
m|=((long)b[3]<<24);
m&=0xffffffffl;
m|=((long)b[4]<<32);
m&=0xffffffffffl;
m|=((long)b[5]<<40);
m&=0xffffffffffffl;
m|=((long)b[6]<<48);
m&=0xffffffffffffffl;
m|=((long)b[7]<<56);
returnDouble.longBitsToDouble(m);
}
/**
*float到字节数组的转换.
*/
publicstaticvoidfloatToByte(floatx){
//先用Float.floatToIntBits(f)转换成int
}
/**
*字节数组到float的转换.
*/
publicstaticfloatgetFloat(byte[]b){
//4bytes
intaccum=0;
for(intshiftBy=0;shiftBy<4;shiftBy++){
accum|=(b[shiftBy]&0xff)<<shiftBy*8;
}
returnFloat.intBitsToFloat(accum);
}
/**
*char到字节数组的转换.
*/
publicstaticbyte[]charToByte(charc){
byte[]b=newbyte[2];
b[0]=(byte)((c&0xFF00)>>8);
b[1]=(byte)(c&0xFF);
returnb;
}
/**
*字节数组到char的转换.
*/
publicstaticcharbyteToChar(byte[]b){
charc=(char)(((b[0]&0xFF)<<8)|(b[1]&0xFF));
returnc;
}
/**
*string到字节数组的转换.
*/
publicstaticbyte[]stringToByte(Stringstr)throwsUnsupportedEncodingException{
returnstr.getBytes("GBK");
}
/**
*字节数组到String的转换.
*/
publicstaticStringbytesToString(byte[]str){
Stringkeyword=null;
try{
keyword=newString(str,"GBK");
}catch(UnsupportedEncodingExceptione){
e.printStackTrace();
}
returnkeyword;
}
/**
*object到字节数组的转换
*/
@Test
publicvoidtestObject2ByteArray()throwsIOException,
ClassNotFoundException{
//Objectobj="";
Integer[]obj={1,3,4};
////objecttobytearray
ByteArrayOutputStreambo=newByteArrayOutputStream();
ObjectOutputStreamoo=newObjectOutputStream(bo);
oo.writeObject(obj);
byte[]bytes=bo.toByteArray();
bo.close();
oo.close();
System.out.println(Arrays.toString(bytes));
Integer[]intArr=(Integer[])testByteArray2Object(bytes);
System.out.println(Arrays.asList(intArr));
byte[]b2=intToByte(123);
System.out.println(Arrays.toString(b2));
inta=byteToInt(b2);
System.out.println(a);
}
/**
*字节数组到object的转换.
*/
privateObjecttestByteArray2Object(byte[]bytes)throwsIOException,
ClassNotFoundException{
//byte[]bytes=null;
Objectobj;
//bytearraytoobject
ByteArrayInputStreambi=newByteArrayInputStream(bytes);
ObjectInputStreamoi=newObjectInputStream(bi);
obj=oi.readObject();
bi.close();
oi.close();
System.out.println(obj);
returnobj;
}
}
感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！