java中进行二进制,八进制,十六进制,十进制间进行相互转换--688IT编程网

java中进行二进制，八进制，十六进制，十进制间进行相互转换

十进制转成十六进制：

十进制转成八进制

十进制转成二进制

十六进制转成十进制

Integer.valueOf("FFFF",16).toString()

八进制转成十进制

Integer.valueOf("876",8).toString()

二进制转十进制

Integer.valueOf("0101",2).toString()

有什么方法可以直接将2,8,16进制直接转换为10进制的吗?

java.lang.Integer类

parseInt(String s, int radix)

使用第二个参数指定的基数，将字符串参数解析为有符号的整数。

examples from jdk:

parseInt("0", 10) returns 0

parseInt("473", 10) returns 473

parseInt("-0", 10) returns 0

parseInt("-FF", 16) returns -255

parseInt("1100110", 2) returns 102

parseInt("2147483647", 10) returns 2147483647

parseInt("-2147483648", 10) returns -2147483648

parseInt("2147483648", 10) throws a NumberFormatException

parseInt("99", 8) throws a NumberFormatException

parseInt("Kona", 10) throws a NumberFormatException

parseInt("Kona", 27) returns 411787

进制转换如何写（二，八，十六）不用算法

例一：

public class Test{

public static void main(String args[]){

int i=100;

String BinaryString(i);

String OctalString(i);

String HexString(i);

System.out.println(binStr);

例二：

public class TestStringFormat {

public static void main(String[] args) {

if (args.length == 0) {

System.out.println("usage: java TestStringFormat <a number>");

}

Integer factor = Integer.valueOf(args[0]);

String s;

s = String.format("%d", factor);

System.out.println(s);

s = String.format("%x", factor);

System.out.println(s);

s = String.format("%o", factor);

System.out.println(s);

}

1.得到当前月的第一天和最后一天，注意3是4月份，从零开始

Calendar c = Instance();

c.set(Calendar.YEAR, 2007);

c.set(Calendar.MONTH, 3);

System.out.ActualMaximum(c.DAY_OF_MONTH));

System.out.ActualMinimum(c.DAY_OF_MONTH));

2.十六进制的转换

String st = "this is roger";

/ hex

for(int i = 0; i<st.length(); i++){

System.out.println();

int ch=(int)st.charAt( i );

String s4="00"+HexString( ch );

System.out.println(i + "output->"+s4); // String to Hex

//back String

int intVal = Integer.parseInt(s4, 16);

char charVal = (char) intVal;

System.out.println("The character is: "+charVal);

}

int temp = 1234567;

String hexString = HexString(temp);

System.out.println( "hexString = " + hexString );

String str = String(Integer.parseInt(hexString, 16));

System.out.println( "str =

" + str );

/ 转化十六进制编码为字符串

public static String toStringHex(String s)

{

byte[] baKeyword = new byte[s.length()/2];

for(int i = 0; i < baKeyword.length; i++)

{

try

{

baKeyword[i] = (byte)(0xff & Integer.parseInt(s.substring(i*2, i*2+2),16));

}

catch(Exception e)

{

e.printStackTrace();

}

try

{

s = new String(baKeyword, "utf-8");//UTF-16le:Not

}

catch (Exception e1)

{

e1.printStackTrace();

}

return s;

}

public static void main(String[] args) {

System.out.println(encode("中文"));

System.out.println(decode(encode("中文")));

}

* 16进制数字字符集

private static String hexString="0123456789ABCDEF";

* 将字符串编码成16进制数字，适用于所有字符（包括中文）

public static String encode(String str)

{

/根据默认编码获取字节数组

byte[] Bytes();

StringBuilder sb=new StringBuilder(bytes.length*2);

//将字节数组中每个字节拆解成2位16进制整数

for(int i=0;i<bytes.length;i++)

{

sb.append(hexString.charAt((bytes[i]&0xf0)>>4));

sb.append(hexString.charAt((bytes[i]&0x0f)>>0));

}

String();

}

* 将16进制数字解码成字符串，适用于所有字符（包括中文）

public static String decode(String bytes)

{

ByteArrayOutputStream baos=new ByteArrayOutputStream(bytes.length()/2);

//将每2位16进制整数组装成一个字节

for(int i=0;i<bytes.length();i+=2)

baos.write((hexString.indexOf(bytes.charAt(i))<<4 |hexString.indexOf(bytes.charAt(i+1))));

return new ByteArray());

}

或

String str="中";

char c=(char)str.charAt(0);

System.out.println(c+"转换为16进制为："+String(c,16));

System.out.println("16进制转换为字符串为:"+(char)Integer.String(c, 16),16).intValue());

public class testcolor {

private static byte uniteBytes(byte src0, byte src1) {

byte _b0 = Byte.decode("0x" + new String(new byte[] {src0})).byteValue();

_b0 = (byte) (_b0 << 4);

byte _b1 = Byte.decode("0x" + new String(new byte[] {src1})).byteValue();

byte ret = (byte) (_b0 ^ _b1);

// System.out.println(ret<<8);

return ret;

}

/**

* @param src

* @return

/*private static byte[] HexString2Bytes(String src) {

byte[] ret = new byte[6];

byte[] tmp = Bytes();

for (int i = 0; i < 3; i++) {

ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);

}

return ret;

}

;*/

public static byte[] HexString2Bytes(String src)

{ byte[] ret = new byte[6];

byte[] tmp = Bytes(); for(int i=0; i<6; ++i ){ ret[i] = uniteBytes(tmp[i*2], tmp[i*2+1]); } return ret; }

/**

* @param args

public static void main(String[] args) {

// TODO 自动生成方法存根

String s="ff22ee";

Number ss;

byte[] ret = new byte[6];

Integer i=new Integer(ret[0]);

ret = HexString2Bytes(s) ;

int c=((ret[2]<<8|ret[1]<<8|ret[0])|0xff000000);

//Color cc=new Color(c);

// System.out.Red()+":::"+cc.getBlue()+":::"+cc.getGreen());

}

将IP地址转为10进制数，使用小端模式

public static int parseIPNUmber(String ipNumberStr)

throws IllegalArgumentException {

int result = 0;

if (ipNumberStr == null) {

throw new IllegalArgumentException();

}

StringTokenizer tokenizer = new StringTokenizer(ipNumberStr, ".");

try {

String tmp = ipNumberStr;

/ get the 3 first numbers

int offset = 0;

for (int i = 0; i < 3; i++) {

// get the position of the first dot

int index = tmp.indexOf(".");

// if there is not a dot then the ip string representation is

// not compliant to the decimal-dotted notation.

if (index != -1) {

16进制字符串转16进制数组// get the number before the dot and convert it into

// an integer.

String numberStr = tmp.substring(0, index);

int number = Integer.parseInt(numberStr);

if ((number < 0) || (number > 255)) {