Java中实现字符串与十六进制编码相互转换

//转化字符串为十六进制编码
public static String toHexString(String s)   
{   
	String str="";   
	
	for (int i=0;i<s.length();i++)   
   	{   
		int ch = (int)s.charAt(i);   
		String s4 = Integer.toHexString(ch);   
		str = str + s4; 
   	}   
   	return "0x" + str;//0x表示十六进制
}

//转换十六进制编码为字符串
public static String toStringHex(String s)
{
	if("0x".equals(s.substring(0, 2)))
	{
		s =s.substring(2);
	}
	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;
}

//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
//下面做个测试
public static void main(String[] args) throws Exception
{
	String str = "test";
	printHexString(str.getBytes());
}

public static void printHexString( byte[] b) { 
	for (int i = 0; i < b.length; i++) { 
   	String hex = Integer.toHexString(b[i] & 0xFF); 
   	if (hex.length() == 1) { 
   		hex = '0' + hex; 
   	} 
   	System.out.print(hex.toUpperCase() ); 
   	} 
}


//输出结果:74657374