java将一个整数转化成二进制代码示例

   @Test 
public void test1(){ 
  BigInteger b=new BigInteger("10");//1010 
  System.out.println(b.toString(2));//0 
   
  b=new BigInteger("1"); 
  System.out.println(b.toString(2));//1 
   
  b=new BigInteger("255"); 
  System.out.println(b.toString(2));//11111111 
   
  b=new BigInteger("254"); 
  System.out.println(b.toString(2));//11111110 
} 

   @Test 
public void test(){ 
  String str2 = Integer.toBinaryString(0); 
  System.out.println(str2);//0 
   
  str2 = Integer.toBinaryString(1); 
  System.out.println(str2);//1 
   
  str2 = Integer.toBinaryString(255); 
  System.out.println(str2);//11111111 
} 

@Test 
public void test3(){ 
   
  String tempStr = ""; 
  String str2 = Integer.toBinaryString(10); 
    //判断一下：如果转化为二进制为0或者1或者不满8位，要在数后补0 
    int bit = 8-str2.length(); 
    if(str2.length()<8){ 
      for(int j=0; j<bit; j++){ 
      str2 = "0"+str2; 
      } 
    } 
    tempStr += str2; 
    System.out.println(tempStr); 
}