package Demo8;
import java.net.InetAddress;
/**
* 查看一个已知地址是否为垃圾邮件发送者
*
*/
public class SpamCheck {
public static final String BLACKHOLE = "sbl.spamhaus.org";
public static void main(String[] args) {
if(isSpamer("www.baidu.com")){
System.out.println("是垃圾发送者");
}else{
System.out.println("不是垃圾发送者");
}
}
private static boolean isSpamer(String string) {
try {
InetAddress inet = InetAddress.getByName(string);
byte [] quad = inet.getAddress();
String query = BLACKHOLE;
for(byte octet : quad){
int unsignedByte = octet <0 ? octet + 256 : octet;
query = unsignedByte + "." + query;
}
//27.210.239.115.sbl.spamhaus.org 倒置ip添加sbl.spamhaus.org查询dns
System.out.println(query);
InetAddress.getByName(query);
return true;
} catch (Exception e) {
return false;
}
}
}
这是java网络编程上的一个验证某个地址是否为垃圾邮件发送者的demo,我有几个问题:
1.这段代码有用吗?我已百度为测试的话发现其为垃圾发送真
2.27.210.239.115.sbl.spamhaus.org这段域名在DNS上一定存在,为什么存在就是垃圾发送者?
谢谢大神帮我解答