新增 IP 地址工具

helper/src/main/java/com/github/mrzhqiang/helper/uppc/IPAddressTool.java

@@ -0,0 +1,57 @@
+package com.github.mrzhqiang.helper.uppc;
+
+/**
+ * Provides a class with tools for working with IP addresses, in both strings
+ * and as long integers.
+ *
+ * @author Nol888
+ * @version 0.1
+ * @since Revision 890
+ */
+public class IPAddressTool {
+
+    /**
+     * Converts a dotted-quad IP (<code>127.0.0.1</code>) and turns it into a
+     * long integer IP.
+     *
+     * @param dottedQuad The IP address in dotted-quad form.
+     * @return The IP as a long integer.
+     * @throws RuntimeException
+     */
+    public static final long dottedQuadToLong(final String dottedQuad) throws RuntimeException {
+        final String[] quads = dottedQuad.split("\\.");
+        if (quads.length != 4) {
+            throw new RuntimeException("Invalid IP Address format.");
+        }
+        long ipAddress = 0;
+        for (int i = 0; i < 4; i++) {
+            ipAddress += (long) (Integer.parseInt(quads[i]) % 256) * (long) Math.pow(256, (double) (4 - i));
+        }
+        return ipAddress;
+    }
+
+    /**
+     * Converts a long integer IP into a dotted-quad IP.
+     *
+     * @param longIP The IP as a long integer.
+     * @return The IP as a dotted-quad string.
+     * @throws RuntimeException
+     */
+    public static final String longToDottedQuad(long longIP) throws RuntimeException {
+        StringBuilder ipAddress = new StringBuilder();
+
+        for (int i = 0; i < 4; i++) {
+            int quad = (int) (longIP / (long) Math.pow(256, (double) (4 - i)));
+            longIP -= (long) quad * (long) Math.pow(256, (double) (4 - i));
+            if (i > 0) {
+                ipAddress.append(".");
+            }
+            if (quad > 255) {
+                throw new RuntimeException("Invalid long IP address.");
+            }
+            ipAddress.append(quad);
+        }
+
+        return ipAddress.toString();
+    }
+}