Add HexDumpUtil for formatted test output

Author: vanitasvitae

pg/src/test/java/org/bouncycastle/bcpg/HexDumpUtil.java

@@ -0,0 +1,83 @@
+package org.bouncycastle.bcpg;
+
+import org.bouncycastle.util.encoders.Hex;
+
+import java.io.IOException;
+
+public class HexDumpUtil {
+
+    /**
+     * Return a formatted hex dump of the given byte array.
+     * @param array byte array
+     */
+    public static String hexdump(byte[] array) {
+        return hexdump(0, array);
+    }
+
+    /**
+     * Return a formatted hex dump of the given byte array.
+     * If startIndent is non-zero, the dump is shifted right by startIndent octets.
+     * @param startIndent shift the octet stream between by a number of bytes
+     * @param array byte array
+     */
+    public static String hexdump(int startIndent, byte[] array) {
+        if (startIndent < 0) {
+            throw new IllegalArgumentException("Start-Indent must be a positive number");
+        }
+        if (array == null) {
+            return "<null>";
+        }
+        String hex = Hex.toHexString(array);
+        StringBuilder withWhiteSpace = new StringBuilder();
+        // shift the dump a number of octets to the right
+        for (int i = 0; i < startIndent; i++) {
+            withWhiteSpace.append("  ");
+        }
+        // Split into hex octets (pairs of two chars)
+        String[] octets = withWhiteSpace.append(hex).toString().split("(?<=\\G.{2})");
+
+        StringBuilder out = new StringBuilder();
+        int l = 0;
+        while (l < octets.length) {
+            // index row
+            out.append(String.format("%08X", l)).append("  ");
+            // first 8 octets of a line
+            for (int i = l ; i < l + 8 && i < octets.length; i++) {
+                out.append(octets[i]).append(" ");
+            }
+            out.append(" ");
+            // second 8 octets of a line
+            for (int i = l+8; i < l + 16 && i < octets.length; i++) {
+                out.append(octets[i]).append(" ");
+            }
+            out.append("\n");
+
+            l += 16;
+        }
+        return out.toString();
+    }
+
+    /**
+     * Return a formatted hex dump of the packet encoding of the given packet.
+     * @param packet packet
+     * @return formatted hex dump
+     * @throws IOException if an exception happens during packet encoding
+     */
+    public static String hexdump(ContainedPacket packet)
+            throws IOException {
+        return hexdump(packet.getEncoded());
+    }
+
+    /**
+     * Return a formatted hex dump of the packet encoding of the given packet.
+     * If startIndent is non-zero, the hex dump is shifted right by the startIndent octets.
+     * @param startIndent shift the encodings octet stream by a number of bytes
+     * @param packet packet
+     * @return formatted hex dump
+     * @throws IOException if an exception happens during packet encoding
+     */
+    public static String hexdump(int startIndent, ContainedPacket packet)
+            throws IOException {
+        return hexdump(startIndent, packet.getEncoded());
+    }
+}