Support self-inclusive binary prefixes

jpos/src/main/java/org/jpos/iso/ISOBinaryFieldPackager.java

@@ -18,6 +18,9 @@
 
 package org.jpos.iso;
 
+import org.jpos.iso.packager.GenericPackagerParams;
+import org.xml.sax.Attributes;
+
 import java.io.IOException;
 import java.io.InputStream;
 
@@ -26,7 +29,7 @@
  * @author joconnor
  * @version $Revision$ $Date$
  */
-public class ISOBinaryFieldPackager extends ISOFieldPackager
+public class ISOBinaryFieldPackager extends ISOFieldPackager implements GenericPackagerParams
 {
     private BinaryInterpreter interpreter;
     private Prefixer prefixer;
@@ -88,6 +91,22 @@ public void setPrefixer(Prefixer prefixer)
         this.prefixer = prefixer;
     }
 
+    /**
+     * Supports the {@code inclusive="true"} GenericPackager attribute for
+     * one- and two-byte binary length prefixes.
+     */
+    @Override
+    public void setGenericPackagerParams(Attributes atts) {
+        if (!Boolean.parseBoolean(atts.getValue("inclusive")))
+            return;
+        if (prefixer == BinaryPrefixer.B)
+            prefixer = SelfInclusiveBinaryPrefixer.B;
+        else if (prefixer == BinaryPrefixer.BB)
+            prefixer = SelfInclusiveBinaryPrefixer.BB;
+        else
+            throw new IllegalArgumentException("The inclusive attribute requires a binary length prefix");
+    }
+
     public int getMaxPackedLength()
     {
         return prefixer.getPackedLength() + interpreter.getPackedLength(getLength());

jpos/src/main/java/org/jpos/iso/SelfInclusiveBinaryPrefixer.java

@@ -0,0 +1,61 @@
+/*
+ * jPOS Project [http://jpos.org]
+ * Copyright (C) 2000-2026 jPOS Software SRL
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.jpos.iso;
+
+/**
+ * Binary prefixer whose encoded length includes the length prefix itself.
+ */
+public class SelfInclusiveBinaryPrefixer implements Prefixer {
+    /** A self-inclusive, one-byte binary length prefixer. */
+    public static final SelfInclusiveBinaryPrefixer B = new SelfInclusiveBinaryPrefixer(BinaryPrefixer.B);
+
+    /** A self-inclusive, two-byte binary length prefixer. */
+    public static final SelfInclusiveBinaryPrefixer BB = new SelfInclusiveBinaryPrefixer(BinaryPrefixer.BB);
+
+    private final BinaryPrefixer prefixer;
+
+    private SelfInclusiveBinaryPrefixer(BinaryPrefixer prefixer) {
+        this.prefixer = prefixer;
+    }
+
+    @Override
+    public void encodeLength(int length, byte[] b) throws ISOException {
+        int inclusiveLength = length + getPackedLength();
+        if (inclusiveLength > maxLength())
+            throw new ISOException("invalid len " + length + " for a self-inclusive binary prefix");
+        prefixer.encodeLength(inclusiveLength, b);
+    }
+
+    @Override
+    public int decodeLength(byte[] b, int offset) throws ISOException {
+        int inclusiveLength = prefixer.decodeLength(b, offset);
+        if (inclusiveLength < getPackedLength())
+            throw new ISOException("invalid self-inclusive binary prefix " + inclusiveLength);
+        return inclusiveLength - getPackedLength();
+    }
+
+    @Override
+    public int getPackedLength() {
+        return prefixer.getPackedLength();
+    }
+
+    private int maxLength() {
+        return getPackedLength() == 1 ? 0xFF : 0xFFFF;
+    }
+}

jpos/src/main/java/org/jpos/iso/packager/GenericPackager.java

@@ -481,6 +481,8 @@ else if (localName.equals("isofield"))
                     f.setLength(Integer.parseInt(size));
                     f.setPad(Boolean.parseBoolean(pad));
                     f.setTrim(Boolean.parseBoolean(trim));
+                    if (f instanceof GenericPackagerParams)
+                        ((GenericPackagerParams)f).setGenericPackagerParams(atts);
                     // Modified for using TaggedFieldPackager
                     if( f instanceof TaggedFieldPackager){
                       ((TaggedFieldPackager)f).setToken( token );

jpos/src/main/resources/org/jpos/iso/packager/genericpackager.dtd

@@ -19,6 +19,7 @@
 <!ATTLIST isofield token  CDATA        #IMPLIED>
 <!ATTLIST isofield pad    (true|false) #IMPLIED>
 <!ATTLIST isofield trim (true|false) #IMPLIED>
+<!ATTLIST isofield inclusive (true|false) #IMPLIED>
 
 <!-- isofieldpackager -->
 <!ELEMENT isofieldpackager (isofield*,isofieldpackager*)*>
@@ -39,3 +40,4 @@
 <!ATTLIST isofieldpackager tagSize       CDATA        #IMPLIED>
 <!ATTLIST isofieldpackager lenSize       CDATA        #IMPLIED>
 <!ATTLIST isofieldpackager swapTagAndLen (true|false) #IMPLIED>
+<!ATTLIST isofieldpackager inclusive (true|false) #IMPLIED>

jpos/src/test/java/org/jpos/iso/SelfInclusiveBinaryPrefixerTest.java

@@ -0,0 +1,43 @@
+/*
+ * jPOS Project [http://jpos.org]
+ * Copyright (C) 2000-2026 jPOS Software SRL
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.jpos.iso;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class SelfInclusiveBinaryPrefixerTest {
+    @Test
+    void encodesAndDecodesOneByteLengths() throws Exception {
+        byte[] prefix = new byte[1];
+        SelfInclusiveBinaryPrefixer.B.encodeLength(10, prefix);
+
+        assertEquals(11, prefix[0] & 0xFF);
+        assertEquals(10, SelfInclusiveBinaryPrefixer.B.decodeLength(prefix, 0));
+    }
+
+    @Test
+    void encodesAndDecodesTwoByteLengths() throws Exception {
+        byte[] prefix = new byte[2];
+        SelfInclusiveBinaryPrefixer.BB.encodeLength(10, prefix);
+
+        assertEquals(12, (prefix[0] & 0xFF) * 256 + (prefix[1] & 0xFF));
+        assertEquals(10, SelfInclusiveBinaryPrefixer.BB.decodeLength(prefix, 0));
+    }
+}

jpos/src/test/java/org/jpos/iso/packager/GenericPackagerTest.java

@@ -18,6 +18,7 @@
 
 package org.jpos.iso.packager;
 
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
@@ -30,6 +31,7 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.FileNotFoundException;
+import java.nio.charset.StandardCharsets;
 import java.util.EmptyStackException;
 
 import org.jpos.core.Configuration;
@@ -39,6 +41,7 @@
 import org.jpos.iso.IFA_AMOUNT;
 import org.jpos.iso.IFA_BITMAP;
 import org.jpos.iso.ISOException;
+import org.jpos.iso.ISOBinaryField;
 import org.jpos.iso.ISOFieldPackager;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
@@ -51,6 +54,23 @@
 
 public class GenericPackagerTest {
 
+    @Test
+    public void testInclusiveBinaryField() throws Exception {
+        String xml = "<!DOCTYPE isopackager PUBLIC \"-//jPOS/jPOS Generic Packager DTD 1.0//EN\" \"http://jpos.org/dtd/generic-packager-1.0.dtd\">"
+            + "<isopackager>"
+            + "<isofield id=\"126\" length=\"10\" name=\"Private\" class=\"org.jpos.iso.IFB_LLHBINARY\" inclusive=\"true\"/>"
+            + "</isopackager>";
+        GenericPackager packager = new GenericPackager(new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8)));
+
+        ISOFieldPackager fieldPackager = packager.getFieldPackager(126);
+        byte[] packed = fieldPackager.pack(new ISOBinaryField(126, new byte[] { 0x12, 0x34 }));
+        assertEquals(3, packed[0] & 0xFF);
+
+        ISOBinaryField unpacked = new ISOBinaryField(126);
+        assertEquals(3, fieldPackager.unpack(unpacked, packed, 0));
+        assertArrayEquals(new byte[] { 0x12, 0x34 }, (byte[]) unpacked.getValue());
+    }
+
     @Test
     public void testConstructor() throws Throwable {
         GenericPackager genericPackager = new GenericPackager();