fixed ReadLength implementation

plc4j/protocols/ads/src/main/java/org/apache/plc4x/java/ads/api/commands/types/ReadLength.java

@@ -31,11 +31,26 @@ public class ReadLength extends ByteValue {
         assertLength(NUM_BYTES);
     }
 
-    public static ReadLength of(int length) {
-        return new ReadLength(ByteBuffer.allocate(NUM_BYTES).putInt(length).array());
+    public static ReadLength of(long length) {
+        checkUnsignedBounds(length, NUM_BYTES);
+        return new ReadLength(ByteBuffer.allocate(NUM_BYTES)
+            .put((byte) (length >> 24 & 0xff))
+            .put((byte) (length >> 16 & 0xff))
+            .put((byte) (length >> 8 & 0xff))
+            .put((byte) (length & 0xff))
+            .array());
+    }
+
+    public static ReadLength of(String length) {
+        return of(Long.parseLong(length));
     }
 
     public static ReadLength of(byte... values) {
         return new ReadLength(values);
     }
+
+    @Override
+    public String toString() {
+        return "" + (getBytes()[0] << 24 | getBytes()[1] << 16 | getBytes()[2] << 8 | getBytes()[3]);
+    }
 }

plc4j/protocols/ads/src/test/java/org/apache/plc4x/java/ads/api/commands/types/ReadLengthTest.java

@@ -0,0 +1,55 @@
+/*
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements.  See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership.  The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License.  You may obtain a copy of the License at
+ 
+   http://www.apache.org/licenses/LICENSE-2.0
+ 
+ Unless required by applicable law or agreed to in writing,
+ software distributed under the License is distributed on an
+ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ KIND, either express or implied.  See the License for the
+ specific language governing permissions and limitations
+ under the License.
+ */
+package org.apache.plc4x.java.ads.api.commands.types;
+
+import org.apache.commons.codec.binary.Hex;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class ReadReadLengthTest {
+    byte NULL_BYTE = 0x0;
+
+    @Test
+    void ofBytes() {
+        Assertions.assertEquals("0", ReadLength.of(NULL_BYTE, NULL_BYTE, NULL_BYTE, NULL_BYTE).toString());
+        Assertions.assertThrows(IllegalArgumentException.class, () -> ReadLength.of(NULL_BYTE, NULL_BYTE, NULL_BYTE, NULL_BYTE, NULL_BYTE));
+    }
+
+    @Test
+    void ofLong() {
+        assertByte(ReadLength.of(1), "0x00000001");
+        assertByte(ReadLength.of(65535), "0x0000ffff");
+        Assertions.assertThrows(IllegalArgumentException.class, () -> ReadLength.of(-1));
+        Assertions.assertThrows(IllegalArgumentException.class, () -> ReadLength.of(Long.valueOf("4294967296")));
+    }
+
+    @Test
+    void ofString() {
+        assertByte(ReadLength.of("1"), "0x00000001");
+    }
+
+    @Test
+    void testToString() {
+        Assertions.assertEquals(ReadLength.of("1").toString(), "1");
+    }
+
+    void assertByte(ReadLength actual, String expected) {
+        Assertions.assertEquals(expected, "0x" + Hex.encodeHexString(actual.getBytes()));
+    }
+}