Pull-up common Builder attributes to BaseNCodec

garydgregory · garydgregory · commit 3e27d960f6b3 · 2024-04-16T18:31:34.000-04:00
diff --git a/src/main/java/org/apache/commons/codec/binary/Base32.java b/src/main/java/org/apache/commons/codec/binary/Base32.java
@@ -288,14 +288,30 @@ public Base32(final int lineLength, final byte[] lineSeparator, final boolean us
      * @since 1.15
      */
     public Base32(final int lineLength, final byte[] lineSeparator, final boolean useHex, final byte padding, final CodecPolicy decodingPolicy) {
-        super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, lineSeparator == null ? 0 : lineSeparator.length, padding, decodingPolicy);
-        if (useHex) {
-            this.encodeTable = HEX_ENCODE_TABLE;
-            this.decodeTable = HEX_DECODE_TABLE;
-        } else {
-            this.encodeTable = ENCODE_TABLE;
-            this.decodeTable = DECODE_TABLE;
-        }
+        this(lineLength, lineSeparator, useHex ? HEX_ENCODE_TABLE : ENCODE_TABLE, padding, decodingPolicy);
+    }
+
+    /**
+     * Constructs a Base32 / Base32 Hex codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length and line separator are given in the constructor.
+     * </p>
+     * <p>
+     * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
+     * </p>
+     *
+     * @param lineLength     Each line of encoded data will be at most of the given length (rounded down to the nearest multiple of 8). If lineLength &lt;= 0,
+     *                       then the output will not be divided into lines (chunks). Ignored when decoding.
+     * @param lineSeparator  Each line of encoded data will end with this sequence of bytes.
+     * @param encodeTable    A Base32 alphabet.
+     * @param padding        byte used as padding byte.
+     * @param decodingPolicy The decoding policy.
+     * @throws IllegalArgumentException Thrown when the {@code lineSeparator} contains Base32 characters. Or the lineLength &gt; 0 and lineSeparator is null.
+     */
+    private Base32(final int lineLength, final byte[] lineSeparator, final byte[] encodeTable, final byte padding, final CodecPolicy decodingPolicy) {
+        super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, toLength(lineSeparator), padding, decodingPolicy);
+        this.encodeTable = encodeTable;
+        this.decodeTable = encodeTable == HEX_ENCODE_TABLE ? HEX_DECODE_TABLE : DECODE_TABLE;
         if (lineLength > 0) {
             if (lineSeparator == null) {
                 throw new IllegalArgumentException("lineLength " + lineLength + " > 0, but lineSeparator is null");
diff --git a/src/main/java/org/apache/commons/codec/binary/Base64.java b/src/main/java/org/apache/commons/codec/binary/Base64.java
@@ -20,7 +20,6 @@
 import java.math.BigInteger;
 import java.util.Arrays;
 import java.util.Objects;
-import java.util.function.Supplier;
 
 import org.apache.commons.codec.CodecPolicy;
 
@@ -62,27 +61,13 @@ public class Base64 extends BaseNCodec {
      *
      * @since 1.17.0
      */
-    public static class Builder implements Supplier<Base64> {
+    public static class Builder extends AbstractBuilder<Base64, Builder> {
 
-        private int lineLength;
-        private byte[] lineSeparator = CHUNK_SEPARATOR;
         private byte[] encodeTable = STANDARD_ENCODE_TABLE;
-        private CodecPolicy decodingPolicy = DECODING_POLICY_DEFAULT;
 
         @Override
         public Base64 get() {
-            return new Base64(lineLength, lineSeparator, encodeTable, decodingPolicy);
-        }
-
-        /**
-         * Sets the decoding policy.
-         *
-         * @param decodingPolicy the decoding policy, null resets to the default.
-         * @return this.
-         */
-        public Builder setDecodingPolicy(final CodecPolicy decodingPolicy) {
-            this.decodingPolicy = decodingPolicy != null ? decodingPolicy : DECODING_POLICY_DEFAULT;
-            return this;
+            return new Base64(getLineLength(), getLineSeparator(), encodeTable, getDecodingPolicy());
         }
 
         /**
@@ -96,28 +81,6 @@ public Builder setEncodeTable(final byte... encodeTable) {
             return this;
         }
 
-        /**
-         * Sets the line length.
-         *
-         * @param lineLength the line length, less than 0 resets to the default.
-         * @return this.
-         */
-        public Builder setLineLength(final int lineLength) {
-            this.lineLength = Math.max(0, lineLength);
-            return this;
-        }
-
-        /**
-         * Sets the line separator.
-         *
-         * @param lineSeparator the line separator, null resets to the default.
-         * @return this.
-         */
-        public Builder setLineSeparator(final byte... lineSeparator) {
-            this.lineSeparator = lineSeparator != null ? lineSeparator : CHUNK_SEPARATOR;
-            return this;
-        }
-
         /**
          * Sets the URL-safe encoding policy.
          *
@@ -561,6 +524,7 @@ public Base64(final boolean urlSafe) {
         this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
     }
 
+
     /**
      * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
      * <p>
@@ -584,7 +548,6 @@ public Base64(final int lineLength) {
         this(lineLength, CHUNK_SEPARATOR);
     }
 
-
     /**
      * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
      * <p>
@@ -702,9 +665,8 @@ public Base64(final int lineLength, final byte[] lineSeparator, final boolean ur
      *             Thrown when the {@code lineSeparator} contains Base64 characters.
      */
     private Base64(final int lineLength, final byte[] lineSeparator, final byte[] encodeTable, final CodecPolicy decodingPolicy) {
-        super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, lineSeparator == null ? 0 : lineSeparator.length, PAD_DEFAULT, decodingPolicy);
+        super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, toLength(lineSeparator), PAD_DEFAULT, decodingPolicy);
         this.encodeTable = Objects.requireNonNull(encodeTable, "encodeTable");
-
         if (encodeTable == STANDARD_ENCODE_TABLE || encodeTable == URL_SAFE_ENCODE_TABLE) {
             decodeTable = DECODE_TABLE;
         } else {
diff --git a/src/main/java/org/apache/commons/codec/binary/BaseNCodec.java b/src/main/java/org/apache/commons/codec/binary/BaseNCodec.java
@@ -19,6 +19,7 @@
 
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.function.Supplier;
 
 import org.apache.commons.codec.BinaryDecoder;
 import org.apache.commons.codec.BinaryEncoder;
@@ -51,12 +52,75 @@
  */
 public abstract class BaseNCodec implements BinaryEncoder, BinaryDecoder {
 
+    /**
+     * Builds {@link Base64} instances.
+     *
+     * @param <T> the codec type to build.
+     * @param <B> the codec builder subtype.
+     * @since 1.17.0
+     */
+    public abstract static class AbstractBuilder<T, B extends AbstractBuilder<T, B>> implements Supplier<T> {
+
+        private CodecPolicy decodingPolicy = DECODING_POLICY_DEFAULT;
+        private int lineLength;
+        private byte[] lineSeparator = CHUNK_SEPARATOR;
+
+        @SuppressWarnings("unchecked")
+        B asThis() {
+            return (B) this;
+        }
+
+        CodecPolicy getDecodingPolicy() {
+            return decodingPolicy;
+        }
+
+        int getLineLength() {
+            return lineLength;
+        }
+
+        byte[] getLineSeparator() {
+            return lineSeparator;
+        }
+
+        /**
+         * Sets the decoding policy.
+         *
+         * @param decodingPolicy the decoding policy, null resets to the default.
+         * @return this.
+         */
+        public B setDecodingPolicy(final CodecPolicy decodingPolicy) {
+            this.decodingPolicy = decodingPolicy != null ? decodingPolicy : DECODING_POLICY_DEFAULT;
+            return asThis();
+        }
+
+        /**
+         * Sets the line length.
+         *
+         * @param lineLength the line length, less than 0 resets to the default.
+         * @return this.
+         */
+        public B setLineLength(final int lineLength) {
+            this.lineLength = Math.max(0, lineLength);
+            return asThis();
+        }
+
+        /**
+         * Sets the line separator.
+         *
+         * @param lineSeparator the line separator, null resets to the default.
+         * @return this.
+         */
+        public B setLineSeparator(final byte... lineSeparator) {
+            this.lineSeparator = lineSeparator != null ? lineSeparator : CHUNK_SEPARATOR;
+            return asThis();
+        }
+
+    }
+
     /**
      * Holds thread context so classes can be thread-safe.
      *
      * This class is not itself thread-safe; each thread must allocate its own copy.
-     *
-     * @since 1.7
      */
     static class Context {
 
@@ -110,7 +174,6 @@ static class Context {
          *
          * @return a String useful for debugging.
          */
-        @SuppressWarnings("boxing") // OK to ignore boxing here
         @Override
         public String toString() {
             return String.format("%s[buffer=%s, currentLinePos=%s, eof=%s, ibitWorkArea=%s, lbitWorkArea=%s, " +
@@ -263,6 +326,16 @@ private static byte[] resizeBuffer(final Context context, final int minCapacity)
         return b;
     }
 
+    /**
+     * Gets the array length or 0 if null.
+     *
+     * @param array the array or null.
+     * @return the array length or 0 if null.
+     */
+    static int toLength(final byte[] array) {
+        return array == null ? 0 : array.length;
+    }
+
     /**
      * @deprecated Use {@link #pad}. Will be removed in 2.0.
      */
