Add IOUtils.copy(URL, File) and copy(URL, OutputStream).

Author: Gary Gregory

src/changes/changes.xml

@@ -175,6 +175,12 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="add" due-to="Gary Gregory">
         Make public and reuse IOUtils.EMPTY_BYTE_ARRAY.
       </action>
+      <action dev="ggregory" type="add" due-to="Gary Gregory">
+        Add IOUtils.copy(URL, File).
+      </action>
+      <action dev="ggregory" type="add" due-to="Gary Gregory">
+        Add copy(URL, OutputStream).
+      </action>
       <!-- UPDATES -->
       <action dev="ggregory" type="update" due-to="Dependabot">
         Update junit-jupiter from 5.6.2 to 5.7.0 #153.

src/main/java/org/apache/commons/io/IOUtils.java

@@ -25,6 +25,7 @@
 import java.io.Closeable;
 import java.io.EOFException;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -1190,6 +1191,52 @@ public static int copy(final Reader reader, final Writer writer) throws IOExcept
         return (int) count;
     }
 
+    /**
+     * Copies bytes from a {@code URL} to an {@code OutputStream}.
+     * <p>
+     * This method buffers the input internally, so there is no need to use a {@code BufferedInputStream}.
+     * </p>
+     * <p>
+     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
+     * </p>
+     *
+     * @param url the {@code URL} to read.
+     * @param file the {@code OutputStream} to write.
+     * @return the number of bytes copied.
+     * @throws NullPointerException if the URL is {@code null}.
+     * @throws NullPointerException if the OutputStream is {@code null}.
+     * @throws IOException if an I/O error occurs.
+     * @since 2.9.0
+     */
+    public static long copy(final URL url, final File file) throws IOException {
+        try (FileOutputStream outputStream = new FileOutputStream(Objects.requireNonNull(file, "file"))) {
+            return copy(url, outputStream);
+        }
+    }
+
+    /**
+     * Copies bytes from a {@code URL} to an {@code OutputStream}.
+     * <p>
+     * This method buffers the input internally, so there is no need to use a {@code BufferedInputStream}.
+     * </p>
+     * <p>
+     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
+     * </p>
+     *
+     * @param url the {@code URL} to read.
+     * @param outputStream the {@code OutputStream} to write.
+     * @return the number of bytes copied.
+     * @throws NullPointerException if the URL is {@code null}.
+     * @throws NullPointerException if the OutputStream is {@code null}.
+     * @throws IOException if an I/O error occurs.
+     * @since 2.9.0
+     */
+    public static long copy(final URL url, final OutputStream outputStream) throws IOException {
+        try (InputStream inputStream = Objects.requireNonNull(url, "url").openStream()) {
+            return copyLarge(inputStream, outputStream);
+        }
+    }
+
     /**
      * Copies bytes from a large (over 2GB) {@code InputStream} to an
      * {@code OutputStream}.

src/test/java/org/apache/commons/io/IOUtilsCopyTestCase.java

@@ -16,7 +16,9 @@
  */
 package org.apache.commons.io;
 
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -27,7 +29,11 @@
 import java.io.OutputStreamWriter;
 import java.io.Reader;
 import java.io.Writer;
+import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.Arrays;
 
 import org.apache.commons.io.input.NullInputStream;
@@ -431,4 +437,32 @@ public void testCopy_readerToWriter_nullOut() {
         assertThrows(NullPointerException.class, () -> IOUtils.copy(reader, (Writer) null));
     }
 
+    @Test
+    public void testCopy_URLToFile() throws Exception {
+        final String name = "/org/apache/commons/io/abitmorethan16k.txt";
+        URL in = getClass().getResource(name);
+        assertNotNull(in, name);
+
+        Path path = Files.createTempFile("testCopy_URLToFile", ".txt");
+        try {
+            IOUtils.copy(in, path.toFile());
+
+            assertArrayEquals(Files.readAllBytes(Paths.get("src/test/resources" + name)), Files.readAllBytes(path));
+        } finally {
+            Files.delete(path);
+        }
+    }
+
+    @Test
+    public void testCopy_URLToOutputStream() throws Exception {
+        final String name = "/org/apache/commons/io/abitmorethan16k.txt";
+        URL in = getClass().getResource(name);
+        assertNotNull(in, name);
+
+        final ByteArrayOutputStream baout = new ByteArrayOutputStream();
+        IOUtils.copy(in, baout);
+
+        assertArrayEquals(Files.readAllBytes(Paths.get("src/test/resources" + name)), baout.toByteArray());
+    }
+
 }