Add UncheckedFilterOutputStream.
MODIFY
src/changes/changes.xml
src/changes/changes.xml
@@ -69,6 +69,9 @@ The <action> type attribute can be add,update,fix,remove.
<action dev="ggregory" type="add" due-to="Gary Gregory">
Add UncheckedFilterInputStream.
</action>
+ <action dev="ggregory" type="add" due-to="Gary Gregory">
+ Add UncheckedFilterOutputStream.
+ </action>
<action dev="ggregory" type="add" due-to="Gary Gregory">
Add BrokenInputStream.INSTANCE.
</action>

ADD
src/main/java/org/apache/commons/io/output/UncheckedFilterOutputStream.java
+/*
+ * 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.commons.io.output;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.UncheckedIOException;
+
+/**
+ * A {@link FilterOutputStream} that throws {@link UncheckedIOException} instead of {@link UncheckedIOException}.
+ *
+ * @see FilterOutputStream
+ * @see UncheckedIOException
+ * @see UncheckedIOException
+ * @since 2.12.0
+ */
+public class UncheckedFilterOutputStream extends FilterOutputStream {
+
+ /**
+ * Creates a new instance.
+ *
+ * @param outputStream an OutputStream object providing the underlying stream.
+ * @return a new UncheckedFilterOutputStream.
+ */
+ public static UncheckedFilterOutputStream on(final OutputStream outputStream) {
+ return new UncheckedFilterOutputStream(outputStream);
+ }
+
+ /**
+ * Creates an output stream filter built on top of the specified underlying output stream.
+ *
+ * @param outputStream the underlying output stream, or {@code null} if this instance is to be created without an
+ * underlying stream.
+ */
+ public UncheckedFilterOutputStream(final OutputStream outputStream) {
+ super(outputStream);
+ }
+
+ /**
+ * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ public void close() throws UncheckedIOException {
+ try {
+ super.close();
+ } catch (final IOException e) {
+ uncheck(e);
+ }
+ }
+
+ private void uncheck(final IOException e) {
+ throw new UncheckedIOException(e);
+ }
+
+ /**
+ * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ public void flush() throws UncheckedIOException {
+ try {
+ super.flush();
+ } catch (final IOException e) {
+ uncheck(e);
+ }
+ }
+
+ /**
+ * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ public void write(final byte[] b) throws UncheckedIOException {
+ try {
+ super.write(b);
+ } catch (final IOException e) {
+ uncheck(e);
+ }
+ }
+
+ /**
+ * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ public void write(final byte[] b, final int off, final int len) throws UncheckedIOException {
+ try {
+ super.write(b, off, len);
+ } catch (final IOException e) {
+ uncheck(e);
+ }
+ }
+
+ /**
+ * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ public void write(final int b) throws UncheckedIOException {
+ try {
+ super.write(b);
+ } catch (final IOException e) {
+ uncheck(e);
+ }
+ }
+
+}

ADD
src/test/java/org/apache/commons/io/output/UncheckedFilterOutputStreamTest.java
+/*
+ * 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.commons.io.output;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
+import java.nio.charset.Charset;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+/**
+ * JUnit Test Case for {@link BrokenWriter}.
+ */
+public class UncheckedFilterOutputStreamTest {
+
+ private IOException exception;
+
+ private UncheckedFilterOutputStream brokenWriter;
+ private UncheckedFilterOutputStream stringWriter;
+
+ @SuppressWarnings("resource")
+ @BeforeEach
+ public void setUp() {
+ exception = new IOException("test exception");
+ brokenWriter = UncheckedFilterOutputStream.on(new BrokenOutputStream(exception));
+ stringWriter = UncheckedFilterOutputStream.on(new WriterOutputStream(new StringWriter(), Charset.defaultCharset()));
+ }
+
+ @Test
+ public void testClose() {
+ stringWriter.close();
+ }
+
+ @Test
+ public void testCloseThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.close()).getCause());
+ }
+
+ @Test
+ public void testEquals() {
+ stringWriter.equals(null);
+ }
+
+ @Test
+ @Disabled("What should happen here?")
+ public void testEqualsThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.equals(null)).getCause());
+ }
+
+ @Test
+ public void testFlush() {
+ stringWriter.flush();
+ }
+
+ @Test
+ public void testFlushThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.flush()).getCause());
+ }
+
+ @Test
+ public void testHashCode() {
+ stringWriter.hashCode();
+ }
+
+ @Test
+ @Disabled("What should happen here?")
+ public void testHashCodeThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.hashCode()).getCause());
+ }
+
+ @Test
+ public void testToString() {
+ stringWriter.toString();
+ }
+
+ @Test
+ @Disabled("What should happen here?")
+ public void testToStringThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.toString()).getCause());
+ }
+
+ @Test
+ public void testWriteInt() {
+ stringWriter.write(1);
+ }
+
+ @Test
+ public void testWriteIntThrows() {
+ assertEquals(exception, assertThrows(UncheckedIOException.class, () -> brokenWriter.write(1)).getCause());
+ }
+
+}

Add UncheckedFilterOutputStream.