Add UncheckedAppendable.
MODIFY
src/changes/changes.xml
src/changes/changes.xml
@@ -120,6 +120,9 @@ The <action> type attribute can be add,update,fix,remove.
<action dev="ggregory" type="add" due-to="Gary Gregory">
Add PathUtils.newOutputStream(Path, boolean).
</action>
+ <action dev="ggregory" type="add" due-to="Gary Gregory">
+ Add UncheckedAppendable.
+ </action>
<!-- UPDATE -->
<action dev="ggregory" type="update" due-to="Dependabot">
Bump Maven Javadoc plugin from 3.2.0 to 3.3.0.

ADD
src/main/java/org/apache/commons/io/output/UncheckedAppendable.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.IOException;
+import java.io.UncheckedIOException;
+
+/**
+ * An {@link Appendable} that throws {@link UncheckedIOException} instead of {@link IOException}.
+ *
+ * @see Appendable
+ * @see IOException
+ * @see UncheckedIOException
+ * @since 2.12.0
+ */
+public interface UncheckedAppendable extends Appendable {
+
+ /**
+ * Creates a new instance on the given Appendable.
+ *
+ * @param appendable The Appendable to uncheck.
+ * @return a new instance.
+ */
+ public static UncheckedAppendable on(final Appendable appendable) {
+ return new UncheckedAppendableImpl(appendable);
+ }
+
+ /**
+ * Rethrows {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ UncheckedAppendable append(char c);
+
+ /**
+ * Rethrows {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ UncheckedAppendable append(CharSequence csq);
+
+ /**
+ * Rethrows {@link IOException} as {@link UncheckedIOException}.
+ */
+ @Override
+ UncheckedAppendable append(CharSequence csq, int start, int end);
+}

ADD
src/main/java/org/apache/commons/io/output/UncheckedAppendableImpl.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.IOException;
+import java.io.UncheckedIOException;
+import java.util.Objects;
+
+/**
+ * An {@link Appendable} implementation that throws {@link UncheckedIOException} instead of {@link IOException}.
+ *
+ * @see Appendable
+ * @see IOException
+ * @see UncheckedIOException
+ * @since 2.12.0
+ */
+class UncheckedAppendableImpl implements UncheckedAppendable {
+
+ private final Appendable appendable;
+
+ UncheckedAppendableImpl(final Appendable appendable) {
+ super();
+ this.appendable = Objects.requireNonNull(appendable, "appendable");
+ }
+
+ @Override
+ public UncheckedAppendable append(final char c) {
+ try {
+ appendable.append(c);
+ } catch (final IOException e) {
+ throw new UncheckedIOException(String.valueOf(c), e);
+ }
+ return this;
+ }
+
+ @Override
+ public UncheckedAppendable append(final CharSequence csq) {
+ try {
+ appendable.append(csq);
+ } catch (final IOException e) {
+ throw new UncheckedIOException(Objects.toString(csq), e);
+ }
+ return this;
+ }
+
+ @Override
+ public UncheckedAppendable append(final CharSequence csq, final int start, final int end) {
+ try {
+ appendable.append(csq, start, end);
+ } catch (final IOException e) {
+ throw new UncheckedIOException(Objects.toString(csq), e);
+ }
+ return this;
+ }
+
+ @Override
+ public String toString() {
+ return appendable.toString();
+ }
+
+}
\ No newline at end of file

ADD
src/test/java/org/apache/commons/io/output/UncheckedAppendableTest.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.fail;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * JUnit Test Case for {@link BrokenWriter}.
+ */
+public class UncheckedAppendableTest {
+
+ private IOException exception;
+
+ private UncheckedAppendable appendableBroken;
+ private UncheckedAppendable appendableString;
+
+ @SuppressWarnings("resource")
+ @BeforeEach
+ public void setUp() {
+ exception = new IOException("test exception");
+ appendableBroken = UncheckedAppendable.on(new BrokenWriter(exception));
+ appendableString = UncheckedAppendable.on(new StringWriter());
+ }
+
+ @Test
+ public void testAppendChar() {
+ appendableString.append('a').append('b');
+ assertEquals("ab", appendableString.toString());
+ }
+
+ @Test
+ public void testAppendCharSequence() {
+ appendableString.append("a").append("b");
+ assertEquals("ab", appendableString.toString());
+ }
+
+ @Test
+ public void testAppendCharSequenceIndexed() {
+ appendableString.append("a", 0, 1).append("b", 0, 1);
+ assertEquals("ab", appendableString.toString());
+ }
+
+ @Test
+ public void testAppendCharSequenceIndexedThrows() {
+ try {
+ appendableBroken.append("a", 0, 1);
+ fail("Expected exception not thrown.");
+ } catch (final UncheckedIOException e) {
+ assertEquals(exception, e.getCause());
+ }
+ }
+
+ @Test
+ public void testAppendCharSequenceThrows() {
+ try {
+ appendableBroken.append("a");
+ fail("Expected exception not thrown.");
+ } catch (final UncheckedIOException e) {
+ assertEquals(exception, e.getCause());
+ }
+ }
+
+ @Test
+ public void testAppendCharThrows() {
+ try {
+ appendableBroken.append('a');
+ fail("Expected exception not thrown.");
+ } catch (final UncheckedIOException e) {
+ assertEquals(exception, e.getCause());
+ }
+ }
+
+ @Test
+ public void testToString() {
+ assertEquals("ab", UncheckedAppendable.on(new StringWriter(2).append("ab")).toString());
+ }
+
+}

Add UncheckedAppendable.