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Posted to commits@commons.apache.org by gg...@apache.org on 2019/08/09 14:41:57 UTC
[commons-io] branch master updated: Added AppendableWriter. (#87)
This is an automated email from the ASF dual-hosted git repository.
ggregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-io.git
The following commit(s) were added to refs/heads/master by this push:
new bae3ef5 Added AppendableWriter. (#87)
bae3ef5 is described below
commit bae3ef5c23f46f8458da105ee3864b356a2007e3
Author: Rob Spoor <ro...@users.noreply.github.com>
AuthorDate: Fri Aug 9 16:41:53 2019 +0200
Added AppendableWriter. (#87)
* Added AppendableWriter.
* Added IOUtils.writer method.
---
src/main/java/org/apache/commons/io/IOUtils.java | 22 +++
.../apache/commons/io/output/AppendableWriter.java | 162 +++++++++++++++++++++
.../org/apache/commons/io/IOUtilsTestCase.java | 29 ++++
.../commons/io/output/AppendableWriterTest.java | 88 +++++++++++
4 files changed, 301 insertions(+)
diff --git a/src/main/java/org/apache/commons/io/IOUtils.java b/src/main/java/org/apache/commons/io/IOUtils.java
index 12a44dc..64240f2 100644
--- a/src/main/java/org/apache/commons/io/IOUtils.java
+++ b/src/main/java/org/apache/commons/io/IOUtils.java
@@ -47,7 +47,9 @@ import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
+import java.util.Objects;
+import org.apache.commons.io.output.AppendableWriter;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.commons.io.output.StringBuilderWriter;
@@ -296,6 +298,26 @@ public class IOUtils {
}
/**
+ * Returns the given Appendable if it is already a {@link Writer}, otherwise creates a Writer wrapper around the
+ * given Appendable.
+ *
+ * @param appendable the Appendable to wrap or return (not null)
+ * @return the given Appendable or a Writer wrapper around the given Appendable
+ * @throws NullPointerException if the input parameter is null
+ * @since 2.7
+ */
+ public static Writer writer(final Appendable appendable) {
+ Objects.requireNonNull(appendable, "appendable");
+ if (appendable instanceof Writer) {
+ return (Writer) appendable;
+ }
+ if (appendable instanceof StringBuilder) {
+ return new StringBuilderWriter((StringBuilder) appendable);
+ }
+ return new AppendableWriter<>(appendable);
+ }
+
+ /**
* Closes a URLConnection.
*
* @param conn the connection to close.
diff --git a/src/main/java/org/apache/commons/io/output/AppendableWriter.java b/src/main/java/org/apache/commons/io/output/AppendableWriter.java
new file mode 100644
index 0000000..93b2d4f
--- /dev/null
+++ b/src/main/java/org/apache/commons/io/output/AppendableWriter.java
@@ -0,0 +1,162 @@
+/*
+ * 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.Writer;
+import java.util.Objects;
+
+/**
+ * Writer implementation that writes the data to an {@link Appendable}
+ * Object.
+ * <p>
+ * For example, can be used with a {@link java.lang.StringBuilder}
+ * or {@link java.lang.StringBuffer}.
+ *
+ * @since 2.7
+ * @see java.lang.Appendable
+ *
+ * @param <T> The type of the {@link Appendable} wrapped by this AppendableWriter.
+ */
+public class AppendableWriter <T extends Appendable> extends Writer {
+
+ private final T appendable;
+
+ /**
+ * Construct a new instance with the specified appendable.
+ *
+ * @param appendable the appendable to write to
+ */
+ public AppendableWriter(final T appendable) {
+ this.appendable = appendable;
+ }
+
+ /**
+ * Write a character to the underlying appendable.
+ *
+ * @param c the character to write
+ * @throws IOException upon error
+ */
+ @Override
+ public void write(final int c) throws IOException {
+ appendable.append((char)c);
+ }
+
+ /**
+ * Writes a portion of an array of characters to the underlying appendable.
+ *
+ * @param cbuf an array with the characters to write
+ * @param off offset from which to start writing characters
+ * @param len number of characters to write
+ * @throws IOException upon error
+ */
+ @Override
+ public void write(final char[] cbuf, final int off, final int len) throws IOException {
+ Objects.requireNonNull(cbuf, "Character array is missing");
+ if (len < 0 || (off + len) > cbuf.length) {
+ throw new IndexOutOfBoundsException("Array Size=" + cbuf.length +
+ ", offset=" + off + ", length=" + len);
+ }
+ for (int i = 0; i < len; i++) {
+ appendable.append(cbuf[off + i]);
+ }
+ }
+
+ /**
+ * Writes a portion of a String to the underlying appendable.
+ *
+ * @param str a string
+ * @param off offset from which to start writing characters
+ * @param len number of characters to write
+ * @throws IOException upon error
+ */
+ @Override
+ public void write(final String str, final int off, final int len) throws IOException {
+ // appendable.append will add "null" for a null String; add an explicit null check
+ Objects.requireNonNull(str, "String is missing");
+ appendable.append(str, off, off + len);
+ }
+
+ /**
+ * Appends the specified character sequence to the underlying appendable.
+ *
+ * @param csq the character sequence to append
+ * @return this writer
+ * @throws IOException upon error
+ */
+ @Override
+ public Writer append(final CharSequence csq) throws IOException {
+ appendable.append(csq);
+ return this;
+ }
+
+ /**
+ * Appends a subsequence of the specified character sequence to the underlying appendable.
+ *
+ * @param csq the character sequence from which a subsequence will be appended
+ * @param start the index of the first character in the subsequence
+ * @param end the index of the character following the last character in the subsequence
+ * @return this writer
+ * @throws IOException upon error
+ */
+ @Override
+ public Writer append(final CharSequence csq, final int start, final int end) throws IOException {
+ appendable.append(csq, start, end);
+ return this;
+ }
+
+ /**
+ * Appends the specified character to the underlying appendable.
+ *
+ * @param c the character to append
+ * @return this writer
+ * @throws IOException upon error
+ */
+ @Override
+ public Writer append(final char c) throws IOException {
+ appendable.append(c);
+ return this;
+ }
+
+ /**
+ * Flushes the stream. This implementation does nothing.
+ *
+ * @throws IOException upon error
+ */
+ @Override
+ public void flush() throws IOException {
+ }
+
+ /**
+ * Closes the stream. This implementation does nothing.
+ *
+ * @throws IOException upon error
+ */
+ @Override
+ public void close() throws IOException {
+ }
+
+ /**
+ * Return the target appendable.
+ *
+ * @return the target appendable
+ */
+ public T getAppendable() {
+ return appendable;
+ }
+
+}
diff --git a/src/test/java/org/apache/commons/io/IOUtilsTestCase.java b/src/test/java/org/apache/commons/io/IOUtilsTestCase.java
index 0058133..f5b5d9d 100644
--- a/src/test/java/org/apache/commons/io/IOUtilsTestCase.java
+++ b/src/test/java/org/apache/commons/io/IOUtilsTestCase.java
@@ -58,6 +58,8 @@ import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;
+import org.apache.commons.io.output.AppendableWriter;
+import org.apache.commons.io.output.StringBuilderWriter;
import org.apache.commons.io.testtools.TestUtils;
import org.junit.Assert;
import org.junit.Before;
@@ -1514,6 +1516,33 @@ public class IOUtilsTestCase {
assertSame(bw, IOUtils.buffer(bw, 1024));
}
+ @Test
+ public void testAsWriterNull() {
+ try {
+ IOUtils.writer(null);
+ fail("Expected NullPointerException");
+ } catch (final NullPointerException npe) {
+ // expected
+ }
+ }
+
+ @Test
+ public void testAsWriterStringBuilder() {
+ final Appendable a = new StringBuilder();
+ final Writer w = IOUtils.writer(a);
+ assertNotSame(w, a);
+ assertEquals(StringBuilderWriter.class, w.getClass());
+ assertSame(w, IOUtils.writer(w));
+ }
+
+ @Test
+ public void testAsWriterAppendable() {
+ final Appendable a = new StringBuffer();
+ final Writer w = IOUtils.writer(a);
+ assertNotSame(w, a);
+ assertEquals(AppendableWriter.class, w.getClass());
+ assertSame(w, IOUtils.writer(w));
+ }
@Test
public void testCopyLarge_SkipWithInvalidOffset() throws IOException {
diff --git a/src/test/java/org/apache/commons/io/output/AppendableWriterTest.java b/src/test/java/org/apache/commons/io/output/AppendableWriterTest.java
new file mode 100644
index 0000000..f99f8c9
--- /dev/null
+++ b/src/test/java/org/apache/commons/io/output/AppendableWriterTest.java
@@ -0,0 +1,88 @@
+/*
+ * 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.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Unit tests for {@link AppendableWriter}.
+ *
+ */
+public class AppendableWriterTest {
+
+ private AppendableWriter<StringBuilder> out;
+
+ @Before
+ public void setUp() throws Exception {
+ out = new AppendableWriter<>(new StringBuilder());
+ }
+
+ @Test
+ public void testWriteInt() throws Exception {
+ out.write('F');
+
+ assertEquals("F", out.getAppendable().toString());
+ }
+
+ @Test
+ public void testWriteChars() throws Exception {
+ final String testData = "ABCD";
+
+ out.write(testData.toCharArray());
+
+ assertEquals(testData, out.getAppendable().toString());
+ }
+
+ @Test
+ public void testWriteString() throws Exception {
+ final String testData = "ABCD";
+
+ out.write(testData);
+
+ assertEquals(testData, out.getAppendable().toString());
+ }
+
+ @Test
+ public void testAppendCharSequence() throws Exception {
+ final String testData = "ABCD";
+
+ out.append(testData);
+ out.append(null);
+
+ assertEquals(testData + "null", out.getAppendable().toString());
+ }
+
+ @Test
+ public void testAppendSubSequence() throws Exception {
+ final String testData = "ABCD";
+
+ out.append(testData, 1, 3);
+ out.append(null, 1, 3);
+
+ assertEquals(testData.substring(1, 3) + "ul", out.getAppendable().toString());
+ }
+
+ @Test
+ public void testAppendChar() throws Exception {
+ out.append('F');
+
+ assertEquals("F", out.getAppendable().toString());
+ }
+}