8183554: Add constructors with Charset parameter for FileReader and FileWriter
Reviewed-by: alanb, rriggs, smarks
--- a/src/java.base/share/classes/java/io/FileReader.java Thu Mar 15 19:33:04 2018 +0100
+++ b/src/java.base/share/classes/java/io/FileReader.java Thu Mar 15 14:54:10 2018 -0700
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1996, 2001, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -25,16 +25,17 @@
package java.io;
+import java.nio.charset.Charset;
/**
- * Convenience class for reading character files. The constructors of this
- * class assume that the default character encoding and the default byte-buffer
- * size are appropriate. To specify these values yourself, construct an
- * InputStreamReader on a FileInputStream.
+ * Reads text from character files using a default buffer size. Decoding from bytes
+ * to characters uses either a specified {@linkplain java.nio.charset.Charset charset}
+ * or the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * <p>{@code FileReader} is meant for reading streams of characters.
- * For reading streams of raw bytes, consider using a
- * {@code FileInputStream}.
+ * <p>
+ * The {@code FileReader} is meant for reading streams of characters. For reading
+ * streams of raw bytes, consider using a {@code FileInputStream}.
*
* @see InputStreamReader
* @see FileInputStream
@@ -45,10 +46,11 @@
public class FileReader extends InputStreamReader {
/**
- * Creates a new {@code FileReader}, given the name of the
- * file to read from.
+ * Creates a new {@code FileReader}, given the name of the file to read,
+ * using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * @param fileName the name of the file to read from
+ * @param fileName the name of the file to read
* @exception FileNotFoundException if the named file does not exist,
* is a directory rather than a regular file,
* or for some other reason cannot be opened for
@@ -59,10 +61,11 @@
}
/**
- * Creates a new {@code FileReader}, given the {@code File}
- * to read from.
+ * Creates a new {@code FileReader}, given the {@code File} to read,
+ * using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * @param file the {@code File} to read from
+ * @param file the {@code File} to read
* @exception FileNotFoundException if the file does not exist,
* is a directory rather than a regular file,
* or for some other reason cannot be opened for
@@ -73,13 +76,47 @@
}
/**
- * Creates a new {@code FileReader}, given the
- * {@code FileDescriptor} to read from.
+ * Creates a new {@code FileReader}, given the {@code FileDescriptor} to read,
+ * using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * @param fd the FileDescriptor to read from
+ * @param fd the {@code FileDescriptor} to read
*/
public FileReader(FileDescriptor fd) {
super(new FileInputStream(fd));
}
+ /**
+ * Creates a new {@code FileReader}, given the name of the file to read
+ * and the {@linkplain java.nio.charset.Charset charset}.
+ *
+ * @param fileName the name of the file to read
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @exception IOException if the named file does not exist,
+ * is a directory rather than a regular file,
+ * or for some other reason cannot be opened for
+ * reading.
+ *
+ * @since 11
+ */
+ public FileReader(String fileName, Charset charset) throws IOException {
+ super(new FileInputStream(fileName), charset);
+ }
+
+ /**
+ * Creates a new {@code FileReader}, given the {@code File} to read and
+ * the {@linkplain java.nio.charset.Charset charset}.
+ *
+ * @param file the {@code File} to read
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @exception IOException if the file does not exist,
+ * is a directory rather than a regular file,
+ * or for some other reason cannot be opened for
+ * reading.
+ *
+ * @since 11
+ */
+ public FileReader(File file, Charset charset) throws IOException {
+ super(new FileInputStream(file), charset);
+ }
}
--- a/src/java.base/share/classes/java/io/FileWriter.java Thu Mar 15 19:33:04 2018 +0100
+++ b/src/java.base/share/classes/java/io/FileWriter.java Thu Mar 15 14:54:10 2018 -0700
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1996, 2001, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -25,22 +25,24 @@
package java.io;
+import java.nio.charset.Charset;
/**
- * Convenience class for writing character files. The constructors of this
- * class assume that the default character encoding and the default byte-buffer
- * size are acceptable. To specify these values yourself, construct an
- * OutputStreamWriter on a FileOutputStream.
+ * Writes text to character files using a default buffer size. Encoding from characters
+ * to bytes uses either a specified {@linkplain java.nio.charset.Charset charset}
+ * or the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * <p>Whether or not a file is available or may be created depends upon the
+ * <p>
+ * Whether or not a file is available or may be created depends upon the
* underlying platform. Some platforms, in particular, allow a file to be
* opened for writing by only one {@code FileWriter} (or other file-writing
* object) at a time. In such situations the constructors in this class
* will fail if the file involved is already open.
*
- * <p>{@code FileWriter} is meant for writing streams of characters.
- * For writing streams of raw bytes, consider using a
- * {@code FileOutputStream}.
+ * <p>
+ * The {@code FileWriter} is meant for writing streams of characters. For writing
+ * streams of raw bytes, consider using a {@code FileOutputStream}.
*
* @see OutputStreamWriter
* @see FileOutputStream
@@ -52,7 +54,8 @@
public class FileWriter extends OutputStreamWriter {
/**
- * Constructs a FileWriter object given a file name.
+ * Constructs a {@code FileWriter} given a file name, using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}
*
* @param fileName String The system-dependent filename.
* @throws IOException if the named file exists but is a directory rather
@@ -64,8 +67,9 @@
}
/**
- * Constructs a FileWriter object given a file name with a boolean
- * indicating whether or not to append the data written.
+ * Constructs a {@code FileWriter} given a file name and a boolean indicating
+ * whether to append the data written, using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
* @param fileName String The system-dependent filename.
* @param append boolean if {@code true}, then data will be written
@@ -79,9 +83,11 @@
}
/**
- * Constructs a FileWriter object given a File object.
+ * Constructs a {@code FileWriter} given the {@code File} to write,
+ * using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}
*
- * @param file a File object to write to.
+ * @param file the {@code File} to write.
* @throws IOException if the file exists but is a directory rather than
* a regular file, does not exist but cannot be created,
* or cannot be opened for any other reason
@@ -91,11 +97,11 @@
}
/**
- * Constructs a FileWriter object given a File object. If the second
- * argument is {@code true}, then bytes will be written to the end
- * of the file rather than the beginning.
+ * Constructs a {@code FileWriter} given the {@code File} to write and
+ * a boolean indicating whether to append the data written, using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * @param file a File object to write to
+ * @param file the {@code File} to write
* @param append if {@code true}, then bytes will be written
* to the end of the file rather than the beginning
* @throws IOException if the file exists but is a directory rather than
@@ -108,12 +114,83 @@
}
/**
- * Constructs a FileWriter object associated with a file descriptor.
+ * Constructs a {@code FileWriter} given a file descriptor,
+ * using the platform's
+ * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
*
- * @param fd FileDescriptor object to write to.
+ * @param fd the {@code FileDescriptor} to write.
*/
public FileWriter(FileDescriptor fd) {
super(new FileOutputStream(fd));
}
+
+ /**
+ * Constructs a {@code FileWriter} given a file name and
+ * {@linkplain java.nio.charset.Charset charset}.
+ *
+ * @param fileName the name of the file to write
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @throws IOException if the named file exists but is a directory rather
+ * than a regular file, does not exist but cannot be
+ * created, or cannot be opened for any other reason
+ *
+ * @since 11
+ */
+ public FileWriter(String fileName, Charset charset) throws IOException {
+ super(new FileOutputStream(fileName), charset);
+ }
+
+ /**
+ * Constructs a {@code FileWriter} given a file name,
+ * {@linkplain java.nio.charset.Charset charset} and a boolean indicating
+ * whether to append the data written.
+ *
+ * @param fileName the name of the file to write
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @param append a boolean. If {@code true}, the writer will write the data
+ * to the end of the file rather than the beginning.
+ * @throws IOException if the named file exists but is a directory rather
+ * than a regular file, does not exist but cannot be
+ * created, or cannot be opened for any other reason
+ *
+ * @since 11
+ */
+ public FileWriter(String fileName, Charset charset, boolean append) throws IOException {
+ super(new FileOutputStream(fileName, append), charset);
+ }
+
+ /**
+ * Constructs a {@code FileWriter} given the {@code File} to write and
+ * {@linkplain java.nio.charset.Charset charset}.
+ *
+ * @param file the {@code File} to write
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @throws IOException if the file exists but is a directory rather than
+ * a regular file, does not exist but cannot be created,
+ * or cannot be opened for any other reason
+ *
+ * @since 11
+ */
+ public FileWriter(File file, Charset charset) throws IOException {
+ super(new FileOutputStream(file), charset);
+ }
+
+ /**
+ * Constructs a {@code FileWriter} given the {@code File} to write,
+ * {@linkplain java.nio.charset.Charset charset} and a boolean indicating
+ * whether to append the data written.
+ *
+ * @param file the {@code File} to write
+ * @param charset the {@linkplain java.nio.charset.Charset charset}
+ * @param append a boolean. If {@code true}, the writer will write the data
+ * to the end of the file rather than the beginning.
+ * @throws IOException if the file exists but is a directory rather than
+ * a regular file, does not exist but cannot be created,
+ * or cannot be opened for any other reason
+ * @since 11
+ */
+ public FileWriter(File file, Charset charset, boolean append) throws IOException {
+ super(new FileOutputStream(file, append), charset);
+ }
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/io/FileReader/ConstructorTest.java Thu Mar 15 14:54:10 2018 -0700
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.testng.Assert;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+/**
+ * @test
+ * @bug 8183554
+ * @summary Test to verify the new Constructors that take a Charset.
+ * @run testng ConstructorTest
+ */
+public class ConstructorTest {
+ static String USER_DIR = System.getProperty("user.dir", ".");
+
+ public static enum ConstructorType {
+ STRING,
+ FILE
+ }
+
+ static final String TEST_STRING = "abc \u0100 \u0101 \u0555 \u07FD \u07FF";
+ static final int BUFFER_SIZE = 8192;
+
+ @DataProvider(name = "parameters")
+ public Object[][] getParameters() throws IOException {
+ File file1 = new File(USER_DIR, "FileReaderTest1.txt");
+ File file2 = new File(USER_DIR, "FileReaderTest2.txt");
+
+ return new Object[][]{
+ {ConstructorType.STRING, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.FILE, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.STRING, file1, file2, StandardCharsets.ISO_8859_1},
+ {ConstructorType.FILE, file1, file2, StandardCharsets.ISO_8859_1},
+ };
+ }
+
+ /**
+ * Verifies that the new constructors that take a Charset function the same
+ * as an InputStreamReader on a FileInputStream as was recommended before
+ * this change.
+ *
+ * @param type the type of the constructor
+ * @param file1 file1 to be read with a FileReader
+ * @param file2 file2 to be read with an InputStreamReader
+ * @param charset the charset
+ * @throws IOException
+ */
+ @Test(dataProvider = "parameters")
+ void test(ConstructorType type, File file1, File file2, Charset charset)
+ throws Exception {
+ prepareFile(file1, TEST_STRING, charset);
+ prepareFile(file2, TEST_STRING, charset);
+
+ try (FileReader fr = getFileReader(type, file1, charset);
+ FileInputStream is = new FileInputStream(file2);
+ InputStreamReader isr = new InputStreamReader(is, charset);) {
+ String result1 = readAll(fr, BUFFER_SIZE);
+ String result2 = readAll(isr, BUFFER_SIZE);
+ Assert.assertEquals(result1, result2);
+ }
+ }
+
+ public String readAll(Reader reader, int bufferSize) throws IOException {
+ StringBuilder sb = new StringBuilder();
+ char[] buf = new char[bufferSize];
+ int numRead;
+ while ((numRead = reader.read(buf)) != -1) {
+ if (numRead == buf.length) {
+ sb.append(buf);
+ } else {
+ sb.append(String.valueOf(buf, 0, numRead));
+ }
+ }
+ return sb.toString();
+ }
+
+ /*
+ * Creates a FileReader over the given input file.
+ */
+ FileReader getFileReader(ConstructorType type, File file, Charset charset)
+ throws IOException {
+ switch (type) {
+ case STRING:
+ return new FileReader(file.getPath(), charset);
+ case FILE:
+ return new FileReader(file, charset);
+ }
+
+ return null;
+ }
+
+ void prepareFile(File file, String content, Charset charset) throws IOException {
+ try (FileWriter writer = new FileWriter(file, charset);) {
+ writer.write(content);
+ }
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/io/FileWriter/ConstructorTest.java Thu Mar 15 14:54:10 2018 -0700
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Reader;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.testng.Assert;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+/**
+ * @test
+ * @bug 8183554
+ * @summary Test to verify the new Constructors that take a Charset.
+ * @run testng ConstructorTest
+ */
+public class ConstructorTest {
+ static String USER_DIR = System.getProperty("user.dir", ".");
+
+ public static enum ConstructorType {
+ STRING,
+ FILE,
+ STRING_APPEND,
+ FILE_APPEND
+ }
+
+ static final String TEST_STRING = "abc \u0100 \u0101 \u0555 \u07FD \u07FF";
+ static final int BUFFER_SIZE = 8192;
+
+ @DataProvider(name = "parameters")
+ public Object[][] getParameters() throws IOException {
+ File file1 = new File(USER_DIR, "FileWriterTest1.txt");
+ File file2 = new File(USER_DIR, "FileWriterTest2.txt");
+
+ return new Object[][]{
+ {ConstructorType.STRING, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.FILE, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.STRING_APPEND, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.FILE_APPEND, file1, file2, StandardCharsets.UTF_8},
+ {ConstructorType.STRING, file1, file2, StandardCharsets.ISO_8859_1},
+ {ConstructorType.FILE, file1, file2, StandardCharsets.ISO_8859_1},
+ {ConstructorType.STRING_APPEND, file1, file2, StandardCharsets.ISO_8859_1},
+ {ConstructorType.FILE_APPEND, file1, file2, StandardCharsets.ISO_8859_1},
+ };
+ }
+
+ /**
+ * Verifies that the new constructors that take a Charset function the same
+ * as an OutputStreamWriter on a FileOutputStream as was recommended before
+ * this change.
+ *
+ * @param type the type of the constructor
+ * @param file1 file1 to be written with a FileWriter
+ * @param file2 file2 to be written with an OutputStreamWriter
+ * @param charset the charset
+ * @throws IOException
+ */
+ @Test(dataProvider = "parameters")
+ void test(ConstructorType type, File file1, File file2, Charset charset)
+ throws Exception {
+ writeWithFileWriter(type, file1, TEST_STRING, charset);
+ writeWithOutputStreamWriter(type, file2, TEST_STRING, charset);
+
+ try (
+ FileReader r1 = getFileReader(type, file1, charset);
+ FileReader r2 = getFileReader(type, file2, charset);
+ ) {
+ String result1 = readAll(r1, BUFFER_SIZE);
+ String result2 = readAll(r2, BUFFER_SIZE);
+ Assert.assertEquals(result1, result2);
+ }
+ }
+
+ public String readAll(Reader reader, int bufferSize) throws IOException {
+ StringBuilder sb = new StringBuilder();
+ char[] buf = new char[bufferSize];
+ int numRead;
+ while ((numRead = reader.read(buf)) != -1) {
+ if (numRead == buf.length) {
+ sb.append(buf);
+ } else {
+ sb.append(String.valueOf(buf, 0, numRead));
+ }
+ }
+ return sb.toString();
+ }
+
+ /*
+ * Creates a FileReader over the given input file.
+ */
+ FileReader getFileReader(ConstructorType type, File file, Charset charset)
+ throws IOException {
+ switch (type) {
+ case STRING:
+ case STRING_APPEND:
+ return new FileReader(file.getPath(), charset);
+ case FILE:
+ case FILE_APPEND:
+ return new FileReader(file, charset);
+ }
+
+ return null;
+ }
+
+ /*
+ * Creates a FileWriter using the constructor as specified.
+ */
+ FileWriter getFileWriter(ConstructorType type, File file, Charset charset)
+ throws IOException {
+ switch (type) {
+ case STRING:
+ return new FileWriter(file.getPath(), charset);
+ case FILE:
+ return new FileWriter(file, charset);
+ case STRING_APPEND:
+ return new FileWriter(file.getPath(), charset, true);
+ case FILE_APPEND:
+ return new FileWriter(file, charset, true);
+ }
+
+ return null;
+ }
+
+ void writeWithFileWriter(ConstructorType type, File file, String content, Charset charset)
+ throws IOException {
+ if (type == ConstructorType.STRING_APPEND || type == ConstructorType.FILE_APPEND) {
+ try (FileWriter writer = getFileWriter(ConstructorType.FILE, file, charset);) {
+ writer.write(content);
+ }
+ }
+ try (FileWriter writer = getFileWriter(type, file, charset);) {
+ writer.write(content);
+ }
+ }
+
+ void writeWithOutputStreamWriter(ConstructorType type, File file, String content, Charset charset)
+ throws IOException {
+ try (OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file), charset)) {
+ writer.write(content);
+ if (type == ConstructorType.STRING_APPEND || type == ConstructorType.FILE_APPEND) {
+ writer.write(content);
+ }
+ }
+ }
+}