mirror of
https://github.com/openjdk/jdk.git
synced 2025-08-26 22:34:27 +02:00
8201276: (fs) Add methods to Files for reading/writing a string from/to a file
Reviewed-by: rriggs, smarks, sherman, forax, alanb, mli
This commit is contained in:
Joe Wang
parent
b5eadc5721
commit
ca487166f4
5 changed files with 635 additions and 3 deletions
|
|
@ -3121,6 +3121,9 @@ public final class Files {
|
|||
*/
|
||||
private static final int MAX_BUFFER_SIZE = Integer.MAX_VALUE - 8;
|
||||
|
||||
private static final jdk.internal.misc.JavaLangAccess JLA =
|
||||
jdk.internal.misc.SharedSecrets.getJavaLangAccess();
|
||||
|
||||
/**
|
||||
* Reads all the bytes from an input stream. Uses {@code initialSize} as a hint
|
||||
* about how many bytes the stream will have.
|
||||
|
|
@ -3202,6 +3205,81 @@ public final class Files {
|
|||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads all content from a file into a string, decoding from bytes to characters
|
||||
* using the {@link StandardCharsets#UTF_8 UTF-8} {@link Charset charset}.
|
||||
* The method ensures that the file is closed when all content have been read
|
||||
* or an I/O error, or other runtime exception, is thrown.
|
||||
*
|
||||
* <p> This method is equivalent to:
|
||||
* {@code readString(path, StandardCharsets.UTF_8) }
|
||||
*
|
||||
* @param path the path to the file
|
||||
*
|
||||
* @return a String containing the content read from the file
|
||||
*
|
||||
* @throws IOException
|
||||
* if an I/O error occurs reading from the file or a malformed or
|
||||
* unmappable byte sequence is read
|
||||
* @throws OutOfMemoryError
|
||||
* if the file is extremely large, for example larger than {@code 2GB}
|
||||
* @throws SecurityException
|
||||
* In the case of the default provider, and a security manager is
|
||||
* installed, the {@link SecurityManager#checkRead(String) checkRead}
|
||||
* method is invoked to check read access to the file.
|
||||
*
|
||||
* @since 11
|
||||
*/
|
||||
public static String readString(Path path) throws IOException {
|
||||
return readString(path, StandardCharsets.UTF_8);
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads all characters from a file into a string, decoding from bytes to characters
|
||||
* using the specified {@linkplain Charset charset}.
|
||||
* The method ensures that the file is closed when all content have been read
|
||||
* or an I/O error, or other runtime exception, is thrown.
|
||||
*
|
||||
* <p> This method reads all content including the line separators in the middle
|
||||
* and/or at the end. The resulting string will contain line separators as they
|
||||
* appear in the file.
|
||||
*
|
||||
* @apiNote
|
||||
* This method is intended for simple cases where it is appropriate and convenient
|
||||
* to read the content of a file into a String. It is not intended for reading
|
||||
* very large files.
|
||||
*
|
||||
*
|
||||
*
|
||||
* @param path the path to the file
|
||||
* @param cs the charset to use for decoding
|
||||
*
|
||||
* @return a String containing the content read from the file
|
||||
*
|
||||
* @throws IOException
|
||||
* if an I/O error occurs reading from the file or a malformed or
|
||||
* unmappable byte sequence is read
|
||||
* @throws OutOfMemoryError
|
||||
* if the file is extremely large, for example larger than {@code 2GB}
|
||||
* @throws SecurityException
|
||||
* In the case of the default provider, and a security manager is
|
||||
* installed, the {@link SecurityManager#checkRead(String) checkRead}
|
||||
* method is invoked to check read access to the file.
|
||||
*
|
||||
* @since 11
|
||||
*/
|
||||
public static String readString(Path path, Charset cs) throws IOException {
|
||||
Objects.requireNonNull(path);
|
||||
Objects.requireNonNull(cs);
|
||||
|
||||
byte[] ba = readAllBytes(path);
|
||||
try {
|
||||
return JLA.newStringNoRepl(ba, cs);
|
||||
} catch (IllegalArgumentException e) {
|
||||
throw new IOException(e);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Read all lines from a file. This method ensures that the file is
|
||||
* closed when all bytes have been read or an I/O error, or other runtime
|
||||
|
|
@ -3456,6 +3534,110 @@ public final class Files {
|
|||
return write(path, lines, StandardCharsets.UTF_8, options);
|
||||
}
|
||||
|
||||
/**
|
||||
* Write a {@linkplain java.lang.CharSequence CharSequence} to a file.
|
||||
* Characters are encoded into bytes using the
|
||||
* {@link StandardCharsets#UTF_8 UTF-8} {@link Charset charset}.
|
||||
*
|
||||
* <p> This method is equivalent to:
|
||||
* {@code writeString(path, test, StandardCharsets.UTF_8, options) }
|
||||
*
|
||||
* @param path
|
||||
* the path to the file
|
||||
* @param csq
|
||||
* the CharSequence to be written
|
||||
* @param options
|
||||
* options specifying how the file is opened
|
||||
*
|
||||
* @return the path
|
||||
*
|
||||
* @throws IllegalArgumentException
|
||||
* if {@code options} contains an invalid combination of options
|
||||
* @throws IOException
|
||||
* if an I/O error occurs writing to or creating the file, or the
|
||||
* text cannot be encoded using the specified charset
|
||||
* @throws UnsupportedOperationException
|
||||
* if an unsupported option is specified
|
||||
* @throws SecurityException
|
||||
* In the case of the default provider, and a security manager is
|
||||
* installed, the {@link SecurityManager#checkWrite(String) checkWrite}
|
||||
* method is invoked to check write access to the file. The {@link
|
||||
* SecurityManager#checkDelete(String) checkDelete} method is
|
||||
* invoked to check delete access if the file is opened with the
|
||||
* {@code DELETE_ON_CLOSE} option.
|
||||
*
|
||||
* @since 11
|
||||
*/
|
||||
public static Path writeString(Path path, CharSequence csq, OpenOption... options)
|
||||
throws IOException
|
||||
{
|
||||
return writeString(path, csq, StandardCharsets.UTF_8, options);
|
||||
}
|
||||
|
||||
/**
|
||||
* Write a {@linkplain java.lang.CharSequence CharSequence} to a file.
|
||||
* Characters are encoded into bytes using the specified
|
||||
* {@linkplain java.nio.charset.Charset charset}.
|
||||
*
|
||||
* <p> All characters are written as they are, including the line separators in
|
||||
* the char sequence. No extra characters are added.
|
||||
*
|
||||
* <p> The {@code options} parameter specifies how the file is created
|
||||
* or opened. If no options are present then this method works as if the
|
||||
* {@link StandardOpenOption#CREATE CREATE}, {@link
|
||||
* StandardOpenOption#TRUNCATE_EXISTING TRUNCATE_EXISTING}, and {@link
|
||||
* StandardOpenOption#WRITE WRITE} options are present. In other words, it
|
||||
* opens the file for writing, creating the file if it doesn't exist, or
|
||||
* initially truncating an existing {@link #isRegularFile regular-file} to
|
||||
* a size of {@code 0}.
|
||||
*
|
||||
*
|
||||
* @param path
|
||||
* the path to the file
|
||||
* @param csq
|
||||
* the CharSequence to be written
|
||||
* @param cs
|
||||
* the charset to use for encoding
|
||||
* @param options
|
||||
* options specifying how the file is opened
|
||||
*
|
||||
* @return the path
|
||||
*
|
||||
* @throws IllegalArgumentException
|
||||
* if {@code options} contains an invalid combination of options
|
||||
* @throws IOException
|
||||
* if an I/O error occurs writing to or creating the file, or the
|
||||
* text cannot be encoded using the specified charset
|
||||
* @throws UnsupportedOperationException
|
||||
* if an unsupported option is specified
|
||||
* @throws SecurityException
|
||||
* In the case of the default provider, and a security manager is
|
||||
* installed, the {@link SecurityManager#checkWrite(String) checkWrite}
|
||||
* method is invoked to check write access to the file. The {@link
|
||||
* SecurityManager#checkDelete(String) checkDelete} method is
|
||||
* invoked to check delete access if the file is opened with the
|
||||
* {@code DELETE_ON_CLOSE} option.
|
||||
*
|
||||
* @since 11
|
||||
*/
|
||||
public static Path writeString(Path path, CharSequence csq, Charset cs, OpenOption... options)
|
||||
throws IOException
|
||||
{
|
||||
// ensure the text is not null before opening file
|
||||
Objects.requireNonNull(path);
|
||||
Objects.requireNonNull(csq);
|
||||
Objects.requireNonNull(cs);
|
||||
|
||||
try {
|
||||
byte[] bytes = JLA.getBytesNoRepl(String.valueOf(csq), cs);
|
||||
write(path, bytes, options);
|
||||
} catch (IllegalArgumentException e) {
|
||||
throw new IOException(e);
|
||||
}
|
||||
|
||||
return path;
|
||||
}
|
||||
|
||||
// -- Stream APIs --
|
||||
|
||||
/**
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue