com.chemaxon.calculations.util

Class CmdlineUtils

java.lang.Object

com.chemaxon.calculations.util.CmdlineUtils

@PublicAPI
 @Beta
public final class CmdlineUtils
extends Object

Command line related utilities. IO is accessed through a CmdlineContext acquired with ServiceLoader. A single service registration is expected.

Please note that this class is marked with @Beta annotation, so it can be subject of incompatible changes or removal in later releases.

Field Summary

Fields

Modifier and Type	Field and Description
static String	UTF8ENCODING UTF-8 encoding String literal.

Method Summary

Modifier and Type	Method and Description
static InputStream	autoGzip(InputStream in) Detect gzipped InputStream.
static void	exit(int status) Terminate execution with given status code.
static PrintStream	getErr() Get stderr to use.
static InputStream	getIn() Get stdin to use.
static PrintStream	getOut() Get stdout to use.
static InputStream	inputStreamFromLocation(String location) Create InputStream from not nullable location.
static InputStream	inputStreamFromLocation(String location, boolean autoGzip) Create InputStream from not nullable location.
static Optional<InputStream>	inputStreamFromNullableLocation(String location) Create in input stream from nullable location.
static Optional<InputStream>	inputStreamFromNullableLocation(String location, boolean autoGzip) Create in input stream from nullable location.
static boolean	isFileExists(String name) Check if a file exists.
static CloseableLineIterator	lineIteratorFromLocation(String location) Create a LineIterator from a not nullable location.
static CloseableLineIterator	lineIteratorFromLocation(String location, boolean autoGzip) Create a LineIterator from a not nullable location.
static ObjectInputStream	objectInputStreamFromLocation(String location) Create ObjectInputStream from a not nullable location.
static ObjectInputStream	objectInputStreamFromLocation(String location, boolean autoGzip) Create ObjectInputStream from a not nullable location.
static Optional<ObjectInputStream>	objectInputStreamFromNullableLocation(String location) Create in object input stream from nullable location.
static ObjectOutputStream	objectOutputStreamFromLocation(String location) ObjectOutputStream from a location.
static Optional<ObjectOutputStream>	objectOutputStreamFromNullableLocation(String location) ObjectOutputStream from a nullable location.
static InputStream	openUrlStream(String spec) Open an URL connection.
static OutputStream	outputStreamFromLocation(String location) OutputStream from a location.
static PrintStream	printStreamFromLocation(String location) PrintStream from a location.
static Optional<PrintStream>	printStreamFromNullableLocation(String location) PrintStream from a nullable location.
static String	stringFromLocation(String location) Read the contents of a location into a String.
static String	stringFromLocation(String location, boolean autoGzip) Read the contents of a location into a String.
static Optional<String>	stringFromNullableLocation(String location) Read the contents of a location when it is not null.
static Optional<String>	stringFromNullableLocation(String location, boolean autoGzip) Read the contents of a location when it is not null.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

UTF8ENCODING

public static final String UTF8ENCODING

UTF-8 encoding String literal.

See Also:

Constant Field Values

Method Detail

autoGzip

public static InputStream autoGzip(InputStream in)
                            throws IOException

Detect gzipped InputStream. Checks GZIPInputStream.GZIP_MAGIC and wraps input when match found. Further validity check is not done. See http://stackoverflow.com/questions/1080381/gzipinputstream-reading-line-by-line.

Parameters:

in - Input

Returns:

Input wrapped in GZIPInputStream when GZIPInputStream.GZIP_MAGIC match, otherwise input, possibly wrapped in a BufferedInputStream.

Throws:

IOException - Propagated

getOut

public static PrintStream getOut()

Get stdout to use.

Returns:

StdOut specified by the default command line context

getErr

public static PrintStream getErr()

Get stderr to use.

Returns:

StdErr specified by the default command line context

getIn

public static InputStream getIn()

Get stdin to use.

Returns:

StdIn specified by the default command line context

isFileExists

public static boolean isFileExists(String name)

Check if a file exists.

Parameters:

name - Name to delegate

openUrlStream

public static InputStream openUrlStream(String spec)
                                 throws IOException

Open an URL connection.

Parameters:

spec - URL spec

Returns:

Stream

Throws:

IOException - Propagated

exit

public static void exit(int status)
                 throws CmdlineContext.ExitWithNonZeroStatus,
                        CmdlineContext.ExitWithZeroStatus

Terminate execution with given status code. By default implementation calls System.exit(int). Test time implementations might decide to throw ExitWithZeroStatus or ExitWithNonZeroStatus instead of delegating to System.exit(int). These RuntimeExceptions are helps for test implementations, regular application code must not catch them.

Parameters:

status - Status code; by convention nonzero status code indicates abnormal termination

Throws:

CmdlineContext.ExitWithZeroStatus - Test time implementation might throw this instead of delegating to System.exit(int) Note that normal application code must not catch this.

CmdlineContext.ExitWithNonZeroStatus - Test time implementation might throw this instead of delegating to System.exit(int) Note that normal application code must not catch this.

inputStreamFromLocation

public static InputStream inputStreamFromLocation(String location)
                                           throws FileNotFoundException

Create InputStream from not nullable location.

Parameters:

location - File name or "-" for stdin.

Returns:

Input stream representing given location. Returned input stream should be closed after usage. If stdin requested it is wrapped in a CloseShieldInputStream

Throws:

FileNotFoundException - thrown by FileInputStream.FileInputStream(java.lang.String)

inputStreamFromLocation

public static InputStream inputStreamFromLocation(String location,
                                                  boolean autoGzip)
                                           throws IOException

Create InputStream from not nullable location.

Parameters:

location - File name or "-" for stdin.

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

Input stream representing given location. Returned input stream should be closed after usage. If stdin requested it is wrapped in a CloseShieldInputStream

Throws:

IOException - propagated

objectInputStreamFromLocation

public static ObjectInputStream objectInputStreamFromLocation(String location,
                                                              boolean autoGzip)
                                                       throws IOException

Create ObjectInputStream from a not nullable location.

Parameters:

location - File name or "-" for stdin

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

ObjectInputStream to be used

Throws:

IOException - re-thrown

objectInputStreamFromLocation

public static ObjectInputStream objectInputStreamFromLocation(String location)
                                                       throws IOException

Create ObjectInputStream from a not nullable location.

Parameters:

location - File name or "-" for stdin

Returns:

ObjectInputStream to be used

Throws:

IOException - re-thrown

lineIteratorFromLocation

public static CloseableLineIterator lineIteratorFromLocation(String location,
                                                             boolean autoGzip)
                                                      throws IOException

Create a LineIterator from a not nullable location.

Note that the returned instance must be closed by calling LineIterator.close() or LineIterator.closeQuietly(org.apache.commons.io.LineIterator), preferably in a finally block

Parameters:

location - File name or "-" for stdin

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

LineIterator for the given location

Throws:

IOException - re-thrown

lineIteratorFromLocation

public static CloseableLineIterator lineIteratorFromLocation(String location)
                                                      throws IOException

Create a LineIterator from a not nullable location.

Note that the returned instance must be closed by calling LineIterator.close() or LineIterator.closeQuietly(org.apache.commons.io.LineIterator), preferably in a finally block

Parameters:

location - File name or "-" for stdin

Returns:

LineIterator for the given location

Throws:

IOException - re-thrown

inputStreamFromNullableLocation

public static Optional<InputStream> inputStreamFromNullableLocation(String location,
                                                                    boolean autoGzip)
                                                             throws IOException

Create in input stream from nullable location.

The returned InputStream should be closed in a proper finally block by invoking its InputStream.close() method. If stdin used then a CloseShieldInputStream is returned which is safe to close.

Parameters:

location - File name or "-" for stdin

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

Input stream representing given location

Throws:

IOException - thrown by FileInputStream.FileInputStream(java.lang.String) or by autoGzip(java.io.InputStream).

inputStreamFromNullableLocation

public static Optional<InputStream> inputStreamFromNullableLocation(String location)
                                                             throws IOException

Create in input stream from nullable location.

The returned InputStream should be closed in a proper finally block by invoking its InputStream.close() method. If stdin used then a CloseShieldInputStream is returned which is safe to close.

Parameters:

location - File name or "-" for stdin

Returns:

Input stream representing given location

Throws:

IOException - thrown by FileInputStream.FileInputStream(java.lang.String) or by autoGzip(java.io.InputStream).

objectInputStreamFromNullableLocation

public static Optional<ObjectInputStream> objectInputStreamFromNullableLocation(String location)
                                                                         throws IOException

Create in object input stream from nullable location.

The returned Object should be closed in a proper finally block by invoking its ObjectInputStream.close() method. If stdin used then a CloseShieldInputStream is used which is safe to close.

Parameters:

location - File name or "-" for stdin

Returns:

ObjectInputStream representing given location

Throws:

IOException - re-thrown

outputStreamFromLocation

public static OutputStream outputStreamFromLocation(String location)
                                             throws FileNotFoundException

OutputStream from a location.

Parameters:

location - File name or "-" for stdout, "-2" for stderr. Location "/dev/null" is considered as a NullOutputStream. Note that NullOutputStream is available both in apache commons io and in Guava, however Guava version is marked with Beta, so apache version is used.

Returns:

OutputStream for given location which is safe and should be closed explicitly

Throws:

FileNotFoundException - thrown by FileOutputStream.FileOutputStream(java.lang.String)

printStreamFromLocation

public static PrintStream printStreamFromLocation(String location)
                                           throws FileNotFoundException

PrintStream from a location.

Parameters:

location - File name or "-" for stdout, "-2" for stderr. Location "/dev/null" is considered as a NullOutputStream. Note that NullOutputStream is available both in apache commons io and in Guava, however Guava version is marked with Beta, so apache version is used.

Returns:

UTF-8 encoded PrintStream for given location which is safe and should be closed explicitly

Throws:

FileNotFoundException - thrown by FileOutputStream.FileOutputStream(java.lang.String)

objectOutputStreamFromLocation

public static ObjectOutputStream objectOutputStreamFromLocation(String location)
                                                         throws IOException

ObjectOutputStream from a location.

Parameters:

location - File name or "-" for stdout, "-2" for stderr. Location "/dev/null" is considered as a NullOutputStream. Note that NullOutputStream is available both in apache commons io and in Guava, however Guava version is marked with Beta, so apache version is used.

Returns:

ObjectOutputStream for given location which is safe and should be closed explicitly

Throws:

IOException - thrown by underlying streams

stringFromLocation

public static String stringFromLocation(String location,
                                        boolean autoGzip)
                                 throws IllegalArgumentException

Read the contents of a location into a String.

Parameters:

location - Location passed to inputStreamFromLocation(java.lang.String)

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

Contents read by IOUtils.toString(java.io.InputStream, java.lang.String)

Throws:

IllegalArgumentException - When something goes wrong

stringFromLocation

public static String stringFromLocation(String location)
                                 throws IllegalArgumentException

Read the contents of a location into a String.

Parameters:

location - Location passed to inputStreamFromLocation(java.lang.String)

Returns:

Contents read by IOUtils.toString(java.io.InputStream, java.lang.String)

Throws:

IllegalArgumentException - When something goes wrong

printStreamFromNullableLocation

public static Optional<PrintStream> printStreamFromNullableLocation(String location)
                                                             throws FileNotFoundException

PrintStream from a nullable location.

Parameters:

location - File name or "-" for stdout, "-2" for stderr

Returns:

UTF-8 encoded PrintStream for given location which is safe and should be closed explicitly when not null given

Throws:

FileNotFoundException - thrown by FileOutputStream.FileOutputStream(java.lang.String)

objectOutputStreamFromNullableLocation

public static Optional<ObjectOutputStream> objectOutputStreamFromNullableLocation(String location)
                                                                           throws IOException

ObjectOutputStream from a nullable location.

Parameters:

location - File name or "-" for stdout, "-2" for stderr

Returns:

ObjectOutputStream for given location which is safe and should be closed explicitly when not null given

Throws:

IOException - re-thrown

stringFromNullableLocation

public static Optional<String> stringFromNullableLocation(String location,
                                                          boolean autoGzip)

Read the contents of a location when it is not null.

Parameters:

location - A location or null

autoGzip - Wrap returned stream through autoGzip(java.io.InputStream).

Returns:

Contents

stringFromNullableLocation

public static Optional<String> stringFromNullableLocation(String location)

Read the contents of a location when it is not null.

Parameters:

location - A location or null

Returns:

Contents