com.diffplug.common.base

Class StringPrinter

java.lang.Object

com.diffplug.common.base.StringPrinter

public final class StringPrinter
extends Object

Pipes strings to a Consumer<String> through an API which unifies OutputStream, PrintStream, Writer, and PrintWriter.

See buildString(Consumer) for some common use cases.

Constructor Summary

Constructors

Constructor and Description
StringPrinter(Consumer<String> consumer) StringPrinter will pass all the strings it receives to the given consumer.

Method Summary

Modifier and Type	Method and Description
static String	buildString(Consumer<StringPrinter> printer) Easy way to create a String using a StringPrinter.
static String	buildStringFromLines(String... lines) Utility method for creating multi-line strings (joined with \n, never \r\n).
void	print(String content) Prints the string.
void	println(String line) Prints the string and a newline (always ‘\n’).
static Consumer<String>	stringsToLines(Consumer<String> perLine) Given a consumer of lines, creates a stateful consumer of strings which will combine its input until it finds a newline, and split its input when it contains multiple newlines.
static StringPrinter	systemErr() Creates a StringPrinter directed at System.err.
static StringPrinter	systemOut() Creates a StringPrinter directed at System.out.
OutputStream	toOutputStream() Calls toOutputStream(Charset) with charset=UTF-8.
OutputStream	toOutputStream(Charset charset) Creates an OutputStream which will print its content to this StringPrinter, encoding bytes according to the given Charset.
PrintStream	toPrintStream() Calls toPrintStream(Charset) with charset=UTF-8.
PrintStream	toPrintStream(Charset charset) Creates a PrintStream of the given charset, which passes its content to this StringPrinter.
PrintWriter	toPrintWriter() Creates a PrintWriter which passes its content to this StringPrinter.
Writer	toWriter() Creates a Writer which passes its content to this StringPrinter.

Methods inherited from class java.lang.Object

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

Constructor Detail

StringPrinter

public StringPrinter(Consumer<String> consumer)

StringPrinter will pass all the strings it receives to the given consumer.

Method Detail

println

public void println(String line)

Prints the string and a newline (always ‘\n’).

print

public void print(String content)

Prints the string.

buildString

public static String buildString(Consumer<StringPrinter> printer)

Easy way to create a String using a StringPrinter.

String currentStackTrace = StringPrinter.buildString(printer -> {
    new Throwable().printStackTrace(printer.toPrintStream());
});

buildStringFromLines

public static String buildStringFromLines(String... lines)

Utility method for creating multi-line strings (joined with \n, never \r\n).

toOutputStream

public OutputStream toOutputStream()

Calls toOutputStream(Charset) with charset=UTF-8.

toOutputStream

public OutputStream toOutputStream(Charset charset)

Creates an OutputStream which will print its content to this StringPrinter, encoding bytes according to the given Charset. Doesn’t matter if you close the stream or not, because StringPrinter doesn’t have a close().

Strings are sent to the consumer as soon as their constituent bytes are written to this OutputStream.

The implementation is lifted from Apache commons-io. Many thanks to them!

toPrintStream

public PrintStream toPrintStream()

Calls toPrintStream(Charset) with charset=UTF-8.

toPrintStream

public PrintStream toPrintStream(Charset charset)

Creates a PrintStream of the given charset, which passes its content to this StringPrinter.

Note that PrintStream.println uses the system newline, while StringPrinter.println always uses \n.

toWriter

public Writer toWriter()

Creates a Writer which passes its content to this StringPrinter.

toPrintWriter

public PrintWriter toPrintWriter()

Creates a PrintWriter which passes its content to this StringPrinter.

Note that PrintStream.println uses the system newline, while StringPrinter.println always uses \n.

stringsToLines

public static Consumer<String> stringsToLines(Consumer<String> perLine)

Given a consumer of lines, creates a stateful consumer of strings which will combine its input until it finds a newline, and split its input when it contains multiple newlines. Examples make this more clear:

"some", "\n", "simple ", "lines", "\n" -> "some", "simple lines"
"some\nsimple lines\n"                 -> "some", "simple lines"
"no newline\nno output"                -> "no newline"

Parameters:

perLine - a Consumer<String> which will receive strings which were terminated by newlines. (the newlines are stripped when they are passed to the consumer)

Returns:

a Consumer<String> which accepts any strings, and will feed them to perLine.

systemOut

public static StringPrinter systemOut()

Creates a StringPrinter directed at System.out.

systemErr

public static StringPrinter systemErr()

Creates a StringPrinter directed at System.err.