Java reads InputStream As string, comparing performance of various methods

Summarize other answers I found one main ways to does this (see below). and I wrote some performance tests (see results below):

Ways to convert an InputStream to a String:

Using ioutils.tostring (Apache Utils)
String result = ioutils.tostring (InputStream, standardcharsets.utf_8);
Using Charstreams (Guava)
String result = charstreams.tostring (New InputStreamReader (
InputStream, Charsets.utf_8));
Using Scanner (JDK)
Scanner s = new Scanner (inputstream). Usedelimiter ("\\a");
String result = S.hasnext ()? S.next (): "";
The Using Stream Api (Java 8). Warning:this solution convert different line breaks (like \ r \ n) to \ n.
String result = new BufferedReader (new InputStreamReader (InputStream))
. lines (). Collect (collectors.joining ("\ n"));
Using the parallel Stream Api (Java 8). Warning:this solution convert different line breaks (like \ r \ n) to \ n.
String result = new BufferedReader (new InputStreamReader (InputStream)). Lines ()
. Parallel (). Collect (collectors.joining ("\ n"));
Using InputStreamReader and StringBuilder (JDK)
Final int buffersize = 1024;
Final char[] buffer = new Char[buffersize];
Final StringBuilder out = new StringBuilder ();
Reader in = new InputStreamReader (InputStream, "UTF-8");
for (;;) {
int rsz = in.read (buffer, 0, buffer.length);
if (Rsz < 0)
Break
Out.append (buffer, 0, Rsz);
}
return out.tostring ();
Using StringWriter and Ioutils.copy (Apache Commons)
StringWriter writer = new StringWriter ();
Ioutils.copy (InputStream, writer, "UTF-8");
return writer.tostring ();
Using Bytearrayoutputstream and Inputstream.read (JDK)
Bytearrayoutputstream result = new Bytearrayoutputstream ();
byte[] buffer = new byte[1024];
int length;
while (length = inputstream.read (buffer))! =-1) {
Result.write (buffer, 0, length);
}
Return result.tostring ("UTF-8");
Using BufferedReader (JDK). Warning:this solution convert different line breaks (like \n\r) to Line.separator system property (for example, in Window S to "\ r \ n").
String newLine = System.getproperty ("Line.separator");
BufferedReader reader = new BufferedReader (new InputStreamReader (InputStream));
StringBuilder result = new StringBuilder ();
String Line; Boolean flag = false;
while (line = Reader.readline ()) = null) {
Result.append (flag newLine: ""). Append (line);
Flag = true;
}
return result.tostring ();
Using Bufferedinputstream and Bytearrayoutputstream (JDK)
Bufferedinputstream bis = new Bufferedinputstream (InputStream);
Bytearrayoutputstream buf = new Bytearrayoutputstream ();
int result = Bis.read ();
while (Result! =-1) {
Buf.write ((byte) result);
result = Bis.read ();
}
return buf.tostring ();
Using Inputstream.read () and StringBuilder (JDK). Warning:this solution have problem with Unicode, for example with Russian text (work correctly only with non-unicode text)
int ch;
StringBuilder sb = new StringBuilder ();
while ((ch = inputstream.read ())! =-1)
Sb.append ((char) ch);
Reset ();
return sb.tostring ();
Warning:

Solutions 4, 5 and 9 convert different line breaks to one.
Solution can ' t work correctly with Unicode text
Performance tests

Performance tests for small String (length = 175), URL in github (mode = Average time, system = Linux, score 1,343) Best):

Benchmark Mode Cnt score Error Units
8. Bytearrayoutputstream and read (JDK) AVGT 10 1,343±0,028 us/op
6. InputStreamReader and StringBuilder (JDK) AVGT 10 6,980±0,404 us/op
10.BufferedInputStream, Bytearrayoutputstream avgt 10 7,437±0,735 us/op
11.inputstream.read () and StringBuilder (JDK) AVGT 10 8,977±0,328 us/op
7. StringWriter and Ioutils.copy (Apache) AVGT 10 10,613±0,599 us/op
1. ioutils.tostring (Apache Utils) AVGT 10 10,605±0,527 us/op
3. Scanner (JDK) AVGT 10 12,083±0,293 us/op
2. Charstreams (Guava) AVGT 10 12,999±0,514 us/op
4. Stream Api (Java 8) AVGT 10 15,811±0,605 us/op
9. BufferedReader (JDK) AVGT 10 16,038±0,711 us/op
5. Parallel Stream Api (Java 8) AVGT 10 21,544±0,583 us/op
Performance tests for big String (length = 50100), url in github (mode = Average time, system = Linux, score 200,715 is th e best):

Benchmark Mode Cnt score Error Units
8. Bytearrayoutputstream and read (JDK) AVGT 10 200,715±18,103 us/op
1. ioutils.tostring (Apache Utils) AVGT 10 300,019±8,751 us/op
6. InputStreamReader and StringBuilder (JDK) AVGT 10 347,616±130,348 us/op
7. StringWriter and Ioutils.copy (Apache) AVGT 10 352,791±105,337 us/op
2. Charstreams (Guava) AVGT 10 420,137±59,877 us/op
9. BufferedReader (JDK) AVGT 10 632,028±17,002 us/op
5. Parallel Stream Api (Java 8) AVGT 10 662,999±46,199 us/op
4. Stream Api (Java 8) AVGT 10 701,269±82,296 us/op
10.BufferedInputStream, Bytearrayoutputstream avgt 10 740,837±5,613 us/op
3. Scanner (JDK) AVGT 10 751,417±62,026 us/op
11.inputstream.read () and StringBuilder (JDK) AVGT 10 2919,350±1101,942 us/op

Java reads InputStream As string, comparing performance of various methods