Comment puis-je lire / convertir un InputStream en une Chaîne en Java

Mots clés : javastringiostreaminputstreamjava

meilleur 5 Réponses Comment puis-je lire / convertir un InputStream en une Chaîne en Java

vote vote

97

 String result = IOUtils.toString(inputStream, StandardCharsets.UTF_8); 
 String result = CharStreams.toString(new InputStreamReader(        inputStream, Charsets.UTF_8)); 
 Scanner s = new Scanner(inputStream).useDelimiter("\\A");  String result = s.hasNext() ? s.next() : ""; 
 String result = new BufferedReader(new InputStreamReader(inputStream))    .lines().collect(Collectors.joining("\n")); 
 String result = new BufferedReader(new InputStreamReader(inputStream))     .lines().parallel().collect(Collectors.joining("\n")); 
 int bufferSize = 1024;  char[] buffer = new char[bufferSize];  StringBuilder out = new StringBuilder();  Reader in = new InputStreamReader(stream, StandardCharsets.UTF_8);  for (int numRead; (numRead = in.read(buffer, 0, buffer.length)) > 0; ) {      out.append(buffer, 0, numRead);  }  return out.toString(); 
 StringWriter writer = new StringWriter();  IOUtils.copy(inputStream, writer, "UTF-8");  return writer.toString(); 
 ByteArrayOutputStream result = new ByteArrayOutputStream();  byte[] buffer = new byte[1024];  for (int length; (length = inputStream.read(buffer)) != -1; ) {      result.write(buffer, 0, length);  }  // StandardCharsets.UTF_8.name() > JDK 7  return result.toString("UTF-8"); 
 String newLine = System.getProperty("line.separator");  BufferedReader reader = new BufferedReader(          new InputStreamReader(inputStream));  StringBuilder result = new StringBuilder();  for (String line; (line = reader.readLine()) != null; ) {      if (result.length() > 0) {          result.append(newLine);      }      result.append(line);  }  return result.toString(); 
BufferedInputStream bis = new BufferedInputStream(inputStream); ByteArrayOutputStream buf = new ByteArrayOutputStream(); for (int result = bis.read(); result != -1; result = bis.read()) {     buf.write((byte) result); } // StandardCharsets.UTF_8.name() > JDK 7 return buf.toString("UTF-8"); 
StringBuilder sb = new StringBuilder(); for (int ch; (ch = inputStream.read()) != -1; ) {     sb.append((char) ch); } return sb.toString(); 
              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 
               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 
 length  182    546     1092    3276    9828    29484   58968   test8  0.38    0.938   1.868   4.448   13.412  36.459  72.708  test4  2.362   3.609   5.573   12.769  40.74   81.415  159.864  test5  3.881   5.075   6.904   14.123  50.258  129.937 166.162  test9  2.237   3.493   5.422   11.977  45.98   89.336  177.39  test6  1.261   2.12    4.38    10.698  31.821  86.106  186.636  test7  1.601   2.391   3.646   8.367   38.196  110.221 211.016  test1  1.529   2.381   3.527   8.411   40.551  105.16  212.573  test3  3.035   3.934   8.606   20.858  61.571  118.744 235.428  test2  3.136   6.238   10.508  33.48   43.532  118.044 239.481  test10 1.593   4.736   7.527   20.557  59.856  162.907 323.147  test11 3.913   11.506  23.26   68.644  207.591 600.444 1211.545 
vote vote

85

StringWriter writer = new StringWriter(); IOUtils.copy(inputStream, writer, encoding); String theString = writer.toString(); 
// NB: does not close inputStream, you'll have to use try-with-resources for that String theString = IOUtils.toString(inputStream, encoding);  
vote vote

72

static String convertStreamToString(java.io.InputStream is) {     java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");     return s.hasNext() ? s.next() : ""; } 
vote vote

62

String myString = IOUtils.toString(myInputStream, "UTF-8"); 
vote vote

52

public static String slurp(final InputStream is, final int bufferSize) {     final char[] buffer = new char[bufferSize];     final StringBuilder out = new StringBuilder();     try (Reader in = new InputStreamReader(is, "UTF-8")) {         for (;;) {             int rsz = in.read(buffer, 0, buffer.length);             if (rsz < 0)                 break;             out.append(buffer, 0, rsz);         }     }     catch (UnsupportedEncodingException ex) {         /* ... */     }     catch (IOException ex) {         /* ... */     }     return out.toString(); } 

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