How can I get a java.io.InputStream from a java.lang.String?

Question

I have a String that I want to use as an InputStream. In Java 1.0, you could use java.io.StringBufferInputStream, but that has been @Deprecra

Answer 1

I know this is an old question but I had the same problem myself today, and this was my solution:

public static InputStream getStream(final CharSequence charSequence) {
 return new InputStream() {
  int index = 0;
  int length = charSequence.length();
  @Override public int read() throws IOException {
   return index>=length ? -1 : charSequence.charAt(index++);
  }
 };
}

Answer 2

There is an adapter from Apache Commons-IO which adapts from Reader to InputStream, which is named ReaderInputStream.

Example code:

@Test
public void testReaderInputStream() throws IOException {
    InputStream inputStream = new ReaderInputStream(new StringReader("largeString"), StandardCharsets.UTF_8);
    Assert.assertEquals("largeString", IOUtils.toString(inputStream, StandardCharsets.UTF_8));
}

Reference: https://stackoverflow.com/a/27909221/5658642