In the previous tutorial, we discussed how can we convert an InputStream into a String. In this tutorial we are going to see the opposite direction. So, we are going to covert a String into an InputStream.
When you have a very big String that you want to process it incrementally, or a small portion of it at a time, converting it to an InputStream can be very helpful. In the previous tutorials what we actually did was to read the bytes from an input stream and append them to a String variable. In this tutorial we’re going to do the same technique.
Basically we are going to :
- Get the bytes of the String
- Create a new
ByteArrayInputStreamusing the bytes of theString - Assign the
ByteArrayInputStreamobject to anInputStreamvariable (which you can do asInputStreamis a superclass ofByteArrayInputStream)
Here is the code:
package com.javacodegeeks.java.core;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
public class StringToInputStream {
public static void main(String[] args) throws IOException {
String string = "This is a String.\nWe are going to convert it to InputStream.\n" +
"Greetings from JavaCodeGeeks!";
//use ByteArrayInputStream to get the bytes of the String and convert them to InputStream.
InputStream inputStream = new ByteArrayInputStream(string.getBytes(Charset.forName("UTF-8")));
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String output = bufferedReader.readLine();
while (output != null) {
System.out.println(output);
output = bufferedReader.readLine();
}
}
}Output:
This is a String. We are going to convert it to InputStream. Greetings from JavaCodeGeeks!
This was an example of how to convert String to InputStream in Java.
InputStream inputStream = new ReaderInputStream(new StringReader(string))