In Java, we can use ByteArrayInputStream to convert a String to an InputStream.
String str = "mkyong.com";
InputStream is = new ByteArrayInputStream(str.getBytes(StandardCharsets.UTF_8));
Table of contents
1. ByteArrayInputStream
This example uses ByteArrayInputStream to convert a String to an InputStream and saves it into a file.
StringToInputStream.java
package com.mkyong.string;
import java.io.*;
import java.nio.charset.StandardCharsets;
public class ConvertStringToInputStream {
public static final int DEFAULT_BUFFER_SIZE = 8192;
public static void main(String[] args) throws IOException {
String name = "mkyong.com";
// String to InputStream
InputStream is = new ByteArrayInputStream(name.getBytes(StandardCharsets.UTF_8));
// save to a file
save(is, "c:\\test\\file.txt");
}
// save the InputStream to a File
private static void save(final InputStream is, final String fileName)
throws IOException {
// read bytes from InputStream and write it to FileOutputStream
try (FileOutputStream outputStream =
new FileOutputStream(new File(fileName), false)) {
int read;
byte[] bytes = new byte[DEFAULT_BUFFER_SIZE];
while ((read = is.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
}
}
}
2. Apache Commons IO – IOUtils
This example uses commons-io library, IOUtils.toInputStream API to convert String to InputStream.
pom.xml
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.11.0</version>
</dependency>
import org.apache.commons.io.IOUtils;
// String to InputStream
InputStream result = IOUtils.toInputStream(str, StandardCharsets.UTF_8);
Review the source code of IOUtils.toInputStream, it is using the same ByteArrayInputStream to convert a String to an InputStream.
package org.apache.commons.io;
public class IOUtils {
public static InputStream toInputStream(final String input, final Charset charset) {
return new ByteArrayInputStream(input.getBytes(Charsets.toCharset(charset)));
}
//...
}
Further Reading
Convert InputStream to String in Java
Why on earth are you going to and from InputStream here? String is character-based and Reader is character-based, so having InputStream (byte-based) is an intermediate step is generally a bad idea.
You just need to do the following:
BufferedReader br = new BufferedReader(new StringReader(str));
For example, we need to convert
Stringor any character-based stream tobytesto send over the network or Internet. And many APIs accept onlyInputStream.This solution is not at all efficient. It reallocates the string’s bytes to a new array only to satisfy API constraints. Technically, it’s very easy to implement the InputStream API on top of the String itself. And the Apache Commons I/O library does just that:
String source = “String to convert to an InputStream”;
InputStream in = IOUtils.toInputStream(source, “UTF-8”);
Thanks, article is updated with
IOUtils.toInputStreamThanks man… 🙂
This was the exact thing i was looking for…..
Thanks!
Thank you