In Java, we can use ByteArrayInputStream to convert a String to an InputStream.
String str = "tuts.heomi.net";
InputStream is = new ByteArrayInputStream(str.getBytes(StandardCharsets.UTF_8));1. ByteArrayInputStream
This example uses ByteArrayInputStream to convert a String to an InputStream and saves it into a file.
ConvertStringToInputStream.java
package com.favtuts.string;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
public class ConvertStringToInputStream {
public static final int DEFAULT_BUFFER_SIZE = 8192;
public static void main(String[] args) throws IOException {
String name = "tuts.heomi.net";
// String to InputStream
InputStream is = new ByteArrayInputStream(name.getBytes(StandardCharsets.UTF_8));
// current directory
Path cwd = Path.of("").toAbsolutePath();
String filePath = cwd.toString() + "/file.txt";
// save to a file
save(is, filePath);
}
// 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
Download Source Code
$ git clone https://github.com/favtuts/java-core-tutorials-examples
$ cd java-string