Below are some Java examples of converting InputStream to a File.
1. Plain Java – FileOutputStream
This example downloads the google.com HTML page and returns it as an InputStream. And we use FileOutputStream to copy the InputStream into a File, and save it somewhere.
InputStreamToFile1.java
package com.favtuts.io.howto;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
public class InputStreamToFile1 {
/**
* The default buffer size
*/
public static final int DEFAULT_BUFFER_SIZE = 8192;
public static void main(String[] args) throws IOException {
URI u = URI.create("https://www.google.com/");
try (InputStream inputStream = u.toURL().openStream()) {
File file = new File("/home/tvt/workspace/favtuts/google.txt");
copyInputStreamToFile(inputStream, file);
}
}
private static void copyInputStreamToFile(InputStream inputStream, File file) throws IOException {
// append = false
try (FileOutputStream outputStream = new FileOutputStream(file, false)) {
int read;
byte[] bytes = new byte[DEFAULT_BUFFER_SIZE];
while((read = inputStream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
}
}
}
2. Apache Commons IO
If there is Apache Commons IO in the project, we can use the FileUtils.copyInputStreamToFile to copy the InputStream into a File.
pom.xml
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.7</version>
</dependency>
InputStreamToFile2.java
package com.favtuts.io.howto;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
public class InputStreamToFile2 {
public static void main(String[] args) throws IOException {
URI u = URI.create("https://www.google.com/");
try (InputStream inputStream = u.toURL().openStream()) {
File file = new File("/home/tvt/workspace/favtuts/google.txt");
// commons-io
FileUtils.copyInputStreamToFile(inputStream, file);
}
}
}
3. Java 1.7 – Files.copy
In Java 1.7, we can use the Files.copy to copy the InputStream to a Path.
InputStreamToFile3.java
URI u = URI.create("https://www.google.com/");
try (InputStream inputStream = u.toURL().openStream()) {
File file = new File("/home/tvt/workspace/favtuts/google.txt");
// Java 1.7
Files.copy(inputStream, file.toPath(), StandardCopyOption.REPLACE_EXISTING);
}
4. Java 9 – InputStream.transferTo
In Java 9, we can use the new InputStream#transferTo to copy the InputStream to an OutputStream directly.
InputStreamToFile4.java
package com.favtuts.io.howto;
import java.io.*;
import java.net.URI;
public class InputStreamToFile4 {
public static void main(String[] args) throws IOException {
URI u = URI.create("https://www.google.com/");
try (InputStream inputStream = u.toURL().openStream()) {
File file = new File("/home/tvt/workspace/favtuts/google.txt");
// Java 9
copyInputStreamToFileJava9(inputStream, file);
}
}
// Java 9
private static void copyInputStreamToFileJava9(InputStream input, File file)
throws IOException {
// append = false
try (OutputStream output = new FileOutputStream(file, false)) {
input.transferTo(output);
}
}
}
5. Convert File to InputStream
We can use FileInputStream to convert a File to an InputStream.
File file = new File("/home/tvt/workspace/favtuts/google.txt");
InputStream inputStream = new FileInputStream(file);Download Source Code
$ git clone https://github.com/favtuts/java-core-tutorials-examples
$ cd java-io/howto