How to convert InputStream to String/convert char[] to String

This example will show you how to convert an

InputStream

to

String

. In the code snippet below we read a data.txt file, could be from common folder or from inside a jar file.

package org.kodejava.example.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.io.Writer;
import java.io.Reader;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StreamToString {

public static void main(String[] args) throws Exception {
StreamToString sts = new StreamToString();

/*
* Get input stream of our data file. This file can be in
* the root of you application folder or inside a jar file
* if the program is packed as a jar.
*/
InputStream is =
sts.getClass().getResourceAsStream("/data.txt");

/*
* Call the method to convert the stream to string
*/
System.out.println(sts.convertStreamToString(is));
}

public String convertStreamToString(InputStream is)
throws IOException {
/*
* To convert the InputStream to String we use the
* Reader.read(char[] buffer) method. We iterate until the
* Reader return -1 which means there's no more data to
* read. We use the StringWriter class to produce the string.
*/
if (is != null) {
Writer writer = new StringWriter();

char[] buffer = new char[1024];
try {
Reader reader = new BufferedReader(
new InputStreamReader(is, "UTF-8"));
int n;
while ((n = reader.read(buffer)) != -1) {
writer.write(buffer, 0, n);
}
} finally {
is.close();
}
return writer.toString();
} else {
return "";
}
}
}