Read file As String

It's very easy if you use Kotlin:

val textFile = File(cacheDir, "/text_file.txt")
val allText = textFile.readText()
println(allText)

From readText() docs:

Gets the entire content of this file as a String using UTF-8 or specified charset. This method is not recommended on huge files. It has an internal limitation of 2 GB file size.


You can use org.apache.commons.io.IOUtils.toString(InputStream is, Charset chs) to do that.

e.g.

IOUtils.toString(context.getResources().openRawResource(<your_resource_id>), StandardCharsets.UTF_8)

For adding the correct library:

Add the following to your app/build.gradle file:

dependencies {
    compile 'org.apache.directory.studio:org.apache.commons.io:2.4'
}
  • https://stackoverflow.com/a/33820307/1815624

or for the Maven repo see -> this link

For direct jar download see-> https://commons.apache.org/proper/commons-io/download_io.cgi


The code finally used is the following from:

http://www.java2s.com/Code/Java/File-Input-Output/ConvertInputStreamtoString.htm

public static String convertStreamToString(InputStream is) throws Exception {
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    while ((line = reader.readLine()) != null) {
      sb.append(line).append("\n");
    }
    reader.close();
    return sb.toString();
}

public static String getStringFromFile (String filePath) throws Exception {
    File fl = new File(filePath);
    FileInputStream fin = new FileInputStream(fl);
    String ret = convertStreamToString(fin);
    //Make sure you close all streams.
    fin.close();        
    return ret;
}

Reworked the method set originating from -> the accepted answer

@JaredRummler An answer to your comment:

Read file As String

Won't this add an extra new line at the end of the string?

To prevent having a newline added at the end you can use a Boolean value set during the first loop as you will in the code example Boolean firstLine

public static String convertStreamToString(InputStream is) throws IOException {
   // http://www.java2s.com/Code/Java/File-Input-Output/ConvertInputStreamtoString.htm
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    Boolean firstLine = true;
    while ((line = reader.readLine()) != null) {
        if(firstLine){
            sb.append(line);
            firstLine = false;
        } else {
            sb.append("\n").append(line);
        }
    }
    reader.close();
    return sb.toString();
}

public static String getStringFromFile (String filePath) throws IOException {
    File fl = new File(filePath);
    FileInputStream fin = new FileInputStream(fl);
    String ret = convertStreamToString(fin);
    //Make sure you close all streams.
    fin.close();
    return ret;
}