RTEditor/src/main/java/com/onegravity/rteditor/utils/io/IOUtils.java
public static void writeLines(Collection<?> lines, String lineEnding,
                                  OutputStream output) throws IOException {
        writeLines(lines, lineEnding, output, Charset.defaultCharset());
    }
public static void writeLines(Collection<?> lines, String lineEnding,
                                  OutputStream output) throws IOException {
        writeLines(lines, lineEnding, output, Charset.defaultCharset());
    }
Writes the <code>toString()</code> value of each item in a collection to
an <code>OutputStream</code> line by line, using the default character
encoding of the platform and the specified line ending.

@param lines      the lines to write, null entries produce blank lines
@param lineEnding the line separator to use, null is system default
@param output     the <code>OutputStream</code> to write to, not null, not closed
@throws NullPointerException if the output is null
@throws IOException          if an I/O error occurs
@since 1.1