com.stripe.net.MultipartProcessor Maven / Gradle / Ivy
package com.stripe.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.URLConnection;
import java.util.Random;
public class MultipartProcessor {
private final String boundary;
private static final String LINE_BREAK = "\r\n";
private OutputStream outputStream;
private PrintWriter writer;
/**
* Generates a random MIME multipart boundary.
*
* @return boundary value
*/
public static String getBoundary() {
Random random = new Random();
Long positiveRandomLong = random.nextLong();
positiveRandomLong = (positiveRandomLong == Long.MIN_VALUE) ? 0 : Math.abs(positiveRandomLong);
return String.valueOf(positiveRandomLong);
}
/** Constructs a new multipart body builder. */
public MultipartProcessor(java.net.HttpURLConnection conn, String boundary, String charset)
throws IOException {
this.boundary = boundary;
this.outputStream = conn.getOutputStream();
this.writer = new PrintWriter(new OutputStreamWriter(outputStream, charset), true);
}
/**
* Adds a form field to the multipart message.
*
* @param name field name
* @param value field value
*/
public void addFormField(String name, String value) {
writer.append("--" + boundary).append(LINE_BREAK);
writer.append("Content-Disposition: form-data; name=\"" + name + "\"").append(LINE_BREAK);
writer.append(LINE_BREAK);
writer.append(value).append(LINE_BREAK);
writer.flush();
}
/**
* Adds a file field to the multipart message, but takes in an InputStream instead of just a file
* to read bytes from.
*
* @param name Field name
* @param fileName Name of the "file" being uploaded.
* @param inputStream Stream of bytes to use in place of a file.
* @throws IOException Thrown when writing / reading from streams fails.
*/
public void addFileField(String name, String fileName, InputStream inputStream)
throws IOException {
writer.append("--").append(boundary).append(LINE_BREAK);
writer
.append("Content-Disposition: form-data; name=\"")
.append(name)
.append("\"; filename=\"")
.append(fileName)
.append("\"")
.append(LINE_BREAK);
String probableContentType = URLConnection.guessContentTypeFromName(fileName);
writer.append("Content-Type: ").append(probableContentType).append(LINE_BREAK);
writer.append("Content-Transfer-Encoding: binary").append(LINE_BREAK);
writer.append(LINE_BREAK);
writer.flush();
streamToOutput(inputStream);
writer.append(LINE_BREAK);
writer.flush();
}
/**
* Utility method to read all the bytes from an InputStream into the outputStream.
*
* @param inputStream Stream of bytes to read from.
* @throws IOException Thrown on errors reading / writing.
*/
private void streamToOutput(InputStream inputStream) throws IOException {
try {
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
} finally {
inputStream.close();
}
}
/** Adds the final boundary to the multipart message and closes streams. */
public void finish() throws IOException {
writer.append("--" + boundary + "--").append(LINE_BREAK);
writer.flush();
writer.close();
outputStream.flush();
outputStream.close();
}
}