com.microsoft.azure.sdk.iot.deps.transport.http

Class HttpConnection

java.lang.Object

com.microsoft.azure.sdk.iot.deps.transport.http.HttpConnection

public class HttpConnection
extends Object

A wrapper for the Java SE class HttpsURLConnection. Used to avoid compatibility issues when testing with the mocking framework JMockit, as well as to avoid some undocumented side effects when using HttpsURLConnection.

The underlying HttpsURLConnection is transparently managed by Java. To reuse connections, for each time connect() is called, the input streams (input stream or error stream, if input stream is not accessible) must be completely read. Otherwise, the data remains in the stream and the connection will not be reusable.

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	body The body.
protected HttpsURLConnection	connection The underlying HTTPS connection.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HttpConnection()
	HttpConnection(URL url, HttpMethod method) Constructor.

Method Summary

Modifier and Type	Method and Description
void	connect() Sends the request to the URL given in the constructor.
Map<String,List<String>>	getResponseHeaders() Returns the response headers as a Map, where the key is the header field name and the values are the values associated with the header field name.
int	getResponseStatus() Returns the response status code.
byte[]	readError() Reads from the error stream and returns the error reason.
byte[]	readInput() Reads from the input stream (response stream) and returns the response.
protected static byte[]	readInputStream(InputStream stream) Reads the input stream until the stream is empty.
void	setReadTimeoutMillis(int timeout) Sets the read timeout in milliseconds.
void	setRequestHeader(String field, String value) Sets the request header field to the given value.
void	setRequestMethod(HttpMethod method) Sets the request method (i.e.
void	writeOutput(byte[] body) Saves the body to be sent with the request.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

connection

protected final HttpsURLConnection connection

The underlying HTTPS connection.

body

protected byte[] body

The body. HttpsURLConnection silently calls connect() when the output stream is written to. We buffer the body and defer writing to the output stream until connect() is called.

Constructor Detail

HttpConnection

public HttpConnection(URL url,
                      HttpMethod method)
               throws IOException

Constructor. Opens a connection to the given URL.

Parameters:

url - The URL for the HTTPS connection.

method - The HTTPS method (i.e. GET).

Throws:

IOException - This exception is thrown if the connection was unable to be opened.

HttpConnection

protected HttpConnection()

Method Detail

connect

public void connect()
             throws IOException

Sends the request to the URL given in the constructor.

Throws:

IOException - This exception thrown if the connection could not be established, or the server responded with a bad status code.

setRequestMethod

public void setRequestMethod(HttpMethod method)

Sets the request method (i.e. POST).

Parameters:

method - The request method.

Throws:

IllegalArgumentException - This exception thrown if the request currently has a non-empty body and the new method is not a POST or a PUT. This is because Java's HttpsURLConnection silently converts the HTTPS method to POST or PUT if a body is written to the request.

setRequestHeader

public void setRequestHeader(String field,
                             String value)

Sets the request header field to the given value.

Parameters:

field - The header field name.

value - The header field value.

setReadTimeoutMillis

public void setReadTimeoutMillis(int timeout)

Sets the read timeout in milliseconds. The read timeout is the number of milliseconds after the server receives a request and before the server sends data back.

Parameters:

timeout - The read timeout.

writeOutput

public void writeOutput(byte[] body)

Saves the body to be sent with the request.

Parameters:

body - The request body.

Throws:

IllegalArgumentException - if the request does not currently use method POST or PUT and the body is non-empty. This is because Java's HttpsURLConnection silently converts the HTTPS method to POST or PUT if a body is written to the request.

readInput

public byte[] readInput()
                 throws IOException

Reads from the input stream (response stream) and returns the response.

Returns:

The response body.

Throws:

IOException - This exception thrown if the input stream could not be accessed, for example if the server could not be reached.

readError

public byte[] readError()
                 throws IOException

Reads from the error stream and returns the error reason.

Returns:

The error reason.

Throws:

IOException - This exception thrown if the input stream could not be accessed, for example if the server could not be reached.

getResponseStatus

public int getResponseStatus()
                      throws IOException

Returns the response status code.

Returns:

The response status code.

Throws:

IOException - This exception thrown if no response was received.

getResponseHeaders

public Map<String,List<String>> getResponseHeaders()
                                            throws IOException

Returns the response headers as a Map, where the key is the header field name and the values are the values associated with the header field name.

Returns:

the response headers.

Throws:

IOException - This exception thrown if no response was received.

readInputStream

protected static byte[] readInputStream(InputStream stream)
                                 throws IOException

Reads the input stream until the stream is empty.

Parameters:

stream - The input stream.

Returns:

The content of the input stream.

Throws:

IOException - This exception thrown if the input stream could not be read from.