de.gerdiproject.harvest.utils.data

Class HttpRequester

java.lang.Object

de.gerdiproject.harvest.utils.data.HttpRequester

public class HttpRequester
extends Object

This class serves as a facade for HTTP requests.

Author:

Robin Weiss

Constructor Summary

Constructors

Constructor and Description
HttpRequester() Constructor that uses an UTF-8 charset, and a Gson implementation that can parse Geometry objects.
HttpRequester(com.google.gson.Gson gson, Charset httpCharset) Constructor that allows to customize the behavior.
HttpRequester(HttpRequester other) Constructor that copies the settings from another HttpRequester.

Method Summary

Modifier and Type	Method and Description
File	getCacheFolder()
org.jsoup.nodes.Document	getHtmlFromUrl(String url) Sends a GET request to a specified URL and tries to retrieve the HTML response.
<T> T	getObjectFromUrl(String url, Class<T> targetClass) Sends a GET request to a specified URL and tries to retrieve the JSON response, mapping it to a Java object.
<T> T	getObjectFromUrl(String url, Type targetType) Sends a GET request to a specified URL and tries to retrieve the JSON response, mapping it to a Java object.
Map<String,List<String>>	getRestHeader(RestRequestType method, String url, String body) Sends a REST request with a plain-text body and returns the header fields.
Map<String,List<String>>	getRestHeader(RestRequestType method, String url, String body, String authorization, String contentType) Sends an authorized REST request with a specified body and returns the header fields.
String	getRestResponse(RestRequestType method, String url, String body) Sends an REST request with a plain-text body.
String	getRestResponse(RestRequestType method, String url, String body, String authorization, String contentType) Sends an authorized REST request with a specified body and returns the response as a string.
boolean	isReadingFromDisk() Returns true if HTTP responses are read from a cache on disk.
boolean	isWritingToDisk() Returns true if HTTP responses are written to a cache on disk.
void	setCacheFolder(File cacheFolder)
void	setCharset(Charset httpCharset) Changes the charset that is used for reading and writing responses.
void	setTimeout(int timeout) Changes the request timeout for web requests.

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpRequester

public HttpRequester()

Constructor that uses an UTF-8 charset, and a Gson implementation that can parse Geometry objects.

HttpRequester

public HttpRequester(com.google.gson.Gson gson,
                     Charset httpCharset)

Constructor that allows to customize the behavior.

Parameters:

gson - the GSON (de-)serializer for reading and writing JSON objects

httpCharset - the encoding charset

HttpRequester

public HttpRequester(HttpRequester other)

Constructor that copies the settings from another HttpRequester.

Parameters:

other - the HttpRequester from which the settings are copied

Method Detail

getHtmlFromUrl

public org.jsoup.nodes.Document getHtmlFromUrl(String url)

Sends a GET request to a specified URL and tries to retrieve the HTML response. If the development option is enabled, the response will be read from disk instead.

Parameters:

url - a URL that returns a JSON object

Returns:

a JSON object, or null if the HTML document could not be retrieved

getObjectFromUrl

public <T> T getObjectFromUrl(String url,
                              Class<T> targetClass)

Sends a GET request to a specified URL and tries to retrieve the JSON response, mapping it to a Java object. If the development option is enabled, the response will be read from disk instead.

Type Parameters:

T - the type of the returned object

Parameters:

url - a URL that returns a JSON object

targetClass - the class of the returned object

Returns:

a Java object, or null if the object could not be loaded or parsed

getObjectFromUrl

public <T> T getObjectFromUrl(String url,
                              Type targetType)

Sends a GET request to a specified URL and tries to retrieve the JSON response, mapping it to a Java object. If the development option is enabled, the response will be read from disk instead.

Type Parameters:

T - the type of the returned object

Parameters:

url - a URL that returns a JSON object

targetType - the type of the returned object

Returns:

a Java object, or null if the object could not be loaded or parsed

getRestResponse

public String getRestResponse(RestRequestType method,
                              String url,
                              String body)
                       throws HTTPException,
                              IOException

Sends an REST request with a plain-text body.

Parameters:

method - the request method that is being sent

url - the URL to which the request is being sent

body - the plain-text body of the request

Returns:

the HTTP response as plain text

Throws:

HTTPException - thrown if the response code is not 2xx

IOException - thrown if the response output stream could not be created

getRestResponse

public String getRestResponse(RestRequestType method,
                              String url,
                              String body,
                              String authorization,
                              String contentType)
                       throws HTTPException,
                              IOException

Sends an authorized REST request with a specified body and returns the response as a string.

Parameters:

method - the request method that is being sent

url - the URL to which the request is being sent

body - the body of the request

authorization - the base-64-encoded username and password, or null if no authorization is required

contentType - the contentType of the body

Returns:

the HTTP response as plain text

Throws:

HTTPException - thrown if the response code is not 2xx

IOException - thrown if the response output stream could not be created

getRestHeader

public Map<String,List<String>> getRestHeader(RestRequestType method,
                                              String url,
                                              String body)
                                       throws HTTPException,
                                              IOException

Sends a REST request with a plain-text body and returns the header fields.

Parameters:

method - the request method that is being sent

url - the URL to which the request is being sent

body - the plain-text body of the request

Returns:

the response header fields, or null if the response could not be parsed

Throws:

HTTPException - thrown if the response code is not 2xx

IOException - thrown if the response output stream could not be created

getRestHeader

public Map<String,List<String>> getRestHeader(RestRequestType method,
                                              String url,
                                              String body,
                                              String authorization,
                                              String contentType)
                                       throws HTTPException,
                                              IOException

Sends an authorized REST request with a specified body and returns the header fields.

Parameters:

method - the request method that is being sent

url - the URL to which the request is being sent

body - the body of the request

authorization - the base-64-encoded username and password, or null if no authorization is required

contentType - the contentType of the body

Returns:

the response header fields, or null if the response could not be parsed

Throws:

HTTPException - thrown if the response code is not 2xx

IOException - thrown if the response output stream could not be created

setTimeout

public void setTimeout(int timeout)

Changes the request timeout for web requests.

Parameters:

timeout - the request timeout in milliseconds

isReadingFromDisk

public boolean isReadingFromDisk()

Returns true if HTTP responses are read from a cache on disk.

Returns:

true if HTTP responses are read from a cache on disk

isWritingToDisk

public boolean isWritingToDisk()

Returns true if HTTP responses are written to a cache on disk.

Returns:

true if HTTP responses are written to a cache on disk

setCharset

public void setCharset(Charset httpCharset)

Changes the charset that is used for reading and writing responses.

Parameters:

httpCharset - the charset that is used for reading and writing responses

getCacheFolder

public File getCacheFolder()

setCacheFolder

public void setCacheFolder(File cacheFolder)