MapServer

java.lang.Object
- MapServer

```
public class MapServer
extends Object
```
This MapServer class is the entry point for running the JavaSpark web server for the BearMaps application project, receiving API calls, handling the API call processing, and generating requested images and routes.

Author:

Alan Yao

Field Summary

Fields
Modifier and Type	Field and Description
`private static GraphDB`	`g`
`private static int`	`HALT_RESPONSE` HTTP failed response.
`private static String`	`IMG_ROOT` The tile images are in the IMG_ROOT folder.
`private static String`	`OSM_DB_PATH` The OSM XML file path.
`private static String[]`	`REQUIRED_RASTER_REQUEST_PARAMS` Each raster request to the server will have the following parameters as keys in the params map accessible by, i.e., params.get("ullat") inside getMapRaster().
`private static String[]`	`REQUIRED_ROUTE_REQUEST_PARAMS` Each route request to the server will have the following parameters as keys in the params map. start_lat -> start point latitude, start_lon -> start point longitude, end_lat -> end point latitude, end_lon -> end point longitude.
`static double`	`ROOT_LRLAT` The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped.
`static double`	`ROOT_LRLON` The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped.
`static double`	`ROOT_ULLAT` The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped.
`static double`	`ROOT_ULLON` The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped.
`static Color`	`ROUTE_STROKE_COLOR` Route stroke information: Cyan with half transparency.
`static float`	`ROUTE_STROKE_WIDTH_PX` Route stroke information: typically roads are not more than 5px wide.
`static int`	`TILE_SIZE` Each tile is 256x256 pixels.

Constructor Summary

Constructors
Constructor and Description

MapServer()

Constructors
Constructor and Description
`MapServer()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static List<Long>`	`findAndDrawRoute(Map<String,Double> routeParams, Map<String,Object> rasterImageParams, BufferedImage im)` Searches for the shortest route satisfying the input request parameters, and returns a `List` of the route's node ids.
`static List<Map<String,Object>>`	`getLocations(String locationName)` Collect all locations that match a cleaned `locationName`, and return information about each node that matches.
`static List<String>`	`getLocationsByPrefix(String prefix)` In linear time, collect all the names of OSM locations that prefix-match the query string.
`static BufferedImage`	`getMapRaster(Map<String,Double> inputParams, Map<String,Object> rasteredImageParams)` Handles raster API calls, queries for tiles and rasters the full image.
`private static HashMap<String,Double>`	`getRequestParams(spark.Request req, String[] requiredParams)` Return a parameter map of the required request parameters.
`private static boolean`	`hasRequestParameters(HashMap<String,Double> params, String[] requiredParams)` Check if the computed parameter map matches the required parameters on length.
`static void`	`initialize()` Place any initialization statements that will be run before the server main loop here.
`static void`	`main(String[] args)`
`private static void`	`validateRequestParameters(HashMap<String,Double> params, String[] requiredParams)` Validate that the computed parameters matches the required parameters.
`(package private) static void`	`writeJpgToStream(BufferedImage im, OutputStream os)` Write a `BufferedImage` to an `OutputStream`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ROOT_ULLAT
```
public static final double ROOT_ULLAT
```
    The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped. Longitude == x-axis; latitude == y-axis.
    
    See Also:
    
    Constant Field Values
  - ROOT_ULLON
```
public static final double ROOT_ULLON
```
    The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped. Longitude == x-axis; latitude == y-axis.
    
    See Also:
    
    Constant Field Values
  - ROOT_LRLAT
```
public static final double ROOT_LRLAT
```
    The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped. Longitude == x-axis; latitude == y-axis.
    
    See Also:
    
    Constant Field Values
  - ROOT_LRLON
```
public static final double ROOT_LRLON
```
    The root upper left/lower right longitudes and latitudes represent the bounding box of the root tile, as the images in the img/ folder are scraped. Longitude == x-axis; latitude == y-axis.
    
    See Also:
    
    Constant Field Values
  - TILE_SIZE
```
public static final int TILE_SIZE
```
    Each tile is 256x256 pixels.
    
    See Also:
    
    Constant Field Values
  - HALT_RESPONSE
```
private static final int HALT_RESPONSE
```
    HTTP failed response.
    
    See Also:
    
    Constant Field Values
  - ROUTE_STROKE_WIDTH_PX
```
public static final float ROUTE_STROKE_WIDTH_PX
```
    Route stroke information: typically roads are not more than 5px wide.
    
    See Also:
    
    Constant Field Values
  - ROUTE_STROKE_COLOR
```
public static final Color ROUTE_STROKE_COLOR
```
    Route stroke information: Cyan with half transparency.
  - IMG_ROOT
```
private static final String IMG_ROOT
```
    The tile images are in the IMG_ROOT folder.
    
    See Also:
    
    Constant Field Values
  - OSM_DB_PATH
```
private static final String OSM_DB_PATH
```
    The OSM XML file path. Downloaded from here using custom region selection.
    
    See Also:
    
    Constant Field Values
  - REQUIRED_RASTER_REQUEST_PARAMS
```
private static final String[] REQUIRED_RASTER_REQUEST_PARAMS
```
    Each raster request to the server will have the following parameters as keys in the params map accessible by, i.e., params.get("ullat") inside getMapRaster().
    ullat -> upper left corner latitude,
    ullon -> upper left corner longitude,
    lrlat -> lower right corner latitude,
    lrlon -> lower right corner longitude
    w -> user viewport window width in pixels,
    h -> user viewport height in pixels.
  - REQUIRED_ROUTE_REQUEST_PARAMS
```
private static final String[] REQUIRED_ROUTE_REQUEST_PARAMS
```
    Each route request to the server will have the following parameters as keys in the params map.
    start_lat -> start point latitude,
    start_lon -> start point longitude,
    end_lat -> end point latitude,
    end_lon -> end point longitude.
  - g
```
private static GraphDB g
```
- Constructor Detail
  - MapServer
```
public MapServer()
```
- Method Detail
  - initialize
```
public static void initialize()
```
    Place any initialization statements that will be run before the server main loop here. Do not place it in the main function. Do not place initialization code anywhere else. This is for testing purposes, and you may fail tests otherwise.
  - main
```
public static void main(String[] args)
```
  - hasRequestParameters
```
private static boolean hasRequestParameters(HashMap<String,Double> params,
                                            String[] requiredParams)
```
    Check if the computed parameter map matches the required parameters on length.
  - validateRequestParameters
```
private static void validateRequestParameters(HashMap<String,Double> params,
                                              String[] requiredParams)
```
    Validate that the computed parameters matches the required parameters. If the parameters do not match, halt.
  - getRequestParams
```
private static HashMap<String,Double> getRequestParams(spark.Request req,
                                                       String[] requiredParams)
```
    Return a parameter map of the required request parameters. Requires that all input parameters are doubles.
    
    Parameters:
    
    req - HTTP Request
    
    requiredParams - TestParams to validate
    
    Returns:
    
    A populated map of input parameter to it's numerical value.
  - writeJpgToStream
```
static void writeJpgToStream(BufferedImage im,
                             OutputStream os)
```
    Write a BufferedImage to an OutputStream. The image is written as a lossy JPG, but with the highest quality possible.
    
    Parameters:
    
    im - Image to be written.
    
    os - Stream to be written to.
  - getMapRaster
```
public static BufferedImage getMapRaster(Map<String,Double> inputParams,
                                         Map<String,Object> rasteredImageParams)
```
    Handles raster API calls, queries for tiles and rasters the full image.
    
    The rastered photo must have the following properties:
    - Has dimensions of at least w by h, where w and h are the user viewport width and height.
    - The tiles collected must cover the most longitudinal distance per pixel possible, while still covering less than or equal to the amount of longitudinal distance per pixel in the query box for the user viewport size.
    - Contains all tiles that intersect the query bounding box that fulfill the above condition.
    - The tiles must be arranged in-order to reconstruct the full image.
    Additional image about the raster is returned and is to be included in the Json response.
    Parameters:
    
    inputParams - Map of the HTTP GET request's query parameters - the query bounding box and the user viewport width and height.
    
    rasteredImageParams - This is constructed beforehand and passed in as an empty map.
    After execution, it is a map of parameters for the Json response which is populated by this method as specified:
    "raster_ul_lon" - Double, the bounding upper left longitude of the rastered image
    "raster_ul_lat" - Double, the bounding upper left latitude of the rastered image
    "raster_lr_lon" - Double, the bounding lower right longitude of the rastered image
    "raster_lr_lat" - Double, the bounding lower right latitude of the rastered image
    "raster_width" - Integer, the width of the rastered image
    "raster_height" - Integer, the height of the rastered image
    "depth" - Integer, the length of the numbers in the image name string.
    "query_success" - Boolean, whether an image was successfully rastered.
    
    Returns:
    
    a BufferedImage, which is the rastered result.
    
    See Also:
    
    REQUIRED_RASTER_REQUEST_PARAMS
  - findAndDrawRoute
```
public static List<Long> findAndDrawRoute(Map<String,Double> routeParams,
                                          Map<String,Object> rasterImageParams,
                                          BufferedImage im)
```
    Searches for the shortest route satisfying the input request parameters, and returns a List of the route's node ids.
    The route should start from the closest node to the start point and end at the closest node to the endpoint. Distance is defined as the euclidean distance between two points (lon1, lat1) and (lon2, lat2). If im is not null, draw the route onto the image by drawing lines in between adjacent points in the route. The lines should be drawn using ROUTE_STROKE_COLOR, ROUTE_STROKE_WIDTH_PX, BasicStroke.CAP_ROUND and BasicStroke.JOIN_ROUND.
    
    Parameters:
    
    routeParams - Params collected from the API call. Members are as described in REQUIRED_ROUTE_REQUEST_PARAMS.
    
    rasterImageParams - parameters returned from the image rastering.
    
    im - The rastered map image to be drawn on.
    
    Returns:
    
    A List of node ids from the start of the route to the end.
  - getLocationsByPrefix
```
public static List<String> getLocationsByPrefix(String prefix)
```
    In linear time, collect all the names of OSM locations that prefix-match the query string.
    
    Parameters:
    
    prefix - Prefix string to be searched for. Could be any case, with our without punctuation.
    
    Returns:
    
    A List of the full names of locations whose cleaned name matches the cleaned prefix.
  - getLocations
```
public static List<Map<String,Object>> getLocations(String locationName)
```
    Collect all locations that match a cleaned locationName, and return information about each node that matches.
    
    Parameters:
    
    locationName - A full name of a location searched for.
    
    Returns:
    
    A list of locations whose cleaned name matches the cleaned locationName, and each location is a map of parameters for the Json response as specified:
    "lat" -> Number, The latitude of the node.
    "lon" -> Number, The longitude of the node.
    "name" -> String, The actual name of the node.
    "id" -> Number, The id of the node.

Class MapServer

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ROOT_ULLAT

ROOT_ULLON

ROOT_LRLAT

ROOT_LRLON

TILE_SIZE

HALT_RESPONSE

ROUTE_STROKE_WIDTH_PX

ROUTE_STROKE_COLOR

IMG_ROOT

OSM_DB_PATH

REQUIRED_RASTER_REQUEST_PARAMS

REQUIRED_ROUTE_REQUEST_PARAMS

g

Constructor Detail

MapServer

Method Detail

initialize

main

hasRequestParameters

validateRequestParameters

getRequestParams

writeJpgToStream

getMapRaster

findAndDrawRoute

getLocationsByPrefix

getLocations