http://reluk.ca:8080/v/wap?wCall=sStore&sPut=mykey'myvalue&wPrettyThese parameters are specific to the store API. See also the general {@linkplain
* WAP WAP} parameters. Calls are conventionally prefixed by 's'
* (wCall=sStore). If you choose a different prefix, then adjust the
* parameter names below accordingly.
| Key | *Value | *Action | *
|---|---|---|
| sGet | * *A storage key, optionally followed by a guard comprising an apostrophe (') * and a value as in "sGet=address'23+Main+Street". The key may not include an * apostrophe, but the guard value may. The guard value may also be empty. | * *If no guard is specified, then it returns the currently stored value, * which may be null. If a guard is specified, then the action depends on * whether the guard value matches the stored value. If it matches, then the * stored value is returned as usual and is also deleted from the store; * otherwise null is returned and the stored value is not deleted. This is * currently the only method of deleting individual values. | * *
| sPut | * *A single key/value pair separated by an apostrophe ('), as in * "sPut=address'23+Main+Street". If multiple apostrophes are present, then the * first is taken as the separator. The key may not include an apostrophe, but * the value may. The value may also be empty. | * *Stores the value under the key and returns the same value. | * *
Any of the above parameters may be specified multiple times to multiple effect. A * request specifying "sGet=name&sGet=address", for example, will yield the values of * both "name" and "address".
* *The response includes the following components. These are shown in JSON format * with explanatory comments:
{
* "s": { // or other prefix, per {@linkplain WAP wCall} query parameter
* "value": { // keyed values:
* "KEY": "VALUE", // the typical value is a string
* "KEY": "", // the string may be empty
* "KEY": null // it may also be null, meaning nothing at all is stored
* // and so on
* }
* }
* }
*
* The response headers are set to {@linkplain ResponseConfiguration#headNoCache() * forbid client caching} and the {@linkplain ResponseConfiguration#headMustRevalidate() * use of stale responses}. However these headers are not necessarily obeyed by all * clients. Consider therefore adding a nonce * to all requests as a fallback.
*/ public @ThreadRestricted("constructor") final class StoreWAP extends Call { public static @ThreadSafe void init( final WAP wap ) throws ServletException { try { table = new StoreTable( wap ); } catch( SQLException x ) { throw new ServletException( x ); } } /** Constructs a StoreWAP. * * @see #prefix() * @see #req() */ public StoreWAP( final String prefix, final Requesting req, final ResponseConfiguration resConfig ) throws HTTPRequestException { super( prefix, req, resConfig ); final HttpServletRequest reqHS = req.request(); final String client = clientSignature( reqHS ); try { String reqName; // Put. // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - reqName = prefix() + "Put"; final String[] putArray = reqHS.getParameterValues( reqName ); if( putArray != null ) for( String put: putArray ) { final Matcher m = PUT_PATTERN.matcher( put ); if( !m.matches() ) { throw new HTTPRequestException( /*400*/HttpServletResponse.SC_BAD_REQUEST, "malformed query parameter: " + reqName + "=" + put ); } final String key = m.group( 1 ); if( key.length() > LIMIT_KEY ) { throw new HTTPRequestException( /*400*/HttpServletResponse.SC_BAD_REQUEST, "(" + reqName + ") key too long: " + key ); } final String value = m.group( 2 ); if( value.length() > LIMIT_VALUE ) { throw new HTTPRequestException( /*400*/HttpServletResponse.SC_BAD_REQUEST, "(" + reqName + ") value too long: " + value ); } table.put( client, key, value ); valueMap.put( key, value ); } // Get. // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - reqName = prefix() + "Get"; final String[] getArray = reqHS.getParameterValues( reqName ); if( getArray != null ) for( String get: getArray ) { final Matcher m = GET_PATTERN.matcher( get ); if( !m.matches() ) { throw new HTTPRequestException( /*400*/HttpServletResponse.SC_BAD_REQUEST, "malformed query parameter: " + reqName + "=" + get ); } final String key = m.group( 1 ); String value = m.group( 2 ); if( value == null ) value = table.get( client, key ); // ordinary get else if( !table.delete( client, key, value )) value = null; // guarded get valueMap.put( key, value ); } } catch( SQLException x ) { throw new RuntimeException( x ); } resConfig.headNoCache(); resConfig.headMustRevalidate(); // don't use stale values } // ------------------------------------------------------------------------------------ /** The name to use in the {@link WAP wCall} query parameter, which is {@value}. For * example:wCall=sStore.
*/
public static final String CALL_TYPE = "Store";
/** Returns the signature of the requesting client.
*/
public static String clientSignature( final HttpServletRequest reqHS )
{
final StringBuilder b = new StringBuilder();
b.append( HTTPServletRequestX.getForwardedRemoteAddr( reqHS ));
b.append( ' ' );
b.append( reqHS.getHeader( "User-Agent" ));
b.append( ' ' );
b.append( reqHS.getHeader( "Accept-Language" ));
if( b.length() > LIMIT_CLIENT ) b.setLength( LIMIT_CLIENT );
return b.toString();
}
// - C a l l --------------------------------------------------------------------------
public void respond( final Responding res ) throws java.io.IOException
{
final JsonWriter out = res.outJSON();
out.name( prefix() ).beginObject();
out.name( "value" ).beginObject();
for( final Map.Entry