JavaArgumentsParser.java

/*
** Module   : JavaArgumentsParser.java
** Abstract : An implementation of argument parser of a REST API call implemented as a Java method.
**
** Copyright (c) 2022-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 CA  20220323 Created initial version.
**     TJD 20220504 Java 11 compatibility minor changes
** 002 SBI 20230216 Implemented defaultValue property for java parameters. 
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
**   2. No Misrepresentation of Affiliation.
** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
**     You may not represent yourself for publicity purposes as associated with
**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
** 
**   3. No Misrepresentation of Source or Origin.
** 
**     You may not represent the covered work as solely your work.  All modified
**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.rest;

import java.io.*;

import javax.servlet.http.*;

import com.goldencode.p2j.rest.serializers.*;
import com.goldencode.p2j.util.*;

/**
 * A parser for {@link JavaRestService} parameters.
 */
public class JavaArgumentsParser
extends ArgumentsParser
{
   /**
    * Create a new instance.
    * 
    * @param    serviceParser
    *           The main parser used to interpret the arguments for this service call, from the REST request.
    */
   public JavaArgumentsParser(ServiceArgumentsParser serviceParser)
   {
      super(serviceParser);
   }
   
   /**
    * Initialize this argument.
    * 
    * @param    lsp
    *           The parameter as it appears at the method's signature.
    * @param    serviceParameters
    *           The method's service parameters.
    * @param    i
    *           The parameter's index, at the method's definition.
    *           
    * @return   The initialized argument.
    */
   @Override
   public Object initArgument(LegacyServiceParameter   lsp, 
                              LegacyServiceParameter[] serviceParameters,
                              int                      i) 
   throws RequestArgumentError
   {
      JavaTypeSerializer serializer = JavaTypeSerializer.getSerializer(lsp.type(), lsp.extent());
      
      try
      {
         Object value = serializer.initialize(JavaTypeSerializer.resolveJavaType(lsp.type()));
         if (lsp.defaultValue().isEmpty())
         {
            return value;
         }
         else
         {
            return serializer.fromJson(value, lsp.defaultValue());
         }
      }
      catch (ReflectiveOperationException e)
      {
         throw new RequestArgumentError("Could not initialize argument " + lsp.ordinal(), e);
      }
   }

   /**
    * Parse the argument's value from the request.
    * 
    * @param    lsp
    *           The parameter as it appears at the method's service signature.
    * @param    original
    *           The original method's parameters.
    * @param    arg
    *           The initialized argument.
    * @param    i
    *           The parameter's index at the method's service signature.
    * @param    body
    *           The request body.
    * @param    request
    *           The request payload.
    *           
    * @return   The parsed argument.
    */
   @Override
   public Object parseArgument(LegacyServiceParameter   lsp, 
                               LegacyServiceParameter[] original, 
                               Object                   arg,
                               int                      i,
                               String                   body,
                               HttpServletRequest       request)
   throws IOException,
          RequestArgumentError
   {
      JavaTypeSerializer serializer = JavaTypeSerializer.getSerializer(lsp.type(), lsp.extent());
      String sval = serviceParser.parseArgumentInt(body, lsp.source(), request);
      
      if (sval != null)
      {
         try
         {
            return serializer.fromJson(arg, sval);
         }
         catch (Throwable t)
         {
            throw new RequestArgumentError("Could not parse [" + sval + "] for parameter " + lsp.ordinal() + 
                                           " with type " + lsp.type(), t);
         }
      }
      else
      {
         return arg;
      }
   }
}