de.highbyte_le.weberknecht.request.view.JsonActionProcessor.java Source code

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Here is the source code for de.highbyte_le.weberknecht.request.view.JsonActionProcessor.java

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/*
 * JsonActionProcessor.java (weberknecht)
 *
 * Copyright 2010-2013 Patrick Mairif.
 * The program is distributed under the terms of the Apache License (ALv2).
 * 
 * tabstop=4, charset=UTF-8
 */
package de.highbyte_le.weberknecht.request.view;

import java.io.BufferedWriter;
import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONException;
import org.json.JSONWriter;

import de.highbyte_le.weberknecht.request.Executable;
import de.highbyte_le.weberknecht.request.actions.ActionExecutionException;

/**
 * process JSON views
 * 
 * @author pmairif
 */
public class JsonActionProcessor implements ActionViewProcessor {

    /* (non-Javadoc)
     * @see de.highbyte_le.weberknecht.request.ActionProcessor#processView(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, de.highbyte_le.weberknecht.request.ExecutableAction)
     */
    @Override
    public boolean processView(HttpServletRequest request, HttpServletResponse response, Executable action)
            throws IOException, ActionExecutionException {

        try {
            if (action instanceof JsonView)
                return processView(request, response, (JsonView) action);

            throw new IllegalArgumentException("Action not applicable here.");
        } catch (JSONException e) {
            throw new ActionExecutionException("JSON exception: " + e.getMessage(), e);
        }
    }

    public boolean processView(HttpServletRequest request, HttpServletResponse response, JsonView action)
            throws IOException, JSONException {

        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");

        BufferedWriter writer = null;
        try {
            writer = new BufferedWriter(response.getWriter());
            JSONWriter jsonWriter = new JSONWriter(writer);
            action.writeJson(jsonWriter);
            writer.flush();
        } finally {
            if (writer != null)
                writer.close();
        }

        return true;
    }

    /* (non-Javadoc)
     * @see de.highbyte_le.weberknecht.request.ActionViewProcessor#setServletContext(javax.servlet.ServletContext)
     */
    @Override
    public void setServletContext(ServletContext servletContext) {
        //
    }

    @Override
    public void setActionViewProcessorFactory(ActionViewProcessorFactory factory) {
        //
    }
}