serendip.struts.plugins.thymeleaf.ThymeleafSpringResult.java Source code

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Here is the source code for serendip.struts.plugins.thymeleaf.ThymeleafSpringResult.java

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/*
 * Copyright 2013 Steven Benitez.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package serendip.struts.plugins.thymeleaf;

import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

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

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.StrutsConstants;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.spring4.context.SpringWebContext;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.LocaleProvider;
import com.opensymphony.xwork2.Result;
import com.opensymphony.xwork2.inject.Inject;

import serendip.struts.plugins.thymeleaf.spi.TemplateEngineProvider;

/**
 * Renders a Thymeleaf-Spring template as the result of invoking a Struts action.
 *
 * @author A-pZ ( Original source : Steven Benitez )
 */
public class ThymeleafSpringResult implements Result {
    private String defaultEncoding = "UTF-8";
    private TemplateEngineProvider templateEngineProvider;
    private String templateName;

    /**
     * The result parameter name to set the name of the template to.
     *
     * IMPORTANT! Struts2 will look for this field reflectively to determine
     * which parameter is the default. This allows us to have a simplified
     * result configuration. Don't remove it!
     */
    public static final String DEFAULT_PARAM = "templateName";

    /** instance name of struts2-action */
    public static final String ACTION_VARIABLE_NAME = "action";

    /** field errors */
    public static final String FIELD_ERRORS_NAME = "field";

    /** struts2 convertion errors fields and value */
    public static final String OVERRIDES_NAME = "overrides";

    public ThymeleafSpringResult() {
    }

    public ThymeleafSpringResult(String templateName) {
        this.templateName = templateName;
    }

    @Override
    public void execute(ActionInvocation actionInvocation) throws Exception {
        TemplateEngine templateEngine = templateEngineProvider.get();

        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        ServletContext servletContext = ServletActionContext.getServletContext();

        Object action = actionInvocation.getAction();

        // Action instance put to Thymeleaf context.
        Map<String, Object> variables = bindStrutsContest(action);

        // Locale by Struts2-Action.
        Locale locale = ((LocaleProvider) action).getLocale();

        // Spring-ApplicationContext.
        //ApplicationContext appctx = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
        ApplicationContext appctx = (ApplicationContext) servletContext
                .getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);

        // Use SpringWebContext( by Thymeleaf-spring plugin. )
        SpringWebContext context = new SpringWebContext(request, response, servletContext, locale, variables,
                appctx);

        // response to TemplateEngine.
        response.setContentType("text/html");
        response.setCharacterEncoding(defaultEncoding);
        templateEngine.process(templateName, context, response.getWriter());
    }

    @Inject(StrutsConstants.STRUTS_I18N_ENCODING)
    public void setDefaultEncoding(String defaultEncoding) {
        this.defaultEncoding = defaultEncoding;
    }

    @Inject
    public void setTemplateEngineProvider(TemplateEngineProvider templateEngineProvider) {
        this.templateEngineProvider = templateEngineProvider;
    }

    public void setTemplateName(String templateName) {
        this.templateName = templateName;
    }

    /**
     * Binding Struts2 action and context, and field-errors list binding "field".
     * @param action Action instance
     * @return ContextMap
     */
    Map<String, Object> bindStrutsContest(Object action) {
        Map<String, Object> variables = new HashMap<String, Object>();
        variables.put(ACTION_VARIABLE_NAME, action);

        if (action instanceof ActionSupport) {
            ActionSupport actSupport = (ActionSupport) action;

            // Struts2 field errors.( Map<fieldname , fielderrors>)
            Map<String, List<String>> fieldErrors = actSupport.getFieldErrors();
            variables.put(FIELD_ERRORS_NAME, fieldErrors);
        }

        return variables;
    }
}