Struts2和Freemarker整合应用批量静态页面的生成

利用Struts2生成静态页面其实很灵活，很强大，尤其是利用Struts2对Freemarker较好的支持，充分利用Freemarker的模板功能来生成静态页面。
基本思路为：利用Struts2对自定义result type的支持，自定义能够生成静态页面的result type，结合模板引擎Freemarker可以实现大批量静态页面的生成。
参看org.apache.struts2.views.freemarker.FreemarkerResult的代码实现，自定义了自己的生成静态页面的result type。此种方案不单纯用于生成静态页面，其实也可以用于生成诸如wml、xhtml等内容，具体可以参考Struts2缺省提供的各种result type的实现。
1、com.mobilesoft.esales.webapp.action.FreemarkerResult

package com.mobilesoft.esales.webapp.action;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Locale;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.StrutsResultSupport;
import org.apache.struts2.views.freemarker.FreemarkerManager;
import org.apache.struts2.views.util.ResourceUtil;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.LocaleProvider;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.ValueStack;
import freemarker.template.Configuration;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
public class FreemarkerResult extends StrutsResultSupport {
    private static final long serialVersionUID = -3778230771704661631L;
    protected ActionInvocation invocation;
    protected Configuration configuration;
    protected ObjectWrapper wrapper;
    protected FreemarkerManager freemarkerManager;
    private Writer writer;
    protected String location;
    private String pContentType = “text/html”;
    protected String fileName; // 要生成的静态页面名称
    protected String filePath; // 要生成的静态页面的路径
    protected String staticTemplate; // 用于生成静态页面Freemarker模板的路径
    public FreemarkerResult() {
        super();
    }
    public FreemarkerResult(String location) {
        super(location);
    }
    @Inject
    public void setFreemarkerManager(FreemarkerManager mgr) {
        this.freemarkerManager = mgr;
    }
    public void setContentType(String aContentType) {
        pContentType = aContentType;
    }
    public String getContentType() {
        return pContentType;
    }
    public void doExecute(String location, ActionInvocation invocation)
            throws IOException, TemplateException {
        this.location = location;
        this.invocation = invocation;
        this.configuration = getConfiguration();
        this.wrapper = getObjectWrapper();
        this.fileName = (String) conditionalParse(fileName, invocation);
        this.staticTemplate = (String) conditionalParse(staticTemplate, invocation);
        this.filePath = ((String) conditionalParse(filePath, invocation)) == null ? “”
                : ((String) conditionalParse(filePath, invocation));
        if (!location.startsWith(”/”)) {
            ActionContext ctx = invocation.getInvocationContext();
            HttpServletRequest req = (HttpServletRequest) ctx
                    .get(ServletActionContext.HTTP_REQUEST);
            String base = ResourceUtil.getResourceBase(req);
            location = base + “/” + location;
        }
        //生成html页面的模板类
        Template template = configuration.getTemplate(location, deduceLocale());
        // 生成静态页面的的模板类
        Template staticTemplate = configuration.getTemplate(this.staticTemplate,
                deduceLocale());
        TemplateModel model = createModel();
        String path = ServletActionContext.getServletContext().getRealPath(
                filePath)
                + File.separator;
        Writer out = new BufferedWriter(new OutputStreamWriter(
                new FileOutputStream(path + fileName)));
        if (preTemplateProcess(template, model)) {
            try {
                staticTemplate.process(model, out);
                template.process(model, getWriter());
            } finally {
                postTemplateProcess(template, model);
                postTemplateProcess(staticTemplate, model);
            }
        }
    }
    protected Configuration getConfiguration() throws TemplateException {
        return freemarkerManager.getConfiguration(ServletActionContext
                .getServletContext());
    }
    protected ObjectWrapper getObjectWrapper() {
        return configuration.getObjectWrapper();
    }
    public void setWriter(Writer writer) {
        this.writer = writer;
    }
    protected Writer getWriter() throws IOException {
        if (writer != null) {
            return writer;
        }
        return ServletActionContext.getResponse().getWriter();
    }
    protected TemplateModel createModel() throws TemplateModelException {
        ServletContext servletContext = ServletActionContext
                .getServletContext();
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        ValueStack stack = ServletActionContext.getContext().getValueStack();
        Object action = null;
        if (invocation != null)
            action = invocation.getAction(); // Added for NullPointException
        return freemarkerManager.buildTemplateModel(stack, action,
                servletContext, request, response, wrapper);
    }
    protected Locale deduceLocale() {
        if (invocation.getAction() instanceof LocaleProvider) {
            return ((LocaleProvider) invocation.getAction()).getLocale();
        } else {
            return configuration.getLocale();
        }
    }
    protected void postTemplateProcess(Template template, TemplateModel data)
            throws IOException {
    }
    protected boolean preTemplateProcess(Template template, TemplateModel model)
            throws IOException {
        Object attrContentType = template.getCustomAttribute(”content_type”);
        if (attrContentType != null) {
            ServletActionContext.getResponse().setContentType(
                    attrContentType.toString());
        } else {
            String contentType = getContentType();
            if (contentType == null) {
                contentType = “text/html”;
            }
            String encoding = template.getEncoding();
            if (encoding != null) {
                contentType = contentType + “; charset=” + encoding;
            }
            ServletActionContext.getResponse().setContentType(contentType);
        }
        return true;
    }
    public String getFileName() {
        return fileName;
    }
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
    public String getFilePath() {
        return filePath;
    }
    public void setFilePath(String filePath) {
        this.filePath = filePath;
    }
    public String getStaticTemplate() {
        return staticTemplate;
    }
    public void setStaticTemplate(String staticTemplate) {
        this.staticTemplate = staticTemplate;
    }
}

2、struts.xml

        <action name=”staticViewAction” class=”com.mobilesoft.esales.webapp.action.StaticViewtAction”>
            <result name=”success” type=”staticview”>
                <param name=”location”>test/freemarkertest.ftl</param>
                <param name=”contentType”>text/html</param>
                 <param name=”fileName”>${filename}</param>
                <param name=”staticTemplate”>test/freemarkertest.ftl</param>
                <param name=”filePath”>static</param>
            </result>                   
        </action>

评论

1 楼 maloveliu99 2009-10-30  

写个调用小例子啊！本人初学，不知道doExecute里的的两个参数要填什么啊！！谢谢