/*
 * Copyright (c) 2004 Your Corporation. All Rights Reserved.
 */
package com.jetmaven.oa;

import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

/**
 * @author <a href="mailto:youmail@yourdomain.com">yourname</a> Date: 2004-11-22
 */
public class ViewJasperReportController implements Controller
{
    private DataSource dataSource;

    public DataSource getDataSource()
    {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource)
    {
        this.dataSource = dataSource;
    }

    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception
    {
        String relativeUri = request.getRequestURI().replaceFirst(request.getContextPath(), "");
        File reportFilePath = new File(request.getSession(true).getServletContext().getRealPath(relativeUri));
        if (reportFilePath.exists())  //jasper文件存在
        {
            OutputStream out = response.getOutputStream();
            response.setContentType("application/pdf");
            Connection conn = DataSourceUtils.getConnection(dataSource);
            try
            {
                JasperPrint jasperPrint = JasperFillManager.fillReport(new FileInputStream(reportFilePath), convertRequestParamAndAttrToMap(request), conn);
                JasperExportManager.exportReportToPdfStream(jasperPrint, out);
                out.flush();
            } finally
            {
                DataSourceUtils.closeConnectionIfNecessary(conn, dataSource);
            }
        } else     //jasper文件不存在
        {
            setError404(response);
        }
        return null;
    }

    /**
     * 设置404错误，指定的jasper文件未找到
     *
     * @param response web的response变量
     * @throws java.io.IOException 异常
     */
    private void setError404(HttpServletResponse response) throws IOException
    {
        response.setContentType("text/html;charset=gb2312");
        response.setStatus(404);
        response.getOutputStream().write("Error:404,File not Found!".getBytes());
    }

    /**
     * 将request的参数和属性转换成Map
     *
     * @param request web的request变量
     * @return Map的对象
     */
    private Map convertRequestParamAndAttrToMap(HttpServletRequest request)
    {
        Map paramAndAttr = new HashMap();
        //填充属性
        Enumeration allAttrKey = request.getAttributeNames();
        while (allAttrKey.hasMoreElements())
        {
            String attrKey = (String) allAttrKey.nextElement();
            paramAndAttr.put(attrKey, request.getAttribute(attrKey));
        }
        return paramAndAttr;
    }
}