Struts2整合jasperreport缓存处理方法

很多人遇到过jasperReport生成的图片会在IE下缓存,多个报表都成了同一个图片.

网上有很多是从jasperReport的编译方式入手,也可以解决.但是我这里要说的是跟Struts2整合后的解决办法,一种更简单的办法

原来我们在做报表的时候:

			<result name="success" type="result">
				<param name="location">/jasper/regUseLine.jasper</param>
				<param name="format">HTML</param>
				<param name="reportParameters">reportParameter</param>
				<param name="dataSource">chardatabean</param>
				<param name="imageServletUrl">/servlets/image?image=</param>
			</result>

struts.xml中给Action配置一个result,其中有个属性叫imageServletUrl,解决办法就是给这个请求路径加一个时间戳.

第一步,先写一个Struts2的Result,可以继承JasperReportsResult,然后覆盖里面的属性值,加一个时间戳参数.如此就解决IE下的缓存了.

package report.common.result;

import java.util.Date;

import org.apache.struts2.views.jasperreports.JasperReportsResult;

import com.opensymphony.xwork2.ActionInvocation;

@SuppressWarnings("serial")
public class JsperReportResult extends JasperReportsResult {

	@Override
	public String getImageServletUrl(){
		String[] url = this.imageServletUrl.split("\\?");
		StringBuffer t = new StringBuffer("");
		t.append(url[0]+("?_t="+(new Date()).getTime())).append("&"+url[1]);
		return t.toString();
	}
	@Override
	protected void doExecute(String finalLocation, ActionInvocation invocation)
			throws Exception {
		this.imageServletUrl = this.getImageServletUrl();
		super.doExecute(finalLocation, invocation);
	}
	
}

 第二部,修改你的struts.xml,

<package name="jasperReport" extends="struts-default,jasperreports-default">
		<result-types>
			<result-type name="jasperResult" class="report.common.result.JsperReportResult"></result-type>
		</result-types>
		<action name="HTML" class="report.actions.jsperreport.ChardataAction">
			<result name="success" type="jasperResult">
				<param name="location">/jasper/regUseLine.jasper</param>
				<param name="format">HTML</param>
				<param name="reportParameters">reportParameter</param>
				<param name="dataSource">chardatabean</param>
				<param name="imageServletUrl">/servlets/image?image=</param>
			</result>
		</action>
</package>

 注意,将你的返回类型改为你配置的result-type,我这里名字叫jasperResult