struts2-jasperreports整合说明

最近使用了jasperreports作为项目的报表工具，故写下此文以作备忘。项目采用的struts2版本为2.2.1，jasperreports版本为3.7.2。jasperreports以struts2插件的方式整合到项目中。本文只是一个简单的例子。
1. 首先，需要在项目中加入以下的jar包

其中poi.jar不是必需的，如果你要导出excel，可以加上此包。（注：所有jar包可以通过struts2-2.2.1以及ireport安装包获得）
2. 接下来是web.xml的配置，使用最基本的配置即可：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" 
xmlns="http://java.sun.com/xml/ns/j2ee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<filter>
  <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

3. 创建ReportsAction

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import net.sf.jasperreports.engine.JasperCompileManager;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class ReportsAction extends ActionSupport {
	private static final long serialVersionUID = 1L;
	//数据源
	private List<Object> list;
	//jasperreports接收的参数
	private Map<String, Object> params = new HashMap<String, Object>();
	
	public String execute() throws Exception {
		//伪代码
		list = getXXService().query...;//调用service方法
		params.put("key1", value1);
		params.put("key2", value2);
		try {
			//读取jasper模板
			String reportSource =  ServletActionContext.getServletContext().getRealPath("/jasper/report_template.xml");
			File parent = new File(reportSource).getParentFile();
			//将模板编译成jasper文件（实际项目中，jasper由ireport编译好后放入项目中，以节省编译过程所消耗的时间）
			JasperCompileManager.compileReportToFile(reportSource, new File(parent, "compiled_report.jasper").getAbsolutePath());
			
		} catch (Exception e) {
			e.printStackTrace();
			return ERROR;
		}
		return SUCCESS;
	}

	public List<Object> getList() {
		return list;
	}

	public Map<String, Object> getParams() {
		return params;
	}
	
}

4. 然后配置struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
	<!-- Configuration for the default package. -->
<struts>
	<package name="default" extends="struts-default,jasperreports-default">
		<!-- 输出不同格式的报表 -->
		<action name="PDF" class="com.actions.ReportsAction">
			<result name="success" type="jasper">
				<!-- 指定jasper文件位置 -->
				<param name="location">/jasper/compiled_report.jasper</param>
				<!-- 数据源，名称必须和Java代码中名称一致 -->
				<param name="dataSource">list</param>
				<!-- 参数，名称也必须与Java代码中名称一致 -->
				<param name="reportParameters">params</param>
				<!-- 输出格式 -->
				<param name="format">PDF</param>
			</result>
		</action>
		<action name="HTML" class="com.actions.ReportsAction">
			<result name="success" type="jasper">
				<param name="location">/jasper/compiled_report.jasper</param>
				<param name="dataSource">list</param>
				<param name="reportParameters">params</param>
				<param name="format">HTML</param>
			</result>
		</action>
		<action name="XML" class="com.actions.ReportsAction">
			<result name="success" type="jasper">
				<param name="location">/jasper/compiled_report.jasper</param>
				<param name="dataSource">list</param>
				<param name="reportParameters">params</param>
				<param name="format">XML</param>
			</result>
		</action>
		<action name="CSV" class="com.actions.ReportsAction">
			<result name="success" type="jasper">
				<param name="location">/jasper/compiled_report.jasper</param>
				<param name="dataSource">list</param>
				<param name="reportParameters">params</param>
				<param name="format">CSV</param>
			</result>
		</action>
		<action name="XLS" class="com.actions.ReportsAction">
			<result name="success" type="jasper">
				<param name="location">/jasper/compiled_report.jasper</param>
				<param name="dataSource">list</param>
				<param name="reportParameters">params</param>
				<param name="format">XLS</param>
			</result>
		</action>
	</package>
	<!-- 指定struts的扩展名，如不配置此项，可能图片无法正常显示 -->
	<constant name="struts.action.extension" value="action" />
</struts>