jasper report 子报表中嵌套子报表

上篇记录了主报表中嵌套子报表，用json数据源设计报表，没有问题了。

本篇记录下子报表中再嵌套子报表（即孙报表）怎么实现。

思路：把需要再嵌套孙报表的子报表sub_report3，当做主报表设计，内嵌的孙报表同样用分组布局放置。

1、设计sub_report3报表布局

如下图所示：

建立了2个group，要嵌入4个子报表。

sub_report3的json数据源如下：

{"data":{"isImport":"true","applyer":"张三","applyTime":"2020-09-26 10:11:11","chiefer":"李四","chiefTime":"2020-09-26 11:11:11","pm":"王五","pmTime":"2020-09-26 12:11:11","lineItems1":[{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听1","userName":"紫薯1"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听2","userName":"紫薯"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听3","userName":"紫薯2"}],"lineItems2":[{"isAgree":"不同意","signRemark":"这就是我要发表的意见，听不听4","userName":"紫薯1"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听6","userName":"紫薯3"}],"lineItems3":[{"isAgree":"不同意","signRemark":"这就是我要发表的意见，听不听5","userName":"紫薯2"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听7","userName":"紫薯4"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听8","userName":"紫薯5"}],"lineItems4":[{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听9","userName":"紫薯6"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听2","userName":"紫薯3"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听6","userName":"紫薯4"}]}
}

布局设计的几点：

1）本例中主报表的内容宽度：550px，所有子报表的内容宽度也是550px。所以各个元素的设计宽度都是按照这个尺寸来的。

部门一列：100px；意见列：360px（4个90px）；签字列：90px

2）部门列：StaticText，高度不固定

Stretch Type属性：ContainerHeight，边框：上、左、右有边框线，底部没有。

2、创建4个子报表

4个主报表设计如下图所示：

子报表的页面设置：margins 都设置为0

3、子报表与孙报表数据关联

1）添加子报表控件，选择已经存在的子报表文件：

2）Use a JRDatasource expression：

((net.sf.jasperreports.engine.data.JsonDataSource)$P{REPORT_DATA_SOURCE}).subDataSource("lineItems1")

3）设置Dataset Parameters

预览sub_report3报表：

4、关联主报表的数据源

首先将数据整合在同一个json数据源，如下：

test3是sub_report3的数据源。

{"data":{"topic":"我就是可爱的topic","serialNo":"A98K-002-001","isImport":"true","isChecked":"false","noReason":"之所以没选中，是为了测试","test1":[{"field1":"我是field1-row1","field2":"我是field2-row1","field3":"我是field3-row1","field4":"我是field4-row1","field5":"我是field5-row1"},{"field1":"我是field1-row2","field2":"我是field2-row2","field3":"我是field3-row2","field4":"我是field4-row2","field5":"我是field5-row2"},{"field1":"我是field1-row3","field2":"我是field2-row3","field3":"我是field3-row3","field4":"我是field4-row3","field5":"我是field5-row3"}],"test2":[{"name":"MISS李","tel":"12345678","email":"12345689@qq.com"},{"name":"MISS张","tel":"12345679","email":"12356789@qq.com"},{"name":"MISS王","tel":"12345689","email":"12346789@qq.com"}],"test3":{"isImport":"true","applyer":"张三","applyTime":"2020-09-26 10:11:11","chiefer":"李四","chiefTime":"2020-09-26 11:11:11","pm":"王五","pmTime":"2020-09-26 12:11:11","lineItems1":[{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听1","userName":"紫薯1"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听2","userName":"紫薯"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听3","userName":"紫薯2"}],"lineItems2":[{"isAgree":"不同意","signRemark":"这就是我要发表的意见，听不听4","userName":"紫薯1"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听6","userName":"紫薯3"}],"lineItems3":[{"isAgree":"不同意","signRemark":"这就是我要发表的意见，听不听5","userName":"紫薯2"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听7","userName":"紫薯4"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听8","userName":"紫薯5"}],"lineItems4":[{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听9","userName":"紫薯6"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听2","userName":"紫薯3"},{"isAgree":"同意","signRemark":"这就是我要发表的意见，听不听6","userName":"紫薯4"}]}}
}

整合到主报表后，预览，报错：

抛出 net.sf.jasperreports.engine.JRException: Resource not found at: xxx.jasper 异常。

原因：主报表找不到孙报表的编译文件

解决办法：

在主报表中设置变量：SUBREPORT_DIR（若不存在则新建），代表子报表模板文件的真实路径。

设置子报表的属性Subreport Expression 的值为：$P{SUBREPORT_DIR} + "/sub_report3.jasper"，通过程序动态设置SUBREPORT_DIR,使得主报表能够获得子报表模板文件的真实路径。

传递参数：

将SUBREPORT_DIR参数一层一层传递下去。

这样子报表嵌套子报表就可以显示数据啦