是什么可能导致BIRT在获取和渲染之间丢失对象引用? [英] What might cause BIRT to lose an object reference between fetch and render?

问题描述

在文本末尾查看更新

我有一个脚本化数据源.数据集基于包含多个集合的Java对象.

I have a scripted data source. The datasets are based on a Java object which contains a number of collections.

我的报告包含页眉，正文和页脚，所有这些条目都具有绑定到此数据集的项目.顶级数据集存储对Java对象的引用.这被传递到子数据集，该子数据集返回各种列表.

My report contains a header, body and footer all of which have items bound to this data set. The top-level dataset stores a reference to the Java object. This is passed to sub-datasets which return various lists.

POJO

public class Protocol {
    String name;
    int id;
    List<Device> devices;
    List<TestResult> results;
    ...
}

DAO

public class DAO {
    public List<Protocol> getProtocols(String filePath) {
        return deserialise(filePath);
    }
}

协议数据集

open:
model = new Packages.com.acme.atf.model.dao.AtfObjects();

path = inputParams["ProtocolPath"];

iterP = model.getProtocols(path).iterator();
countP = 0;

fetch:
if(iterP.hasNext()) {
    var p = iterP.next();
    row["ProductId"] = p.getId();
    row["ProductVersion"] = p.getProductVersion();
    row["ProtocolObject"] = p;
    log("po=" + p);
    return true;
}
return false;

设备数据集

open:
protocol = inputParams["ProtocolObject"];
if(protocol == null) {
    log("Protocol is NULL");
    return;
}
iterD = protocol.getDevices().iterator();

日志输出记录:

po=com.acme.atf.model.Protocol@5a5901
Protocol is NULL

表示对象添加到结果中时不为null，但传递给第二个数据集时为null.

which indicates that the object is not null when added to the result but null when passed to the second dataset.

我还尝试了将Protocol数据集提取到报表中，从而创建了一个表. ProtocolObject的值已为空. (请注意，其他属性填充有合理的值)

I also tried pulling the Protocol dataset into the report, thereby creating a table. The value of ProtocolObject is already null. (Just to be clear, the other attributes are filled with sensible values)

什么可能导致row['ProtocolObject']变为空?

更新 我基于包含上述脚本的库创建了一个简单的报告.我将协议数据集作为表格插入，具有ProtocolObject的单元格为不为空！我拉入第二张表，并且两个带有ProtocolObject的单元格都为空.在日志中，我可以看到完成了2次抓取，并且每次抓取都有一个不同的Protocol实例:

UPDATE I created a simple report based on a library containing the above scripts. I pulled in the Protocol dataset as a table and the cell with ProtocolObject is not null! I pulled in a second table and both cells with ProtocolObject are null. In the logs I can see that 2 fetches are done and each gets a different Protocol instance:

Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  ===========================================
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  Open protocol: testcase.protocol
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  exit open P
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  po=com.acme.atf.model.Protocol@2892c0
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  Protocol: no more records
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  ===========================================
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  Open protocol: testcase.protocol
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  exit open P
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  po=com.acme.atf.model.Protocol@13ea352
Wed Jul 23 2014 07:28:37 GMT+0200 (CEST)  Protocol: no more records

推荐答案

我想我已经找到了原因.

I think I have found the reason.

对于某些人来说可能是显而易见的，但是原因似乎是Protocol对象不是完全可序列化的.我发现其中一个包含的类未实现java.io.Serializable.

It might be obvious to some, but the cause seems to be that the Protocol object was not fully serialisable. I found that one of the contained classes did not implement java.io.Serializable.

它可能在文档中的某个地方，但是，如果要在结果集中包含Java对象，则它必须是完全可序列化的.

It's probably in the docs somewhere but, if you want to include a Java Object in your result set, it must be completely serialisable.

这篇关于是什么可能导致BIRT在获取和渲染之间丢失对象引用?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！