Chapter 18. JBPM Migration（JBPM 遷移）
Table of Contents
目錄表
Database migration
數(shù)據(jù)遷移
Process conversion
流程轉(zhuǎn)換
Extend the migration logic
擴(kuò)展遷移邏輯
The jBPM migration is considered [EXPERIMENTAL].
jBPM遷移僅作[EXPERIMENTAL]之用。
It is possible to migrate an existing installation of jBPM version 3 to Activiti. The migration includes both process definition conversion (ie. from JPDL 3 to BPMN 2.0) and data migration.
將一個(gè)已安裝的jBPM 版本3遷移到Activiti是有可能的。遷移包括流程定義轉(zhuǎn)換（例如從JPDL3到BPMN 2.0）和數(shù)據(jù)遷移。
The migration tool is currently offered as a 'preview' only! The migration coverage is at this point in time not sufficient to be usable on production process definitions and databases. Also note that the migration is a 'best effort', which means that you may need to extend the migration logic to cover all your use cases.
遷移工具目前只作為‘預(yù)覽’之用！當(dāng)前遷移不能覆蓋到產(chǎn)品的流程定義和數(shù)據(jù)。也要注意遷移是‘最大的努力’，這意味著你可以需要‘擴(kuò)展遷移邏輯’來(lái)控制你所有的用例。
The migration tool is separately availbale as a zip file from the activiti.org download site. Once you have unzipped this file, you will see following files and folders:
遷移工具從activiti.org下載站點(diǎn)以zip文件方式分開(kāi)下載。一旦加壓這個(gè)文件，文件和文件夾如下所示：
- build.xml: This ant buildfile contains the targets to execute the process definition conversion and database migration.
- build.xml: 這個(gè)ant構(gòu)建文件包含了執(zhí)行流程定義轉(zhuǎn)換和數(shù)據(jù)庫(kù)遷移的目標(biāo)。
- activiti.db.properties and jbpm3.db.properties: these properties files contain the database connection parameters for the jBPM 3 and Activiti database. These properties files must be changed when executing a database migration.
- activiti.db.properties and jbpm3.db.properties:這個(gè)特性文件包含了jBPM和Activiti數(shù)據(jù)庫(kù)的數(shù)據(jù)庫(kù)連接參數(shù)。當(dāng)執(zhí)行數(shù)據(jù)庫(kù)遷移時(shí)，必須改變這些特性文件。
- processes: when running a process definition conversion, the jBPM 3 process definition files must be placed in this folder.
- processes:當(dāng)運(yùn)行流程定義轉(zhuǎn)換時(shí)，jBPM3流程定義文件必須放置到這個(gè)文件夾。
- src: this folder contains the source code of the migration tool. Read the extension section if you want to tailor or extend the migration code to your needs.
- src:這個(gè)文件包含遷移工具的源代碼。如果希望裁剪或者擴(kuò)展遷移代碼滿足你自己的需求，請(qǐng)閱讀擴(kuò)展部分。
- lib: this folder contains all jars required to execute the migration logic.
- lib:這個(gè)文件夾包含執(zhí)行遷移邏輯的全部jar包。
Database migration
數(shù)據(jù)庫(kù)遷移
It is possible to migrate the data in the jBPM 3 database tables to the Activiti database schema. To do this, following properties files must be changed to point at the right database:
將jBPM3數(shù)據(jù)庫(kù)表遷移到Activiti數(shù)據(jù)庫(kù)schema是有可能的。為了完成這個(gè)任務(wù)，必須改變下面的properties文件，指向正確的數(shù)據(jù)庫(kù)：
- jbpm3.db.properties: contains the parameters to connect to the jBPM 3 database. Also the Hibernate dialect must be provided.
- jbpm3.db.properties:包含了連接jBPM3數(shù)據(jù)庫(kù)的參數(shù)。也必須提供Hibernate方言。
- activiti.db.properties: contains the parameters to connect to database to which the migrated data will be written. This can be the same database schema as the jBPM schema (ie. there are no name-clashes between jBPM and Activiti tables, indexes, foreign keyes, etc).
- activiti.db.properties: 包含了遷移將要寫入數(shù)據(jù)庫(kù)的連接參數(shù)。這個(gè)可能是和jBPM相同數(shù)據(jù)庫(kù)schema（例如，在jBPM和Activiti數(shù)據(jù)庫(kù)表名，索引名，外鍵名等等沒(méi)有沖突）.
The database migration will use the data in the jBPM 3 tables to:
數(shù)據(jù)遷移將使用jBPM3數(shù)據(jù)庫(kù)表的數(shù)據(jù)來(lái)做：
- Convert the process definition to the BPMN 2.0 counterpart. This means that the converted process definition will be deployed to the Activiti tables as part of the migration. As a side-effect, it will also produce the BPMN 2.0 XML files, similar to what happens when executing theprocess conversion.
- 轉(zhuǎn)換流程定義為BPMN 2.0對(duì)應(yīng)物。這意味著轉(zhuǎn)換之后的流程定義將作為遷移的一部分被部署到Activiti的數(shù)據(jù)庫(kù)表。作為副作用，它也產(chǎn)生BPMN 2.0 XML文件，這和當(dāng)執(zhí)行流程轉(zhuǎn)換時(shí)所發(fā)生的事相似。
- Migrate runtime and history data of the processes to the Activiti tables. In this release, this is not yet implemented!
- 遷移流程的運(yùn)行時(shí)和歷史數(shù)據(jù)到Activiti數(shù)據(jù)庫(kù)表。本次發(fā)布，這沒(méi)有實(shí)現(xiàn)！
The data is retrieved from the jBPM 3 tables using Hibernate queries and the Hibernate mappings of jBPM itself.
使用Hibernate查詢和jBPM自身的Hibernate映
射，可以從jBPM 3數(shù)據(jù)庫(kù)表里檢索到這些數(shù)據(jù)。
Process conversion
流程轉(zhuǎn)換
It is possible to only convert the process definitions xml from JPDL to BPMN 2.0 that can be executed on the Activiti engine. To do this, place the jBPM 3 processes inside the processes folder. There can be any number of (nested) subfolders, the tool will scan every (sub)folder inside processes to discover processdefinition.xml files (file name must be processdefinition.xml!).
只將JPDL的流程定義xml轉(zhuǎn)換為能在Activiti引擎執(zhí)行的BPMN 2.0是有可能的。為了完成這個(gè)任務(wù)，請(qǐng)將jBPM 3放置到process 文件夾。可以有任何數(shù)量（內(nèi)置）子文件夾，工具將掃描process每個(gè)（子）文件夾，來(lái)發(fā)現(xiàn)processdefinition.xml文件（文件名必須是processfinition.xml!）。
The discovered processes will be parsed and deployed to an in-memory databse, such that the logic of reverse engineering the process definition from the jBPM deployment tables contained in the database migration is used for both cases.
被發(fā)現(xiàn)的流程將被解析并部署到一個(gè)內(nèi)存數(shù)據(jù)庫(kù)，以便對(duì)包含在數(shù)據(jù)庫(kù)遷移的jBPM部署數(shù)據(jù)庫(kù)表的流程定義進(jìn)行反向工程，以為解析和部署之用。
Once the jBPM 3 processes are placed in the processes folder, execute the convert.processes target in the root of the unzipped migration tool folder:
一旦jBPM 3流程被放置到process文件夾，那么執(zhí)行在解壓之后的遷移工具文件夾根目錄下的convert.processes目標(biāo)。
ant convert.processes
During conversion, you will see plenty logging passing by describing where and how the process conversion is being executed. At the end of the conversion, you will see following logging appear:
在轉(zhuǎn)換過(guò)程中，通過(guò)描述流程轉(zhuǎn)換執(zhí)行是何地和何時(shí)轉(zhuǎn)換的方式，可以觀察到大量的日志。在轉(zhuǎn)換的末尾，將觀察到下列日志出現(xiàn)：
As shown in the logging, the resulting BPMN 2.0 processes can be find in the converted-process-xxxx folder, where the xxxx is the timestamp of the conversion.
正如日志所示，BPMN 2.0流程的結(jié)果可以在converted-process-xxxx文件夾里找到，這里xxxx是轉(zhuǎn)換的時(shí)間戳。
In this release, only limited support for start, end, wait state and task-nodes is implemented. In the future, this coverage will expand.
在本次發(fā)布里，只實(shí)現(xiàn)了對(duì)開(kāi)始，結(jié)束，等待和任務(wù)節(jié)點(diǎn)的有限支持。在將來(lái)，這個(gè)覆蓋范圍將要擴(kuò)充。