前言

呵呵 这里会大致的跟一些 可能有帮助于理解 使用 maven 来管理 rcp 项目的依赖 的一些记录信息  

当然 不了解也没关系 

业务代码使用 sqlite.JDBC

看 sqlite.JDBC 的加载 

可以看到的是 Activator 触发了 sqlite.JDBC 的加载 

这里面的 Classloader 实例, ModuleClassLoader 的实例, 实际上的实现是 org.eclipse.osgi.internal.loader.EquinoxClassLoader 

可以看到这一系列的加载非常复杂, 我们还是看一些重点吧, 类加载的路由部分主要是委托给了这里的 ClasspathManager 来寻找 

从下面的图片也可以看到, 这里的 cpEntries 大概是有 31 个, 对应的就是 各个 jar, 也就是我们 pom.xml 里面配置的各个 plugin.jar 以及 sqlite.jar 以及 commons-io.jar 可以参见后面的 "cpEntries 包含了那些?" 

可以看到的是在 /Users/jerry/.m2/repository/org/xerial/sqlite-jdbc/3.32.3.2/sqlite-jdbc-3.32.3.2.jar 中发现了 sqlite.JDBC, 然后 就走了后面的从 sqlite-jdbc-3.32.3.2.jar 中加载 sqlite.JDBC defineClass 的相关流程 

cpEntries 包含了那些数据?

我们这里吧 cpEntries 列出来 大致的结构是 

*.plugin.* 相关的差不多是 24 个依赖 

sqlite.jar, commons-io.jar 两个业务依赖 

idea_rt.jar 一个 jdk 的基础依赖 

$base.dir/target/classes, $base.dir, $base.dir[target/classes], $base.dir/libs/sqlite.jar 四个其他依赖

0 = "/Users/jerry/EclipseWorkStations/MyRcp/target/classes"
1 = "/Users/jerry/.p2/pool/plugins/org.eclipse.equinox.launcher_1.6.0.v20200915-1508.jar"
2 = "/Users/jerry/.p2/pool/plugins/javax.inject_1.0.0.v20091030.jar"
3 = "/Users/jerry/.p2/pool/plugins/org.eclipse.swt_3.115.100.v20201202-1103.jar"
4 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.model.workbench_2.1.900.v20201014-0742.jar"
5 = "/Users/jerry/.p2/pool/plugins/org.eclipse.jface_3.22.0.v20201106-0834.jar"
6 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.services_1.4.0.v20201014-0944.jar"
7 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench_1.12.0.v20201119-1132.jar"
8 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di_1.7.600.v20200428-0912.jar"
9 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.di_1.2.900.v20201021-1339.jar"
10 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.contexts_1.8.400.v20191217-1710.jar"
11 = "/Users/jerry/.p2/pool/plugins/org.eclipse.core.runtime_3.20.0.v20201027-1526.jar"
12 = "/Users/jerry/.p2/pool/plugins/org.eclipse.core.commands_3.9.800.v20201021-1339.jar"
13 = "/Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di.annotations_1.6.600.v20191216-2352.jar"
14 = "/Users/jerry/.p2/pool/plugins/org.eclipse.osgi_3.16.100.v20201030-1916.jar"
15 = "/Users/jerry/.p2/pool/plugins/org.eclipse.osgi.compatibility.state_1.2.200.v20200915-2015.jar"
16 = "/Users/jerry/.p2/pool/plugins/org.eclipse.equinox.common_3.14.0.v20201102-2053.jar"
17 = "/Users/jerry/.p2/pool/plugins/org.eclipse.core.jobs_3.10.1000.v20200909-1312.jar"
18 = "/Users/jerry/.p2/pool/plugins/org.eclipse.equinox.registry_3.10.0.v20201107-1818.jar"
19 = "/Users/jerry/.p2/pool/plugins/org.eclipse.equinox.preferences_3.8.100.v20201102-2042.jar"
20 = "/Users/jerry/.p2/pool/plugins/org.eclipse.core.contenttype_3.7.800.v20200724-0804.jar"
21 = "/Users/jerry/.p2/pool/plugins/org.eclipse.equinox.app_1.5.0.v20200717-0620.jar"
22 = "/Users/jerry/.p2/pool/plugins/javax.annotation_1.3.5.v20200909-1856.jar"
23 = "/Users/jerry/.p2/pool/plugins/org.eclipse.swt.browser.chromium.cocoa.macosx.x86_64_3.115.100.v20201202-1103.jar"
24 = "/Users/jerry/.p2/pool/plugins/org.eclipse.swt.cocoa.macosx.x86_64_3.115.100.v20201202-1103.jar"
25 = "/Users/jerry/.m2/repository/org/xerial/sqlite-jdbc/3.32.3.2/sqlite-jdbc-3.32.3.2.jar"
26 = "/Users/jerry/.m2/repository/commons-io/commons-io/2.6/commons-io-2.6.jar"
27 = "/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar"
28 = "/Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/EclipseWorkStations/MyRcp[target/classes/]"
29 = "/Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/EclipseWorkStations/MyRcp"
30 = "/Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/EclipseWorkStations/MyRcp/libs/sqlite-jdbc-3.32.3.2.jar"

ClasspathManager 里面的 cpEntries 来自于哪里?

ClasspathManager 的创建是在 EquinoxClassLoader 里面 

我们在 ClasspathManager 里面打上断点 

... 然后我们会发现 N 个进入 ClasspathManager 的断点?, 创建了这么多的 EquinoxClassLoader ?  

我们可以稍微打印一下这些 EquinoxClassLoader 的相关上下文信息, 一些是 *.plugin.*, 另外还有一个而我们需要关注的 MyRcp 

entryLength = 31, firstBundle = /Users/jerry/EclipseWorkStations/MyRcp/target/classes

inClasspathManager - entryLength = 1, firstBundle = /Users/jerry/.p2/pool/plugins/org.eclipse.osgi_3.16.100.v20201030-1916.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.apache.felix.scr_2.1.24.v20200924-1939.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.osgi.services_3.9.0.v20200511-1725.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.equinox.common_3.14.0.v20201102-2053.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.osgi.util_3.5.300.v20190708-1141.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.core.contenttype_3.7.800.v20200724-0804.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.equinox.preferences_3.8.100.v20201102-2042.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.equinox.registry_3.10.0.v20201107-1818.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di.extensions.supplier_0.15.700.v20200622-1247.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di_1.7.600.v20200428-0912.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.core.runtime_3.20.0.v20201027-1526.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.equinox.app_1.5.0.v20200717-0620.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.equinox.event_1.5.500.v20200616-0800.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench.swt_0.15.0.v20201103-0952.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.jface_3.22.0.v20201106-0834.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.model.workbench_2.1.900.v20201014-0742.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.services_2.2.500.v20200928-2213.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench_1.12.0.v20201119-1132.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.contexts_1.8.400.v20191217-1710.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.swt_3.115.100.v20201202-1103.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.services_1.4.0.v20201014-0944.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/javax.inject_1.0.0.v20091030.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di.annotations_1.6.600.v20191216-2352.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/javax.annotation_1.3.5.v20200909-1856.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.emf.ecore_2.23.0.v20200630-0516.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.emf.common_2.21.0.v20200917-1439.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.emf.ecore.xmi_2.16.0.v20190528-0725.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.emf.ecore.change_2.14.0.v20190528-0725.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.emf.xpath_0.2.800.v20200609-0849.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.emf.databinding_1.5.0.v20180706-1146.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench.renderers.swt_0.15.0.v20201125-0918.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench.addons.swt_1.4.0.v20201119-1132.jar
 inClasspathManager - entryLength = 31, firstBundle = /Users/jerry/EclipseWorkStations/MyRcp/target/classes
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.core.commands_3.9.800.v20201021-1339.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.core.databinding.observable_1.10.0.v20200730-0848.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.jface.databinding_1.12.100.v20201014-0742.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.di_1.2.900.v20201021-1339.jar
org.sqlite.JDBC
E4LifeCycle.postContextCreate
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.commands_0.13.0.v20201119-1132.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.bindings_0.13.0.v20201119-1132.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.core.di.extensions_0.16.0.v20200507-0938.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.css.core_0.13.0.v20201015-0653.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.css.swt.theme_0.13.0.v20201026-1147.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.css.swt_0.14.0.v20201103-0952.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.w3c.css.sac_1.3.1.v200903091627.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.apache.batik.css_1.13.0.v20200622-2037.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.apache.batik.i18n_1.13.0.v20200622-2037.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.apache.batik.util_1.13.0.v20200622-2037.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.widgets_1.2.800.v20201021-1339.jar
 inClasspathManager - entryLength = 1, firstBundle = /Applications/Eclipse.app/Contents/Eclipse/../../../../Users/jerry/.p2/pool/plugins/org.eclipse.e4.ui.workbench3_0.15.500.v20201021-1339.jar

这些 module 来自于 /Users/jerry/EclipseWorkStations/.metadata/.plugins/org.eclipse.pde.core/MyRcp.product/org.eclipse.osgi/framework.info.8 解析出来的 module 部分的信息 

这个文件里面包含了 一些常规信息, 版本, 时间, 权限信息, 以及这里的 模块的相关信息, 具体的过程可以参见  Storage.<init> 

回到主题, 我们这里需要关注的是 MyRcp 对应的这个 EquinoxClassLoader 

读取 MyRcp 对应的额 classpath 读取出来的数据大致如下, 看起来就是 dev.properties 里面的配置 

配置的加载来自于 初始化 EquinoxConfiguration 的时候, 配置文件来自于 osgi.dev 的配置 

这个 osgi.dev 的配置 来自于参入的 程序参数[Program arguments]

扩展

现在能够反向的理解 使用 maven 来管理 rcp 项目的依赖 了么?

至于我最开始怎么知道修改 dev.properties 的? 你猜 ~ little tricks[占位符] 

完 

参照

使用 maven 来管理 rcp 项目的依赖