双击eclipse安装目录下的eclipse.exe运行后，会加载同一目录下的eclipse.ini文件（对应RCP项目也是一样，在RCP的安装目录下会有一个RCPName.ini文件）：
-startupplugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar--launcher.libraryplugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.100.v20110502-productorg.eclipse.epp.package.rcp.product--launcher.defaultActionopenFile-showsplashorg.eclipse.platform--launcher.XXMaxPermSize256M-vmargs-Dosgi.requiredJavaVersion=1.5-Xms40m-Xmx512m
其中：
-startup 指定启动的入口为：安装目录下plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
会加载该jar包中的org.eclipse.equinox.launcher.Main.class类并调用其main(String)完成app的启动过程
通过一个Exception.printStackTrace()方法来看一下Eclipse的大概启动过程：
图中是打印的状态栈，从下往上就是整个Eclipse（或者说RCP程序）的加载和启动过程，一直到App的启动。
下面来通过源代码，具体说明：
从org.eclipse.equinox.launcher.Main这个类开始:
在Main这个类的main()方法中下一个断的，调试状态启动Eclipse中的RCP程序就可以跟踪这个RCP启动的过程（Eclipse的过程也是类似的，其实EclipseIDE就是一个巨型的RCP）：
public static void main(String[] args) { int result = 0; ... result = new Main().run(args); ...}然后看一下run()方法：
public int run(String[] args) { ... basicRun(args); ...}主要实现就在basicRun()方法中：protected void basicRun(String[] args) throws Exception { //记录启动启动时间 System.getProperties().put("eclipse.startTime", Long.toString(System.currentTimeMillis())); //$NON-NLS-1$ commands = args; //处理Command参数，并根据Command参数设置默认属性 String[] passThruArgs = processCommandLine(args); if (!debug) // debug can be specified as system property as well debug = System.getProperty(PROP_DEBUG) != null; setupVMProperties();//将VM参数写入到System.Properties中 processConfiguration();//加载配置信息 getInstallLocation();//获取安装路径,这里调用一下是为了确保InstallLocation被初始化 // locate boot plugin (may return -dev mode variations) URL[] bootPath = getBootPath(bootLocation);//获取启动路径列表 setupJNI(bootPath);//启动JNIBridge，加载dll类库 //检查JDK版本 if (!checkVersion(System.getProperty("java.version"), System.getProperty(PROP_REQUIRED_JAVA_VERSION))) return; //检查配置信息 if (!checkConfigurationLocation(configurationLocation)) return; setSecurityPolicy(bootPath);//设置安全策略 handleSplash(bootPath);//启动闪屏，就是Eclipse（或RCP启动时IDE打开前带有进度条的界面） beforeFwkInvocation(); invokeFramework(passThruArgs, bootPath);//加载框架(前面的工作都是辅助，这个才是加载框架的核心) }下面针对其中的几个重要方法进行说明：
processConfiguration：处理配置信息
private void processConfiguration() { URL baseConfigurationLocation = null; Properties baseConfiguration = null; //在系统的配置文件中，键值对形如： //osgi.configuration.area=file:/E:/eclipse-rcp-indigo-SR2-win32/eclipse/configuration/ if (System.getProperty(PROP_CONFIG_AREA) == null) { String baseLocation = System.getProperty(PROP_BASE_CONFIG_AREA); if (baseLocation != null) baseConfigurationLocation = buildURL(baseLocation, true); if (baseConfigurationLocation == null) try { //在并没指定参数的情况下，将会把Location指定到: 安装目录/configuration baseConfigurationLocation = new URL(getInstallLocation(), CONFIG_DIR); } catch (MalformedURLException e) { // leave baseConfigurationLocation null } //加载目录下的config.ini文件,对其文件中的键值对 配置信息 baseConfiguration = loadConfiguration(baseConfigurationLocation); ... ... } Properties configuration = baseConfiguration; if (configuration == null || !getConfigurationLocation().equals(baseConfigurationLocation)) configuration = loadConfiguration(getConfigurationLocation()); //把配置信息合并到System.getProperties()中 mergeProperties(System.getProperties(), configuration, null); ... ... config.ini文件内容（举例）
#This configuration file was written by: org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser#Sun Feb 17 13:24:53 CST 2013org.eclipse.update.reconcile=falseeclipse.p2.profile=epp.package.rcposgi.instance.area.default=@user.home/workspaceosgi.framework=file\:plugins/org.eclipse.osgi_3.7.2.v20120110-1415.jarequinox.use.ds=trueeclipse.buildId=M20120208-0800osgi.bundles=reference\:file\:org.eclipse.equinox.simpleconfigurator_1.0.200.v20110815-1438.jar@1\:startorg.eclipse.equinox.simpleconfigurator.configUrl=file\:org.eclipse.equinox.simpleconfigurator/bundles.infoeclipse.product=org.eclipse.platform.ideosgi.splashPath=platform\:/base/plugins/org.eclipse.platformosgi.framework.extensions=osgi.bundles.defaultStartLevel=4eclipse.application=org.eclipse.ui.ide.workbencheclipse.p2.data.area=@config.dir/../p2/
getInstallLocation（） 获取当前安装路径
private URL getInstallLocation() { if (installLocation != null) return installLocation; //从系统配置信息中获取安装路径，有的话就直接返回 String installArea = System.getProperty(PROP_INSTALL_AREA); if (installArea != null) { installLocation = buildURL(installArea, true); System.getProperties().put(PROP_INSTALL_AREA, installLocation.toExternalForm()); return installLocation; } //如果没有，则通过获取main类包的路径换算出安装路径 ProtectionDomain domain = Main.class.getProtectionDomain(); CodeSource source = null; URL result = null; source = domain.getCodeSource(); result = source.getLocation(); String path = decode(result.getFile()); ... ... installLocation = new URL(result.getProtocol(), result.getHost(), result.getPort(), path); return installLocation; }getBootPath（） 获取启动路径列表
protected URL[] getBootPath(String base) throws IOException { URL url = null; if (base != null) { url = buildURL(base, true); } else { // search in the root location url = getInstallLocation(); String path = new File(url.getFile(), "plugins").toString(); path = searchFor(framework, path); if (url.getProtocol().equals("file")) url = new File(path).toURL(); else url = new URL(url.getProtocol(), url.getHost(), url.getPort(), path); } //键值对，形如：osgi.framework=file:/e:/eclipse/plugins/org.eclipse.osgi_3.7.2.v20120110-1415.jar //指定osgi jar的路径 if (System.getProperty(PROP_FRAMEWORK) == null) System.getProperties().put(PROP_FRAMEWORK, url.toExternalForm()); //获取启动路径列表 URL[] result = getDevPath(url); return result; }
setupJNI（）启动JNIBridge，加载dll类库
private void setupJNI(URL[] defaultPath) { String libPath = null; /** * 获取--launcher.library的路径, 形如： * --launcher.library * plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.100.v20110502 */ if (library != null) { File lib = new File(library); if (lib.isDirectory()) { libPath = searchFor("eclipse", lib.getAbsolutePath()); //$NON-NLS-1$ } else if (lib.exists()) { libPath = lib.getAbsolutePath(); } } if (libPath == null) { /** * 根据OS、WS、Arch等信息，加载相应的本地文件(如，dll或so)。 */ //find our fragment name String fragmentOS = getOS(); String fragmentWS = getWS(); String fragmentArch = getArch(); libPath = getLibraryPath(getFragmentString(fragmentOS, fragmentWS, fragmentArch), defaultPath); if (libPath == null && ws == null) { // no ws was specified and we didn't find the default fragment, try an alternate ws String alternateWS = getAlternateWS(fragmentWS); libPath = getLibraryPath(getFragmentString(fragmentOS, alternateWS, fragmentArch), defaultPath); if (libPath != null) { System.getProperties().put(PROP_WS, alternateWS); } } } library = libPath; if (library != null) bridge = new JNIBridge(library);//并创建JNIBridge，这个还有待研究 }invokeFramework（）启动Equinox框架
private void invokeFramework(String[] passThruArgs, URL[] bootPath) throws Exception { //如果没有指定ClassLoader，默认将boot设置为OSGi框架的ClassLoader的父类 String type = System.getProperty(PROP_FRAMEWORK_PARENT_CLASSLOADER, System.getProperty(PROP_PARENT_CLASSLOADER, PARENT_CLASSLOADER_BOOT)); ClassLoader parent = null; if (PARENT_CLASSLOADER_APP.equalsIgnoreCase(type)) parent = ClassLoader.getSystemClassLoader(); else if (PARENT_CLASSLOADER_EXT.equalsIgnoreCase(type)) { ClassLoader appCL = ClassLoader.getSystemClassLoader(); if (appCL != null) parent = appCL.getParent(); } else if (PARENT_CLASSLOADER_CURRENT.equalsIgnoreCase(type)) parent = this.getClass().getClassLoader(); //生成一个Equinox框架的StartupClassLoader，（关于ClassLoader分层机制，还有待研究） URLClassLoader loader = new StartupClassLoader(bootPath, parent); //通过该ClassLoader加载org.eclipse.core.runtime.adaptor.EclipseStarter类，并调用其run方法 Class clazz = loader.loadClass(STARTER); Method method = clazz.getDeclaredMethod("run", new Class[] {String[].class, Runnable.class}); try { //将命令行参数及闪屏线程对象传递给run方法 method.invoke(clazz, new Object[] {passThruArgs, splashHandler}); } catch (InvocationTargetException e) { } }接下来看一下EclipseStarter.run()
public static Object run(String[] args, Runnable endSplashHandler) throws Exception { if (Profile.PROFILE && Profile.STARTUP) Profile.logEnter("EclipseStarter.run()", null); //$NON-NLS-1$ ... ... try { startup(args, endSplashHandler); ... ... Object obj=run(null); return obj; } catch (Throwable e) { ... ... } finally {... ...} return null; } public static BundleContext startup(String[] args, Runnable endSplashHandler) throws Exception { ... ... FrameworkProperties.initializeProperties(); processCommandLine(args); LocationManager.initializeLocations(); loadConfigurationInfo(); finalizeProperties(); if (Profile.PROFILE) Profile.initProps(); // catch any Profile properties set in eclipse.properties... adaptor = createAdaptor();//建立适配器 framework = new Framework(adaptor);//创建Equinox框架 context = framework.getBundle(0).getBundleContext(); registerFrameworkShutdownHandlers(); publishSplashScreen(endSplashHandler);// consoleMgr = ConsoleManager.startConsole(framework);//控制台启动，会有信息输出 framework.launch();//启动框架 Bundle[] startBundles = loadBasicBundles();//loading basic bundles ... ... // set the framework start level to the ultimate value. This will actually start things // running if they are persistently active. setStartLevel(getStartLevel());//StartLevel set // they should all be active by this time ensureBundlesActive(startBundles); return context; }先到这里，有空继续分析
/** * Runs the application for which the platform was started. The platform * must be running. * <p> * The given argument is passed to the application being run. If it is <code>null</code> * then the command line arguments used in starting the platform, and not consumed * by the platform code, are passed to the application as a <code>String[]</code>. * </p> * @param argument the argument passed to the application. May be <code>null</code> * @return the result of running the application * @throws Exception if anything goes wrong */ public static Object run(Object argument) throws Exception { if (Profile.PROFILE && Profile.STARTUP) Profile.logEnter("EclipseStarter.run(Object)()", null); //$NON-NLS-1$ if (!running) throw new IllegalStateException(EclipseAdaptorMsg.ECLIPSE_STARTUP_NOT_RUNNING); // if we are just initializing, do not run the application just return. if (initialize) return new Integer(0); try { if (appLauncher == null) { boolean launchDefault = Boolean.valueOf(FrameworkProperties.getProperty(PROP_APPLICATION_LAUNCHDEFAULT, "true")).booleanValue(); //$NON-NLS-1$ // create the ApplicationLauncher and register it as a service appLauncher = new EclipseAppLauncher(context, Boolean.valueOf(FrameworkProperties.getProperty(PROP_ALLOW_APPRELAUNCH)).booleanValue(), launchDefault, log); appLauncherRegistration = context.registerService(ApplicationLauncher.class.getName(), appLauncher, null); // must start the launcher AFTER service restration because this method // blocks and runs the application on the current thread. This method // will return only after the application has stopped. return appLauncher.start(argument); } return appLauncher.reStart(argument); } catch (Exception e) { if (log != null && context != null) // context can be null if OSGi failed to launch (bug 151413) logUnresolvedBundles(context.getBundles()); throw e; } }