今天来看下怎么在程序中使用Equinox容器。
startup
上一篇文章中，我们通过下面的命令启动了容器，
> java -jar org.eclipse.osgi_3.10.2.v20150203-1939.jar -console通过查看org.eclipse.osgi_3.10.2.v20150203-1939.jar这个jar包的MANIFEST.MF找到Main-Class，
Main-Class: org.eclipse.core.runtime.adaptor.EclipseStarterEclipseStarter的main方法中有如下注释，
/**
* This is the main to start osgi.
* It only works when the framework is being jared as a single jar
*/所以不能通过main方法来启动。Google了一把，在SO上面发现有人问过这个问题，里面说到可以通过startup方法来启动，EclipseStarter.startup((new String[]{"-console"}), null);等同于上面jar包启动的方式。
EquinoxConfiguration
以编程方式启动，同样的，需要configuration/config.ini文件与org.eclipse.osgi_3.10.2.v20150203-1939.jar在同一目录下，但这只是默认的配置，可以通过设置system property来改变。
容器的配置主要都存在EquinoxConfiguration中，而关于目录这样的location配置则单独抽了出来，放在EquinoxLocations中。二者都是在EquinoxContainer中初始化，
public EquinoxContainer(Map<String, ?> configuration) {
this.equinoxConfig = new EquinoxConfiguration(configuration, new HookRegistry(this));
this.equinoxLocations = new EquinoxLocations(this.equinoxConfig);
loadConfig(equinoxConfig, equinoxLocations);
...
}EquinoxConfiguration将所有配置到保存到了一个Properties中，
private final Properties configuration;而由EquinoxContainer传入的那个Map则是initialConfig，最终也会被存到configuration当中。这个initialConfig是由EclipseStarter#getConfiguration构造出来的，
private synchronized static Map<String, String> getConfiguration() {
if (configuration == null) {
configuration = new HashMap<String, String>();
// TODO hack to set these to defaults for EclipseStarter
// Note that this hack does not allow these properties to be specified in config.ini
configuration.put(EquinoxConfiguration.PROP_USE_SYSTEM_PROPERTIES, System.getProperty(EquinoxConfiguration.PROP_USE_SYSTEM_PROPERTIES, "true")); //$NON-NLS-1$
configuration.put(EquinoxConfiguration.PROP_COMPATIBILITY_BOOTDELEGATION, System.getProperty(EquinoxConfiguration.PROP_COMPATIBILITY_BOOTDELEGATION, "true")); //$NON-NLS-1$
}
return configuration;
}注意，EquinoxConfiguration.PROP_USE_SYSTEM_PROPERTIES的配置默认是true，会将所有的system property存入EquinoxConfiguration中，
this.configuration = useSystemProperties ? System.getProperties() : new Properties();EquinoxLocations
说完EquinoxConfiguration接下来看看EquinoxLocations。EquinoxLocations会在构造函数中，使用EquinoxConfiguration，初始化各种位置信息。我们来看下config.ini的位置是怎么得出来的。
config.ini文件在EquinoxContainer#loadConfig方法中使用，
private static void loadConfig(EquinoxConfiguration equinoxConfig, EquinoxLocations equinoxLocations) {
if (Boolean.TRUE.toString().equals(equinoxConfig.getConfiguration(EquinoxConfiguration.PROP_IGNORE_USER_CONFIGURATION)))
return;
Location configArea = equinoxLocations.getConfigurationLocation();
if (configArea == null)
return;
URL location = null;
try {
location = new URL(configArea.getURL().toExternalForm() + CONFIG_FILE);
} catch (MalformedURLException e) {
// its ok. This should never happen
}
equinoxConfig.mergeConfiguration(loadProperties(location, equinoxConfig));
}所以是通过EquinoxLocations#configurationLocation来得出config.ini的具体位置。configurationLocation的计算逻辑，上面已经说了，在EquinoxLocations的构造函数中，
mungeConfigurationLocation();
// compute a default but it is very unlikely to be used since main will have computed everything
temp = buildLocation(PROP_CONFIG_AREA_DEFAULT, null, "", false, false, null); //$NON-NLS-1$
defaultLocation = temp == null ? null : temp.getURL();
if (defaultLocation == null && equinoxConfig.getConfiguration(PROP_CONFIG_AREA) == null)
// only compute the default if the configuration area property is not set
defaultLocation = buildURL(computeDefaultConfigurationLocation(), true);
configurationLocation = buildLocation(PROP_CONFIG_AREA, defaultLocation, "", false, false, null); //$NON-NLS-1$也就是说如果没有设置PROP_CONFIG_AREA，就会使用默认的配置，
private String computeDefaultConfigurationLocation() {
// 1) We store the config state relative to the ‘eclipse‘ directory if possible
// 2) If this directory is read-only
// we store the state in <user.home>/.eclipse/<application-id>_<version> where <user.home>
// is unique for each local user, and <application-id> is the one
// defined in .eclipseproduct marker file. If .eclipseproduct does not
// exist, use "eclipse" as the application-id.
URL installURL = computeInstallConfigurationLocation();
if (installURL != null && "file".equals(installURL.getProtocol())) { //$NON-NLS-1$
File installDir = new File(installURL.getFile());
File defaultConfigDir = new File(installDir, CONFIG_DIR);
if (!defaultConfigDir.exists())
defaultConfigDir.mkdirs();
if (defaultConfigDir.exists() && StorageUtil.canWrite(defaultConfigDir))
return defaultConfigDir.getAbsolutePath();
}
// We can‘t write in the eclipse install dir so try for some place in the user‘s home dir
return computeDefaultUserAreaLocation(CONFIG_DIR);
} private URL computeInstallConfigurationLocation() {
String property = equinoxConfig.getConfiguration(PROP_INSTALL_AREA);
if (property != null)
return LocationHelper.buildURL(property, true);
return null;
}所以默认的配置是使用了PROP_INSTALL_AREA，而PROP_INSTALL_AREA是在EquinoxConfiguration#initializeProperties中设置的，
// initialize some framework properties that must always be set
if (getConfiguration(PROP_FRAMEWORK) == null || getConfiguration(EquinoxLocations.PROP_INSTALL_AREA) == null) {
ProtectionDomain pd = EquinoxConfiguration.class.getProtectionDomain();
CodeSource cs = pd == null ? null : pd.getCodeSource();
URL url = cs == null ? null : cs.getLocation();
if (url == null) {
IOException cause = null;
// try to determine by loading a resource we know we have
URL java6Profile = EquinoxConfiguration.class.getResource("/JavaSE-1.6.profile"); //$NON-NLS-1$
if (java6Profile != null && "jar".equals(java6Profile.getProtocol())) { //$NON-NLS-1$
try {
url = ((JarURLConnection) java6Profile.openConnection()).getJarFileURL();
} catch (IOException e) {
cause = e;
}
}
if (url == null) {
throw new IllegalArgumentException(NLS.bind(Msg.ECLIPSE_STARTUP_PROPS_NOT_SET, PROP_FRAMEWORK + ", " + EquinoxLocations.PROP_INSTALL_AREA), cause); //$NON-NLS-1$
}
}
// allow props to be preset
if (getConfiguration(PROP_FRAMEWORK) == null) {
String externalForm = getFrameworkPath(url.toExternalForm(), false);
setConfiguration(PROP_FRAMEWORK, externalForm);
}
if (getConfiguration(EquinoxLocations.PROP_INSTALL_AREA) == null) {
String filePart = getFrameworkPath(url.getFile(), true);
setConfiguration(EquinoxLocations.PROP_INSTALL_AREA, filePart);
}
}
// always decode these properties
setConfiguration(PROP_FRAMEWORK, decode(getConfiguration(PROP_FRAMEWORK)));
setConfiguration(EquinoxLocations.PROP_INSTALL_AREA, decode(getConfiguration(EquinoxLocations.PROP_INSTALL_AREA)));妥妥的，原来是使用了ProtectionDomain里面的CodeSource，关于他俩，之前有文章介绍过了。所以正如上面所说的，configuration/config.ini与org.eclipse.osgi_3.10.2.v20150203-1939.jar默认情况下需要在同一目录。这个PROP_INSTALL_AREA会被很多其他location用到，具体可以看看EquinoxLocations的构造函数。
简单起见，我直接将相关jar包及配置扔到%JAVA_HOME%/jre/lib/ext目录下了，
C:\Java\jdk1.7.0_51\jre\lib>tree ext /F
C:\JAVA\JDK1.7.0_51\JRE\LIB\EXT
│ dnsns.jar
│ jaccess.jar
│ localedata.jar
│ org.eclipse.equinox.common_3.6.200.v20130402-1505.jar
│ org.eclipse.osgi_3.10.2.v20150203-1939.jar
│ org.eclipse.update.configurator_3.3.300.v20140518-1928.jar
│ sunec.jar
│ sunjce_provider.jar
│ sunmscapi.jar
│ zipfs.jar
│
├─configuration
│ config.ini
│
└─plugins
me.kisimple.just4fun.osgi.common_1.0.0.jar
org.apache.felix.gogo.command_0.10.0.v201209301215.jar
org.apache.felix.gogo.runtime_0.10.0.v201209301036.jar
org.apache.felix.gogo.shell_0.10.0.v201212101605.jar
org.eclipse.equinox.console_1.1.0.v20140131-1639.jar接下来我们写代码来加载plugins目录下me.kisimple.just4fun.osgi.common_1.0.0.jar这个bundle里面的me.kisimple.just4fun.osgi.HelloOSGi，
package me.kisimple.just4fun.osgi;
public class HelloOSGi {
public void run() {
System.out.println("Hello,OSGi.");
}
}该bundle的MANIFEST.MF如下，
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: common
Bundle-SymbolicName: me.kisimple.just4fun.osgi.common
Bundle-Version: 1.0.0
Bundle-Vendor: KISIMPLE
Bundle-Localization: systembundle
Import-Package: org.osgi.framework
Export-Package: me.kisimple.just4fun.osgi
直接上代码，
import org.eclipse.core.runtime.adaptor.EclipseStarter;
import org.eclipse.osgi.container.ModuleWiring;
import org.eclipse.osgi.internal.framework.EquinoxBundle;
import org.eclipse.osgi.internal.loader.BundleLoader;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
public class Main {
public static void main(String[] args) throws Throwable {
// BundleContext context = EclipseStarter.startup((new String[]{"-console"}), null);
BundleContext context = EclipseStarter.startup((new String[]{}), null);
String className = "me.kisimple.just4fun.osgi.HelloOSGi";
String packageName = BundleLoader.getPackageName(className);
for (Bundle osgiBundle : context.getBundles()) {
if(osgiBundle instanceof EquinoxBundle) {
EquinoxBundle bundle = (EquinoxBundle)osgiBundle;
ModuleWiring wiring = bundle.getModule().getCurrentRevision().getWiring();
if (wiring != null) {
BundleLoader loader = (BundleLoader)wiring.getModuleLoader();
if (loader != null && loader.isExportedPackage(packageName)) {
Class<?> klass = bundle.loadClass(className);
System.out.println(klass);
System.out.println(klass.getClassLoader());
}
}
}
}
EclipseStarter.shutdown();
}
}输出如下，
class me.kisimple.just4fun.osgi.HelloOSGi
org.eclipse.osgi.internal.loader.EquinoxClassLoader@54432395[me.kisimple.just4fun.osgi.common:1.0.0(id=3)]alright，今天就到这^_^
时间： 2024-11-04 15:49:07