1.
用interface
來定義系統對外提供的服務，有抽象類來做擴展。盡量用interface
作為參數類型。
2. ThreadLocal類，定義了一個變量的本地副本，與原有變量隔離，作用類似static變量，只是不共享。可用set添加變量，get去獲取變量。變量類型不限制。
3. Eclipse plug in開發中可以實現IRuntimeClasspathProvider接口。可以提供用launch configuration去獲得unresolved和resolved classpath。開發人員可以在resolveClasspath方法中加入自定義的classpath。實現類需要注冊在extension point中。
/**
*Computesandreturnsanunresolvedclasspathforthegivenlaunchconfiguration.
*Variableandcontainerentriesarenotresolved.
*
*@paramconfigurationlaunchconfiguration
*@returnunresolvedpath
*@exceptionCoreExceptionifunabletocomputeapath
*/
public IRuntimeClasspathEntry[] computeUnresolvedClasspath(ILaunchConfiguration configuration) throws CoreException;
/**
*Returnstheresolvedpathcorrespondingtothegivenpath,inthecontextofthe
*givenlaunchconfiguration.Variableandcontainerentriesareresolved.Thereturned
*(resolved)pathneednothavethesamenumberofentriesasthegiven(unresolved)
*path.
*
*@paramentriesentriestoresolve
*@paramconfigurationlaunchconfigurationcontexttoresolvein
*@returnresolvedpath
*@exceptionCoreExceptionifunabletoresolveapath
*/
public IRuntimeClasspathEntry[] resolveClasspath(IRuntimeClasspathEntry[] entries, ILaunchConfiguration configuration) throws CoreException;
A provider extension is defined in plugin.xml. Following is an example definition of a runtime classpath provider extension.
<extension point="org.eclipse.jdt.launching.classpathProviders">
<classpathProvider
id="com.example.ExampleClasspathProvider"
class="com.example.ExampleClasspathProviderImpl"
</classpathProvider>
</extension>
4. plug in 開發中可以用JavaRuntime 去得到運行環境的信息。
IRuntimeClasspathProvider provider = JavaRuntime.getClasspathProvider(configuration);
其中configuration是ILaunchConfiguration類型的。
4. 在Eclipse plug in開發中獲取文件。兩種解決辦法：1.從plug in實例中讀取文件的URL，然后用FileLocator把這個URL轉化成文件路徑；2.直接利用FileLocator的find方法。
方法1
//filepath 是需要定位的文件
String filepath = "/bin/resources/test.jar";
//instance 是當前plug in的實例
URL url = instance.getBundle().getEntry(filepath);
String path = null;
try {
path = FileLocator.resolve(url).getPath();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
returnnew Path(path);
}
方法2
String filepath = "/bin/resources/test.jar";
URL url = FileLocator.find(instance.getBundle(),new Path(filepath),null);
try {
path = FileLocator.resolve(url).getPath();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
5. 可以利用JarOutputStream來寫jar包。必須為JarOutputStream 實例創建至少一個Entry，可以調用putNextEntry方法。
Manifest mf = new Manifest();
JarOutputStream jar = new JarOutputStream(new FileOutputStream("MainTest.jar")，mf);
Properties properties = new Properties();
jar.putNextEntry(new ZipEntry("MainTest.property"));
properties.store(jar, "this is a test");
jar.close();
6. 得到IJavaModle
IJavaModel model = JavaCore.create(ResourcesPlugin.getWorkspace()
.getRoot());
IJavaProject[] projects = model.getJavaProjects();
IPackageFragmentRoot[] roots = projects[i] .getPackageFragmentRoots();
然后可以依次得到對應elements