Ngrinder 源码之Maven 项目

Ngrinder支持Maven结构的测试脚本。使用ScriptHandlerFactory来个脚本选择处理器handler，目前有JythonScriptHandler， GroovyScriptHandler和GroovyMavenProjectHandler三种。 ScriptHandlerFactory初始化的时候会按各个handler的order和displayOrder排序（升序）。

	public void init() {
		// Sort by the order of scriptHandlers..
		Collections.sort(scriptHandlers, new Comparator<ScriptHandler>() {
			@Override
			public int compare(ScriptHandler o1, ScriptHandler o2) {
				return o1.order().compareTo(o2.order());
			}
		});
 
		// Sort by the order of scriptHandlers..
 
		visibleHandlers = newArrayList();
		for (ScriptHandler each : this.scriptHandlers) {
			if (!(each instanceof NullScriptHandler)) {
				visibleHandlers.add(each);
			}
		}
		Collections.sort(visibleHandlers, new Comparator<ScriptHandler>() {
			@Override
			public int compare(ScriptHandler o1, ScriptHandler o2) {
				return o1.displayOrder().compareTo(o2.displayOrder());
			}
		});
 
	}
然后选择handler的时候按order升序，找到第一个canHandler为true的处理器返回。

	public ScriptHandler getHandler(FileEntry fileEntry) {
		for (ScriptHandler handler : scriptHandlers) {
			if (handler.canHandle(fileEntry)) {
				return handler;
			}
		}
		// Actually nothing is reach here.
		throw processException("no matching handler for " + fileEntry.getPath());
	}

MavenScriptProjectHandler 判断canhandle就是看根目录下有没有.pom文件

return getFileEntryRepository().hasOne(fileEntry.getCreatedUser(), getBasePath(path) + "/pom.xml");

Maven项目运行时，maven里面依赖的包会自动拷贝到./lib文件夹下

	@Override
	protected void prepareDistMore(Long testId, User user, FileEntry script, File distDir,
	                               PropertiesWrapper properties, ProcessingResultPrintStream processingResult) {
		String pomPathInSVN = PathUtils.join(getBasePath(script), "pom.xml");
		MavenCli cli = new MavenCli();
		processingResult.println("\nCopy dependencies by running 'mvn dependency:copy-dependencies"
				+ " -DoutputDirectory=./lib -DexcludeScope=provided'");
 
		int result = cli.doMain(new String[]{ // goal specification
				"dependency:copy-dependencies", // run dependency goal
				"-DoutputDirectory=./lib", // to the lib folder
				"-DexcludeScope=provided" // but exclude the provided
				// library
		}, distDir.getAbsolutePath(), processingResult, processingResult);
		boolean success = (result == 0);
		if (success) {
			processingResult.printf("\nDependencies in %s was copied.\n", pomPathInSVN);
			LOGGER.info("Dependencies in {} is copied into {}/lib folder", pomPathInSVN, distDir.getAbsolutePath());
		} else {
			processingResult.printf("\nDependencies copy in %s is failed.\n", pomPathInSVN);
			LOGGER.info("Dependencies copy in {} is failed.", pomPathInSVN);
		}
		// Then it's not necessary to include pom.xml anymore.
		FileUtils.deleteQuietly(new File(distDir, "pom.xml"));
		processingResult.setSuccess(result == 0);
	}

这里有两个注意的地方。

1. Ngrinder使用MavenCli来运行maven命令，所以跟本机的maven环境不一样，如果有特殊的maven setting要配置的话要手动给maven指定setting.xml的位置。

public static final File DEFAULT_GLOBAL_SETTINGS_FILE =
        new File( System.getProperty( "maven.home", System.getProperty( "user.dir", "" ) ), "conf/settings.xml" );

ngrinder通过获取环境变量maven.home来查找setting.xml， 可以启动的时候加参数-Dmaven.home=xxxxx来指定maven 的配置。

2. Ngrinder会把pom文件里面的provided scope的依赖包自动过滤掉，所以对于一些会导致包冲突的artifact可以用scope来exclude掉。