关于ofbiz-component.xml文件中的resource-loader

寻找文件的方式最后是通过ComponentConfig.java的getURL方法来解析的
public URL getURL(String resourceLoaderName, String location) throws ComponentException {
        ResourceLoaderInfo resourceLoaderInfo = resourceLoaderInfos.get(resourceLoaderName);
        if (resourceLoaderInfo == null) {
            throw new ComponentException("Could not find resource-loader named: " + resourceLoaderName);
        }

        if ("component".equals(resourceLoaderInfo.type) || "file".equals(resourceLoaderInfo.type)) {
//如果是<resource-loader name="main" type="component" />
            String fullLocation = getFullLocation(resourceLoaderName, location);
            URL fileUrl = UtilURL.fromFilename(fullLocation);
            if (fileUrl == null) {
                throw new ComponentException("File Resource not found: " + fullLocation);
            }
            return fileUrl;
        } else if ("classpath".equals(resourceLoaderInfo.type)) {
            String fullLocation = getFullLocation(resourceLoaderName, location);
            URL url = UtilURL.fromResource(fullLocation);
            if (url == null) {
                throw new ComponentException("Classpath Resource not found: " + fullLocation);
            }
            return url;
        } else if ("url".equals(resourceLoaderInfo.type)) {
            String fullLocation = getFullLocation(resourceLoaderName, location);
            URL url = null;
            try {
                url = FlexibleLocation.resolveLocation(location);
            } catch (java.net.MalformedURLException e) {
                throw new ComponentException("Error with malformed URL while trying to load URL resource at location [" + fullLocation + "]", e);
            }
            if (url == null) {
                throw new ComponentException("URL Resource not found: " + fullLocation);
            }
            return url;
        } else {
            throw new ComponentException("The resource-loader type is not recognized: " + resourceLoaderInfo.type);
        }
    }

其中主要是看
就是用getFullLocation(resourceLoaderName, location);方法
它做的事是判断如果类型是component，就进行rootLocation+location。而rootLocation就是组建所在路径，而location就是我们的entity-resource或者service-resource等等设置的location。
另外这个方法还有几个操作，判断是否要使用prependEnv，如果使用，会添加上prependEnv

if (UtilValidate.isNotEmpty(resourceLoaderInfo.prependEnv)) {
            String propValue = System.getProperty(resourceLoaderInfo.prependEnv);
            if (propValue == null) {
                String errMsg = "The Java environment (-Dxxx=yyy) variable with name " + resourceLoaderInfo.prependEnv + " is not set, cannot load resource.";
                Debug.logError(errMsg, module);
                throw new IllegalArgumentException(errMsg);
            }
            buf.append(propValue);
        }

//判断是否要添加prefix
        if (UtilValidate.isNotEmpty(resourceLoaderInfo.prefix)) {
            buf.append(resourceLoaderInfo.prefix);
        }
由此可以得出，resource-loader元素的完整配置是
<resource-loader name="main" type="component" prepend-env="" prefix=""/>