Java获取配置文件的属性值通用工具类2

最近用Junit对SpringMVC做单元测试的时候，报Failed to load ApplicationContext错误。网上很多资料都说报这个错误是因为Spring的配置文件没有加载，可是实际上我已经全部加载，最后断点调试才发现是因为没有获取到配置文件中的属性值。这里就涉及到我上一篇获取配置文件中的属性值，有兴趣的同学可以回头看看。

首先，我们来看看，我之前是怎么获取到配置文件的路径的，这里还是以conf.properties为例。

	public static String getWebRoot() {
		ClassLoader classLoader = Thread.currentThread()
				.getContextClassLoader();
		URL url = classLoader.getResource("/");
		String filepath = url.getPath();
		filepath = filepath.substring(0, filepath.lastIndexOf("/"));
		filepath = filepath.substring(0, filepath.lastIndexOf("/"));
		filepath = filepath.substring(0, filepath.lastIndexOf("/"));
		log.info("filepath------" + filepath);
		return filepath;
	}

不在tomcat环境下启动时，URL url = classLoader.getResource("/");这句代码中获取到的url的值为null。这里我有个疑惑，类在编译成功后就被类装载器加载了的，为什么这里会出现url的值为null的情况，知道的同学还望不吝赐教。于是，我就在网上找到另外一种获取配置文件路径的方法。

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.commons.configuration.AbstractConfiguration;

import com.netflix.config.ConfigurationManager;

public class ConfigUtils {

    private static ConfigUtils instance = null;

    private static AbstractConfiguration config;
    
    private ConfigUtils() {
      
    }

    private static void loadConfig() {
        InputStream in = null;
        try {
            Properties prop = new Properties();
            in = IOStream.getResourceStream("conf.properties");
            prop.load(in);
            config = ConfigurationManager.getConfigInstance();
        } catch (IOException e) {
            throw new RuntimeException("load config error!", e);
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Throwable t) {
            }
        }
    }
    
    public static ConfigUtils instance() {
        if (instance == null) {
            synchronized (ConfigUtils.class) {
                if (instance == null) {
                    loadConfig();
                    instance = new ConfigUtils();
                }
            }
        }
        return instance;
    }

    public String getString(String key, String defValue) {
        return config.getString(key, defValue);
    }

    public long getLong(String key) {
        return config.getLong(key, 0);
    }

    public int getInt(String key) {
        return config.getInt(key, 0);
    }

    public int getInt(String key, int defaultValue) {
        return config.getInt(key, defaultValue);
    }

    public boolean getBoolean(String key) {
        return config.getBoolean(key, false);
    }

    public String getString(String key) {
        return getString(key, null);
    }
}

IOStream类

import java.io.InputStream;
import java.net.URL;

public class IOStream {

    private IOStream() {

    }

    public static InputStream getResourceStream(String name) {
        InputStream is = IOStream.class.getResourceAsStream(name);
        if (is == null) {
            is = IOStream.class.getClassLoader().getResourceAsStream(name);
        }

        if (is == null) {
            is = Thread.currentThread().getContextClassLoader().getResourceAsStream(name);
        }
        return is;
    }

    public static URL getResource(String name) {

        URL url = Thread.currentThread().getContextClassLoader().getResource(name);

        if (url == null) {
            url = IOStream.class.getClassLoader().getResource(name);
        }
        if (url == null) {
            url = IOStream.class.getResource(name);
        }

        return url;
    }
}

把代码中涉及到的获取conf.properties中某个属性值的方法修改一下。

	private final static String REV_SERVERHOST = ConfigUtils.instance()
			.getString("receivemail.serverHost");

于是就这样完美的解决了我的问题，后续有时间补上junit对SpringMVC的单元测试代码。补充一点，这种方式需要引入jar包。

	<dependency>
            <groupId>com.netflix.archaius</groupId>
            <artifactId>archaius-core</artifactId>
            <version>0.7.5</version>
        </dependency>