Configuration Hadoop配置属性返回Null
我编写了一个简单的代码来测试如何在Hadoop中设置配置Configuration Hadoop配置属性返回Null,configuration,hadoop,configuration-files,Configuration,Hadoop,Configuration Files,我编写了一个简单的代码来测试如何在Hadoop中设置配置 public static void main(String[] args) { Configuration conf = new Configuration(); conf.addResource("~/conf.xml"); System.out.println(conf); System.out.println(conf.get("color")); } 上述程序的
public static void main(String[] args) {
Configuration conf = new Configuration();
conf.addResource("~/conf.xml");
System.out.println(conf);
System.out.println(conf.get("color"));
}
上述程序的输出为:
Configuration: core-default.xml, core-site.xml, ~/conf.xml
null
因此,conf.get(“color”)
返回null
。但是,我在conf.xml
中明确设置了该属性,如下所示:
<property>
<name>color</name>
<value>yellow</value>
<description>Color</description>
</property>
颜色
黄色的
颜色
需要将资源添加为URL,否则该字符串将被解释为类路径资源(目前无法解析且被忽略-我知道您认为警告消息会转储到某个地方):
谢谢你的回答。实际上,
conf.addResource(新路径(“”)
也可以工作。
/**
* Add a configuration resource.
*
* The properties of this resource will override properties of previously
* added resources, unless they were marked <a href="#Final">final</a>.
*
* @param name resource to be added, the classpath is examined for a file
* with that name.
*/
public void addResource(String name) {
addResourceObject(name);
}
@Test
public void testConf() throws MalformedURLException {
Configuration conf = new Configuration();
conf.addResource(new File("~/conf.xml")
.getAbsoluteFile().toURI().toURL());
conf.reloadConfiguration();
System.err.println(conf);
System.err.println(conf.get("color"));
}