Configuration Property
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Properties;
import java.util.ResourceBundle;
public abstract class PropertyLoader {
/**
* Looks up a resource named 'name' in the classpath. The resource must map
* to a file with .properties extension. The name is assumed to be absolute
* and can use either "/" or "." for package segment separation with an
* optional leading "/" and optional ".properties" suffix. Thus, the
* following names refer to the same resource:
*
* <pre>
* some.pkg.Resource
* some.pkg.Resource.properties
* some/pkg/Resource
* some/pkg/Resource.properties
* /some/pkg/Resource
* /some/pkg/Resource.properties
* </pre>
*
* @param name
* classpath resource name [may not be null]
* @param loader
* classloader through which to load the resource [null is
* equivalent to the application loader]
*
* @return resource converted to java.util.Properties [may be null if the
* resource was not found and THROW_ON_LOAD_FAILURE is false]
* @throws IllegalArgumentException
* if the resource was not found and THROW_ON_LOAD_FAILURE is
* true
*/
private static final boolean THROW_ON_LOAD_FAILURE = true;
private static final boolean LOAD_AS_RESOURCE_BUNDLE = false;
private static final String SUFFIX = ".properties";
public static Properties loadProperties(String name, ClassLoader loader) {
if (name == null)
throw new IllegalArgumentException("null input: name");
if (name.startsWith("/"))
name = name.substring(1);
if (name.endsWith(SUFFIX))
name = name.substring(0, name.length() - SUFFIX.length());
Properties result = null;
InputStream in = null;
try {
if (loader == null)
loader = ClassLoader.getSystemClassLoader();
if (LOAD_AS_RESOURCE_BUNDLE) {
name = name.replace('/', '.');
// throws MissingResourceException on lookup failures:
final ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault(), loader);
result = new Properties();
for (Enumeration keys = rb.getKeys(); keys.hasMoreElements();) {
final String key = (String) keys.nextElement();
final String value = rb.getString(key);
result.put(key, value);
}
} else {
name = name.replace('.', '/');
if (!name.endsWith(SUFFIX))
name = name.concat(SUFFIX);
// returns null on lookup failures:
in = loader.getResourceAsStream(name);
if (in != null) {
result = new Properties();
result.load(in); // can throw IOException
}
}
} catch (Exception e) {
result = null;
} finally {
if (in != null)
try {
in.close();
} catch (Throwable ignore) {
}
}
if (THROW_ON_LOAD_FAILURE && (result == null)) {
throw new IllegalArgumentException("could not load [" + name + "]" + " as "
+ (LOAD_AS_RESOURCE_BUNDLE ? "a resource bundle" : "a classloader resource"));
}
return result;
}
/**
* A convenience overload of {@link #loadProperties(String, ClassLoader)}
* that uses the current thread's context classloader.
*/
public static Properties loadProperties(final String name) {
return loadProperties(name, Thread.currentThread().getContextClassLoader());
}
private PropertyLoader() {
} // this class is not extensible
}
System.out.println(new File(".").getAbsolutePath());