manifestreader.java

来自「esri的ArcGIS Server超级学习模板程序（for java）」· Java 代码 · 共 72 行

package com.esri.solutions.jitk.common.version;

import java.net.URL;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

public class ManifestReader {
	private static final Logger _logger = LogManager.getLogger(ManifestReader.class);	
	protected String _valueToRead;
	
	public ManifestReader() {
	}
	
	public void setValueToRead(String valueName) {
		_valueToRead = valueName;
	}
	
	public String getValueToRead() {
		return _valueToRead;
	}
	
	public String getImplementationVersion()  {
		final String valueName = "Implementation-Version";
		
		String val = getNamedValue(valueName);
		_logger.info("Application Version: " + val);
		
		return val;		
	}
	
	public String getValue() {
		return getNamedValue(_valueToRead);
	}
	
	@SuppressWarnings("unchecked")
	public String getNamedValue(String valueName) {
		String val = "";
		
		try {
			Class clazz = ManifestReader.class;
			 
			String classContainer = clazz.getProtectionDomain().getCodeSource().getLocation().toString();
			
			int lastIndex = classContainer.indexOf("WEB-INF");
			//String separator = System.getProperty("file.separator");
			String separator = "/";
			
			String manifestPath = classContainer.substring(0, lastIndex - 1); 
			manifestPath += separator;
			manifestPath += "META-INF";
			manifestPath += separator;
			manifestPath += "MANIFEST.MF";
			
			_logger.debug("Manifest path: " + manifestPath);
			
			URL manifestUrl = new URL(manifestPath);
			Manifest manifest = new Manifest(manifestUrl.openStream());	

			Attributes attribs = manifest.getMainAttributes();
			val = attribs.getValue(valueName);	
		} 
		catch (Exception e) {
			_logger.error("Cannot read jar-file manifest value " + valueName, e);
		}	
		
		return val;		
	}
}