示例代码：
package test.tool.gui.dbtool.util;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import org.apache.log4j.Logger;
import test.tool.gui.dbtool.consts.Const;
public class JarLoadUtil {
private static Logger log = Logger.getLogger(JarLoadUtil.class);
private static URL lib_url = ClassLoader.getSystemClassLoader().getResource("lib");
private static URLClassLoader loader = null;
/*
* 加载lib目录下所有jar文件，并返回相应的的URLClassLoader
*/
public static URLClassLoader getURLClassLoader(){
if(loader == null){
String fileNames[] = listFileNames();
if(fileNames != null && fileNames.length > 0){
URL urls[] = new URL[fileNames.length];
for(int i = 0;i < fileNames.length;i++){
try {
urls[i] = new URL(lib_url+"/"+fileNames[i]);
} catch (MalformedURLException e) {
if("true".equals(ConfigUtil.getConfInfo().get(Const.IS_LOG)+"")){
log.error("加载lib目录下jar文件出错！",e);
}
throw new RuntimeException("加载lib目录下jar文件出错！",e);
}
}
loader = new URLClassLoader(urls);
}
}
return loader;
}
/*
* 查询lib目录下的所有文件名称
*/
private static String[] listFileNames(){
File file_directory = new File("lib");
return file.list();
}
}
使用：
URLClassLoader loader = JarLoadUtil.getURLClassLoader();
Class<?> clazz = loader.loadClass(ds.getDriverClassName());
Driver driver = (Driver)clazz.newInstance();
Properties p = new Properties();
p.put("user", ds.getUsername());
p.put("password", ds.getPwd());
Connection con = driver.connect(ds.getUrl(), p);