??Java??ClassLoader????????
???????????? ???????[ 2015/10/29 11:19:22 ] ??????????????? ???????????
????1??ClassLoader????????????????????????????????Class??ClassLoader?????????????????????JVM??????????“?????”??????Thread????getContextClassLoader()??setContextClassLoader()??????
????2??ClassLoader???????URLClassLoader????????????????????class????jar?????URL????????????????????Class??
????3??ClassLoader?и????????parent?????ClassLoader???Class???????????????parent????????Class????е???????????????????????????ClassLoader????????????????磺
import java.net.URL;
import java.net.URLClassLoader;
/**
* ???????????Class??????????parent
*/
public class OverridingClassLoader extends URLClassLoader
{
private final ClassLoader parent;
public OverridingClassLoader(URL[] urls?? ClassLoader parent)
{
super(urls?? null);
this.parent = parent;
}
@Override
public Class<?> loadClass(String name) throws ClassNotFoundException
{
try
{
return super.loadClass(name);
} catch (Exception e)
{
return parent.loadClass(name);
}
}
}
????4??JVM??????????????ж????ClassLoader??????????????????????????????????Class???????????????Class?????????????????????Щ????????磬??????????Person??Student?м?й???????????ClassLoader??????JVM????????ClassLoader???????jar?????????????Person??????????Student??????Person??????κι????instanceof??isAssignableFrom??????false??
????5????????????????Spring??Hadoop???????????Thread.currentThread().getContextClassLoader()?????ClassLoader??????????????????????????????????ClassLoader????????????Thread.currentThread().setContextClassLoader()?????ClassLoader??????Tomcat?????????????webapp??Thread.currentThread().getContextClassLoader()?????????webapp???????WebappClassLoader???????????ò??jar????webapp??????????
??????
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2023/3/23 14:23:39???д?ò??????????
2023/3/22 16:17:39????????????????????Щ??
2022/6/14 16:14:27??????????????????????????
2021/10/18 15:37:44???????????????
2021/9/17 15:19:29???·???????·
2021/9/14 15:42:25?????????????
2021/5/28 17:25:47??????APP??????????
2021/5/8 17:01:11