в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

Admin: 1 версия

2010-05-31T14:41:40Z

1 версия

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== ClassLoader: getSystemClassLoader() ==



<source lang="java">

public class Main {
public static void main(String[] args) {
ClassLoader.getSystemClassLoader().setDefaultAssertionStatus(true);
new Loaded().go();
}
}
class Loaded {
public void go() {
assert false: "Loaded.go()";
}
}

</source>



== ClassLoader: loadClass(String name) ==



<source lang="java">

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;
public class Main {
public static void main(String[] argv) throws Exception {
File file = new File("c:\\");
URL url = file.toURI().toURL();
URL[] urls = new URL[] { url };
ClassLoader cl = new URLClassLoader(urls);
Class cls = cl.loadClass("com.mycompany.MyClass");
}
}

</source>



== ClassLoader: setDefaultAssertionStatus(boolean enabled) ==



<source lang="java">

public class Main {
public static void main(String[] args) {
ClassLoader.getSystemClassLoader().setDefaultAssertionStatus(true);
new Loaded().go();
}
}
class Loaded {
public void go() {
assert false: "Loaded.go()";
}
}

</source>



== extends ClassLoader ==



<source lang="java">

import java.io.FileInputStream;
import java.io.IOException;
import java.lang.reflect.Method;
class MyClassLoader extends ClassLoader {
public Class findClass(String name) {
byte[] classData = null;
try {
FileInputStream f = new FileInputStream("C:\\" + name + ".class");
int num = f.available();
classData = new byte[num];
f.read(classData);
} catch (IOException e) {
System.out.println(e);
}
Class x = defineClass(name, classData, 0, classData.length);
return x;
}
}
public class Main {
static public void main(String args[]) throws Exception {
MyClassLoader x = new MyClassLoader();
Class c = x.loadClass(args[0]);
Class getArg1[] = { (new String[1]).getClass() };
Method m = c.getMethod("main", getArg1);
String[] my1 = { "arg1 passed", "arg2 passed" };
Object myarg1[] = { my1 };
m.invoke(null, myarg1);
}
}

</source>

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Java by API/java.lang/ClassLoader - История изменений

в 17:43, 31 мая 2010

Admin: 1 версия