package com.wang.study;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Map;
import java.util.Properties;

public class SystemStudy {
	
	
	private static void printEnv() {
		Map<String, String>envMap=System.getenv();
		for(String key:envMap.keySet()) {
			System.out.println(key+"---------------"+envMap.get(key));
		}
	}


	private static void printProperties() {
		Properties properties=System.getProperties();
		for(Object key:properties.keySet()) {
			System.out.println(key+"---------------------"+properties.getProperty((String) key));
		}
	}


	private static void systemGC()
			throws MalformedURLException, ClassNotFoundException, InstantiationException, IllegalAccessException {
		System.out.println("------------loading....---------------");
		@SuppressWarnings("resource")
		URLClassLoader uLoader=new URLClassLoader(new URL[] {new URL("file:D:\\PersonalCodePlus\\code\\com.wang.study\\target\\classes")});
		@SuppressWarnings("unchecked")
		Class<StringStudy> clazz=(Class<StringStudy>) uLoader.loadClass("com.wang.study.StringStudy");
		System.out.println("-------"+clazz.getName()+"--------");
		StringStudy stringStudy=clazz.newInstance();
		System.out.println("-------"+stringStudy+"---------");
		Class<? extends StringStudy> studyClazz=stringStudy.getClass();
		System.out.println("-----"+studyClazz.getName()+"-----");
		stringStudy=null;
		uLoader=null;
		clazz=null;
		System.out.println("------gc-------");
		
		System.gc();
	}


	private static void systemLoad(String nativeLibrary) {
		System.load(nativeLibrary);
	}


	private static void systemOut() throws IOException {
        PrintStream out=System.out;
		System.setOut(new PrintStream(new FileOutputStream(new File("D:\\PersonalCodePlus\\code\\com.wang.study\\src\\main\\java\\res\\hello.txt"))));
		BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(System.in));
		String string=bufferedReader.readLine();
		System.out.println(string);
		System.setOut(out);
	}
}