利用反射模拟框架 类加载器 加载配置文件

利用反射模拟框架

！注意路径，实际应用时使用getRealPath()+程序内路径 _运算完整的路径

或者使用类加载器加载文件，但是使用类加载器是只读的。

类加载器

InputSream in = TestFramework.class.getClassLoader().getResourceAsStream(包路径+文件名)

或者：InputSream in = TestFramework.getResourceAsStream(相对自身包的路径+文件名)

config.properties:

className=java.util.HashSet

import java.io.*;

import java.util.*;

public class TestFramework {

public static void main(String[] args) {

InputStream in = null;

try {

in = new FileInputStream("config.properties");

} catch (FileNotFoundException e) {

System.out.println("文件未找到。");

e.printStackTrace();

}

Properties prop = new Properties();

try {

prop.load(in);

} catch (IOException e) {

System.out.println("载入文件出现错误。");

e.printStackTrace();

}

try {

in.close();

} catch (IOException e) {

System.out.println("文件读取结束出错。");

e.printStackTrace();

}

String className = prop.getProperty("className");

Collection collection = null;

try {

collection = (Collection)Class.forName(className).newInstance();

} catch (Exception e) {

System.out.println("创建对象失败");

e.printStackTrace();

}

Point p1 = new Point(1,1);

Point p2 = new Point(2,2);

Point p3 = new Point(1,1);

Point p4 = new Point(3,3);

collection.add(p1);

collection.add(p2);

collection.add(p3);

collection.add(p4);

System.out.println(collection.size());

}

}

public class Point {

int x ;

int y ;

public Point(int x, int y) {

this.x = x;

this.y = y;

}

@Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + x;

result = prime * result + y;

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

Point other = (Point) obj;

if (x != other.x)

return false;

if (y != other.y)

return false;

return true;

}

}