构造方法传参数的小心得

Shape类中

import java.awt.Color;
import java.awt.Graphics;

/*
 * 顶级形状类
 */

public abstract class  Shape {
	//坐标
	public int x1,x2,y1,y2;
	//颜色
	public Color color;
	//构造方法
	public Shape(int x1,int y1,int x2,int y2,Color color){		this.x1=x1;
		this.y1=y1;
		this.x2=x2;
		this.y2=y2;
		this.color=color;
	}
	//抽象画图方法
	public abstract void draw(Graphics g);
	
	

}

//构造方法
public Shape(int x1,int y1,int x2,int y2,Color color){ this.x1=x1;
this.y1=y1;
this.x2=x2;
this.y2=y2;
this.color=color;
}

MyMouseListener类中

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

/*
 * 自定义鼠标监听类，继承MouseAdapter（或实现了MouseListener、MouseMotionListener）
 */

	public class MyMouseListener extends MouseAdapter{
		private int x1,y1,x2,y2;
		private Graphics g;
		private ToolPanel tool_panel;
		private ColorPanel color_panel;
		private Color color;
		private String command;
		//构造方法
		public MyMouseListener(ToolPanel tool_panel,ColorPanel color_panel,DrawPanel draw_panel){
		g=draw_panel.getGraphics();//获取画布
		this.tool_panel=tool_panel;//接收对象
		this.color_panel=color_panel;//接收对象
		
		}
		//按下
		public void mousePressed(MouseEvent e){
			x1=e.getX();
			y1=e.getY();
			command=tool_panel.getCommand();//获取标志
			color=color_panel.getColor();//获取颜色
			g.setColor(color);//设置画布的颜色
		
		}
		//释放
		public void mouseReleased(MouseEvent e){
		x2=e.getX();
		y2=e.getY();
		
		if("line".equals(command)){
			Line line=new Line(x1,y1,x2,y2,color);			line.draw(g);
		
		}
		else if("rect".equals(command)){
			Rect rect=new Rect(x1,y1,x2,y2,color);			rect.draw(g);
		}
		else if("oval".equals(command)){
			Oval oval=new Oval(x1,y1,x2,y2,color);			oval.draw(g);
		}
		
		
	}
		//拖拽
		public void mouseDragged(MouseEvent e){
			x2=e.getX();
			y2=e.getY();
			Line line=new Line(x1,y1,x2,y2,color);
			line.draw(g);
			x1=x2;
			y1=y2;
		}

}

if("line".equals(command)){
Line line=new Line(x1,y1,x2,y2,color); line.draw(g);

}
else if("rect".equals(command)){
Rect rect=new Rect(x1,y1,x2,y2,color); rect.draw(g);
}
else if("oval".equals(command)){
Oval oval=new Oval(x1,y1,x2,y2,color); oval.draw(g);
}

Line类中

import java.awt.Color;
import java.awt.Graphics;

public class Line extends Shape{
	//构造方法
	public Line(int x1,int y1,int x2,int y2,Color color){
		super(x1,y1,x2,y2,color);//调用父类的构造方法
	}
	//实现抽象画图方法    画直线
	public void draw(Graphics g){
		g.setColor(color);
		g.drawLine(x1,y1,x2,y2);
	}

}

//构造方法
public Line(int x1,int y1,int x2,int y2,Color color){
super(x1,y1,x2,y2,color);//调用父类的构造方法
}

Rect类中

import java.awt.Color;
import java.awt.Graphics;

public class Rect extends Shape{
	//构造方法
	public Rect(int x1,int y1,int x2,int y2,Color color){
		super(x1,y1,x2,y2,color);
	}
	//实现父类的抽象方法
	public void draw(Graphics g){
		g.setColor(color);
		g.drawRect(Math.min(x1,x2), Math.min(y1, y2), Math.abs(x1-x2), Math.abs(y1-y2));
	}

}

public Rect(int x1,int y1,int x2,int y2,Color color){
super(x1,y1,x2,y2,color);Oval类中

import java.awt.Color;
import java.awt.Graphics;

public class Oval extends Shape{
	//构造方法
	public Oval(int x1,int y1,int x2,int y2,Color color){
		super(x1,y1,x2,y2,color);//调用直接父类的构造方法
		
		
	}
	//实现抽象方法类       画椭圆
	public void draw(Graphics g){
		g.setColor(color);
		g.drawOval(Math.min(x1,x2),Math.min(y1,y2),Math.abs(x1-x2),Math.abs(y2-y2));
		
	}
}

//构造方法
public Oval(int x1,int y1,int x2,int y2,Color color){
super(x1,y1,x2,y2,color);//调用直接父类的构造方法


}


这几个类中的构造方法中的参数的传参顺序：MyMouseListener类中的x1,y1,x2,y2,color 传到Line类，Rect类，Oval类中的构造方法中，然后，传到Shape类中的构造方法中。