package c06;
import com.bruceeckel.simpletest.*;
import java.util.*;class Shape {
Shape(int i) {
System.out.println("Shape constructor");
}
void dispose() {
System.out.println("Shape dispose");
}
}class Circle extends Shape {
Circle(int i) {
super(i);
System.out.println("Drawing Circle");
}
void dispose() {
System.out.println("Erasing Circle");
super.dispose();
}
}class Triangle extends Shape {
Triangle(int i) {
super(i);
System.out.println("Drawing Triangle");
}
void dispose() {
System.out.println("Erasing Triangle");
super.dispose();
}
}class Line extends Shape {
private int start, end;
Line(int start, int end) {
super(start);
this.start = start;
this.end = end;
System.out.println("Drawing Line: "+ start+ ", "+ end);
}
void dispose() {
System.out.println("Erasing Line: "+ start+ ", "+ end);
super.dispose();
}
}public class CADSystem extends Shape {
private static Test monitor = new Test();
private Circle c;
private Triangle t;
private Line[] lines = new Line[5];
public CADSystem(int i) {
super(i + 1);
for(int j = 0; j < lines.length; j++)
lines[j] = new Line(j, j*j);
c = new Circle(1);
t = new Triangle(1);
System.out.println("Combined constructor");
}
public void dispose() {
System.out.println("CADSystem.dispose()");
// The order of cleanup is the reverse
// of the order of initialization
t.dispose();
c.dispose();
for(int i = lines.length - 1; i >= 0; i--)
lines[i].dispose();
super.dispose();
}
public static void main(String[] args) {
CADSystem x = new CADSystem(47);
try {
// Code and exception handling...
} finally {
x.dispose();
}
monitor.expect(new String[] {
"Shape constructor",
"Shape constructor",
"Drawing Line: 0, 0",
"Shape constructor",
"Drawing Line: 1, 1",
"Shape constructor",
"Drawing Line: 2, 4",
"Shape constructor",
"Drawing Line: 3, 9",
"Shape constructor",
"Drawing Line: 4, 16",
"Shape constructor",
"Drawing Circle",
"Shape constructor",
"Drawing Triangle",
"Combined constructor",
"CADSystem.dispose()",
"Erasing Triangle",
"Shape dispose",
"Erasing Circle",
"Shape dispose",
"Erasing Line: 4, 16",
"Shape dispose",
"Erasing Line: 3, 9",
"Shape dispose",
"Erasing Line: 2, 4",
"Shape dispose",
"Erasing Line: 1, 1",
"Shape dispose",
"Erasing Line: 0, 0",
"Shape dispose",
"Shape dispose"
});
}
} ///:~这里的for(int j = 0; j < lines.length; j++)
lines[j] = new Line(j, j*j);
怎么理解?
import com.bruceeckel.simpletest.*;
import java.util.*;class Shape {
Shape(int i) {
System.out.println("Shape constructor");
}
void dispose() {
System.out.println("Shape dispose");
}
}class Circle extends Shape {
Circle(int i) {
super(i);
System.out.println("Drawing Circle");
}
void dispose() {
System.out.println("Erasing Circle");
super.dispose();
}
}class Triangle extends Shape {
Triangle(int i) {
super(i);
System.out.println("Drawing Triangle");
}
void dispose() {
System.out.println("Erasing Triangle");
super.dispose();
}
}class Line extends Shape {
private int start, end;
Line(int start, int end) {
super(start);
this.start = start;
this.end = end;
System.out.println("Drawing Line: "+ start+ ", "+ end);
}
void dispose() {
System.out.println("Erasing Line: "+ start+ ", "+ end);
super.dispose();
}
}public class CADSystem extends Shape {
private static Test monitor = new Test();
private Circle c;
private Triangle t;
private Line[] lines = new Line[5];
public CADSystem(int i) {
super(i + 1);
for(int j = 0; j < lines.length; j++)
lines[j] = new Line(j, j*j);
c = new Circle(1);
t = new Triangle(1);
System.out.println("Combined constructor");
}
public void dispose() {
System.out.println("CADSystem.dispose()");
// The order of cleanup is the reverse
// of the order of initialization
t.dispose();
c.dispose();
for(int i = lines.length - 1; i >= 0; i--)
lines[i].dispose();
super.dispose();
}
public static void main(String[] args) {
CADSystem x = new CADSystem(47);
try {
// Code and exception handling...
} finally {
x.dispose();
}
monitor.expect(new String[] {
"Shape constructor",
"Shape constructor",
"Drawing Line: 0, 0",
"Shape constructor",
"Drawing Line: 1, 1",
"Shape constructor",
"Drawing Line: 2, 4",
"Shape constructor",
"Drawing Line: 3, 9",
"Shape constructor",
"Drawing Line: 4, 16",
"Shape constructor",
"Drawing Circle",
"Shape constructor",
"Drawing Triangle",
"Combined constructor",
"CADSystem.dispose()",
"Erasing Triangle",
"Shape dispose",
"Erasing Circle",
"Shape dispose",
"Erasing Line: 4, 16",
"Shape dispose",
"Erasing Line: 3, 9",
"Shape dispose",
"Erasing Line: 2, 4",
"Shape dispose",
"Erasing Line: 1, 1",
"Shape dispose",
"Erasing Line: 0, 0",
"Shape dispose",
"Shape dispose"
});
}
} ///:~这里的for(int j = 0; j < lines.length; j++)
lines[j] = new Line(j, j*j);
怎么理解?
解决方案 »
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