java 经典程序三道

1、异常的题目

    

public class ExceptionTest {



public static boolean a() {

try {

throw new Exception();

} catch (Exception e) {

return false;

//System.out.println(e);

} finally {

System.out.println("aaa");

}

}



public static int b() {

int i=1;

try {

throw new Exception();

} catch (Exception e) {

return i;

//System.out.println(e);

} finally {

i++;

}

}



public static int c() {

int i=1;

try {

//throw new Exception();

return 1;

} catch (Exception e) {

//System.out.println(e);

} finally {

return 2;

}

}





/**

* 功能：

* 用户：李扬

* 时间：2011-10-31

* 参数：@param args

* 返回值：void

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

System.out.println(a());

System.out.println(b());

System.out.println(c());

}

}



2、构造方法：

    

class ConstractionTest {



public static void main(String[] args){

new A();

}       

}

class A {

{     System.out.print("A");

}

static {     

    new B(1);       

}

static B b1 = new B();      

A() {     

        this(1);

System.out.print("B");

}       

A(int i) {

System.out.print("C");

}

}



class B {

static {

System.out.print("D");

}

B() {

this(1);

System.out.print("E");

}

B(int i) {

System.out.print("F");

new A();

}

}

   

3、静态代码块、静态变量

    

public class StaticTest {

public static void main(String[] args) {

System.out.println(StaticTest.country);

System.out.println(StaticTest.province);

}

static{

country = "美国";

}

private static String country = "中国";



private static String province = "山东";

static{

province = "北京";

}

}