标签：src nal exception 结果 image alt lan 技术 fbo
一，抛异常的类型
抛异常：1,Error错误，系统错误 2,Exception错误
Exception类又包括：RuntimeException非检查异常和检查异常。
Error例子: 1.AssertionError程序运行期间判断某个条件是否满足
,不满足时，抛出AssertionError。
2.OOM Error系统内存不足。
二，小探索
int i=1, j=0, k;
k=i/j;
javac生成idiv字节码指令
double d1=100,d2=0,result;
result=d1/d2;
System.out.println("浮点数除以零：" + data);
浮点数除以0：Infinity
javac生成ddiv字节码指令，JVM在具体实现这两个指令时，采用了不同的处理策略，导致两段代码运行时得到不同的结果。
三，try catch的嵌套
public class CatchWho { public static void main(String[] args) { try { try { throw new ArrayIndexOutOfBoundsException(); } catch(ArrayIndexOutOfBoundsException e) { System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch"); } throw new ArithmeticException(); } catch(ArithmeticException e) { System.out.println("发生ArithmeticException"); } catch(ArrayIndexOutOfBoundsException e) { System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch"); } } }
ArrayIndexOutOfBoundsException/内层try-catch 发生ArithmeticException
上述是结果
public class CatchWho2 { public static void main(String[] args) { try { try { throw new ArrayIndexOutOfBoundsException(); } catch(ArithmeticException e) { System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch"); } throw new ArithmeticException(); } catch(ArithmeticException e) { System.out.println("发生ArithmeticException"); } catch(ArrayIndexOutOfBoundsException e) { System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch"); } } }
ArrayIndexOutOfBoundsException/外层try-catch
看下面这段代码，
public class EmbededFinally { public static void main(String args[]) { int result; try { System.out.println("in Level 1"); try { System.out.println("in Level 2"); //result=100/0; //Level 2 try { System.out.println("in Level 3"); result=100/0; //Level 3 } catch (Exception e) { System.out.println("Level 3:" + e.getClass().toString()); } finally { System.out.println("In Level 3 finally"); } // result=100/0; //Level 2 } catch (Exception e) { System.out.println("Level 2:" + e.getClass().toString()); } finally { System.out.println("In Level 2 finally"); } // result = 100 / 0; //level 1 } catch (Exception e) { System.out.println("Level 1:" + e.getClass().toString()); } finally { System.out.println("In Level 1 finally"); } } }
运行结果为
in Level 1 in Level 2 in Level 3 Level 3:class java.lang.ArithmeticException In Level 3 finally In Level 2 finally In Level 1 finally
当有多层嵌套的finally时，异常在不同的层次抛出 ，在不同的位置抛出，会导致不同的finally语句块执行顺序。
四，自定义异常
Class MyException extends Exception
{ … }
Class MyClass {
void someMethod() {
if (条件) throw new MyException();
}
}
标签：src nal exception 结果 image alt lan 技术 fbo
原文地址：https://www.cnblogs.com/xcl666/p/9938913.html
