try finally 执行顺序
class Exc{ int a; int b; } public class Except { @SuppressWarnings("finally") static int compute (){ Exc e = new Exc(); e.a = 10; e.b = 10; int res = 0 ; try{ res = e.a / e.b; System.out.println("try ……"); return res + 1; }catch(NullPointerException e1){ System.out.println("NullPointerException occured"); }catch(ArithmeticException e1){ System.out.println("ArithmeticException occured"); }catch(Exception e3){ System.out.println("Exception occured"); }finally{ System.out.println("finnaly occured"); } System.out.println(res); return res+3; } public static void main(String[] args){ int b = compute(); System.out.println("mian b= "+b); } }
输出:
try ……
finnaly occured
mian b= 2
结论: 如果没有异常, 则执行try 中的代码块,直到 try 中的 return,接着执行 finally 中的代码块,finally 执行完后 , 回到try 中执行 return 。退出函数。
class Exc{ int a; int b; } public class Except { @SuppressWarnings("finally") static int compute (){ Exc e = new Exc(); // e.a = 10; // e.b = 10; int res = 0 ; try{ res = e.a / e.b; System.out.println("try ……"); return res + 1; }catch(NullPointerException e1){ System.out.println("NullPointerException occured"); }catch(ArithmeticException e1){ System.out.println("ArithmeticException occured"); }catch(Exception e3){ System.out.println("Exception occured"); }finally{ System.out.println("finnaly occured"); } System.out.println(res); return res+3; } public static void main(String[] args){ int b = compute(); System.out.println("mian b= "+b); } }
输出:
ArithmeticException occured
finnaly occured
0
mian b= 3
结论: 如果try 中有异常, 则在异常语句处,跳转到catch 捕获的异常代码块, 执行完 catch 后,再执行 finally ,跳出 try{}catch{}finally{} ,继续向下执行,不会去执行try中 后面的语句。
public class Test2 { public static void main(String [] args){ System.out.println(com()); } @SuppressWarnings("finally") static boolean com(){ try{ return true; }finally{ return false; } } }
输出 false
public class Test3 { public static void main(String[] args){ try{ System.out.println("try……"); System.exit(0); }finally{ System.out.println("finally……"); } } }
输出:
try…… 程序退出,不执行 finally