Java —— try-catch-finally-return的执行顺序

（a）若try中的代码出现异常，try会终止执行，程序的控制权会交由catch中的异常处理程序

（b）可有多个catch，但catch的排列要从子类到父类

情况1：try块中没有抛出异常，且try和finally块中都有return语句

代码:

public static int NoException(){   int i=10;   try{    System.out.println("i in try block is"+i);    return --i;   }catch(Exception e){    --i;    System.out.println("i in catch - form try block is"+i);    return --i;   }finally{    System.out.println("i in finally - from try or catch block is"+i);    return --i;   }  }  

执行结果：

i in try block is10
i in finally - from try or catch block is9
the method value is8

执行顺序：

执行try块，执行到return语句时，先执行return的语句，–i，但是不返回到main 方法，执行finally块，遇到finally块中的return语句，执行–i,并将值返回到main方法，这里就不会再回去返回try块中计算得到的值

情况2：try块中没有抛出异常，仅try中有return语句

代码：

public static int NoException(){      int i=10;      try{          System.out.println("i in try block is--"+i);          return --i;      }catch(Exception e){          --i;          System.out.println("i in catch - form try block is--"+i);          return --i;      }finally{          System.out.println("i in finally - from try or catch block is--"+i);          --i;          System.out.println("i in finally block is--"+i);          //return --i;      }  } 

执行结果：

i in try block is–10
i in finally - from try or catch block is–9
i in finally block is–8
the method value is–9

执行顺序：

try中执行完return的语句后，不返回，执行finally块，finally块执行结束后，返回到try块中，返回i在try块中最后的值

情况3：try块中抛出异常，且catch,finally中都有return语句

代码：

public static int WithException(){      int i=10;      try{          System.out.println("i in try block is--"+i);          i = i/0;          return --i;      }catch(Exception e){          System.out.println("i in catch - form try block is--"+i);          --i;          System.out.println("i in catch block is--"+i);          return --i;      }finally{          System.out.println("i in finally - from try or catch block is--"+i);          --i;          System.out.println("i in finally block is--"+i);          return --i;      }  }  

执行结果：

i in try block is–10
i in catch - form try block is–10
i in catch block is–9
i in finally - from try or catch block is–8
i in finally block is–7
the method value is–6

执行顺序：

抛出异常后，执行catch块，在catch块的return的–i执行完后，并不直接返回而是执行finally，因finally中有return语句，所以，执行，返回结果6

情况4，try块中抛出异常，仅catch中有return语句

执行顺序：

类似情况2，执行完finally语句后，依旧返回catch中的执行return语句后的值，而不是finally中修改的值

情况5：try和catch中都有异常，finally中无return语句

代码：

public static int CatchException(){      int i=10;      try{          System.out.println("i in try block is--"+i);          i=i/0;          return --i;      }catch(Exception e){          System.out.println("i in catch - form try block is--"+i);          int j = i/0;          return --i;      }finally{          System.out.println("i in finally - from try or catch block is--"+i);          --i;          System.out.println("i in finally block is--"+i);          //return --i;      }  }  

执行结果：

i in try block is–10
i in catch - form try block is–10
i in finally - from try or catch block is–10
i in finally block is–9
Exception in thread “main” java.lang.ArithmeticException: / by zero
at exception.ExceptionTest0123.CatchException(ExceptionTest0123.java:29)
at exception.ExceptionTest0123.main(ExceptionTest0123.java:17)

执行顺序：

在try块中出现异常，到catch中，执行到异常，到finally中执行，finally执行结束后判断发现异常，抛出

情况6：try和catch中都有异常，finally中有return语句

代码：

public static int CatchException(){      int i=10;      try{          System.out.println("i in try block is--"+i);          i=i/0;          return --i;      }catch(Exception e){          System.out.println("i in catch - form try block is--"+i);          int j = i/0;          return --i;      }finally{          System.out.println("i in finally - from try or catch block is--"+i);          --i;          System.out.println("i in finally block is--"+i);          return --i;      }  }  

执行结果：

i in try block is–10
i in catch - form try block is–10
i in finally - from try or catch block is–10
i in finally block is–9
the method value is–8

执行顺序：

try块中出现异常到catch，catch中出现异常到finally，finally中执行到return语句返回，不检查异常

转载地址：

http://blog.csdn.net/aaoxue/article/details/8535754