java 異常抛出 throw 與 return

package 異常;

public class TestException {
    public TestException() {
    }

    boolean testEx() throws Exception {
        boolean ret = true;
        try {
            ret = testEx1();
        } catch (Exception e) {
           e.printStackTrace();
            System.out.println("testEx, catch exception");
            ret = false;
            throw e;
        } finally {
            System.out.println("testEx, finally; return value=" + ret);
            return ret;
        }
    }

    boolean testEx1() throws Exception {
        boolean ret = true;
        try {
            ret = testEx2();
            if (!ret) {
                return false;
            }
            System.out.println("testEx1, at the end of try");
            return ret;
        } catch (Exception e) {
           e.printStackTrace();
            System.out.println("testEx1, catch exception");
            ret = false;
            throw e;
        } finally {
            System.out.println("testEx1, finally; return value=" + ret);
            return ret;
        }
    }

    boolean testEx2() throws Exception {
        boolean ret = true;
        try {
            int b = 12;
            int c;
            for (int i = 2; i >= -2; i--) {
                c = b / i;
                System.out.println("i=" + i);
            }
//            return true;
        } catch (Exception e) {
           e.printStackTrace();
            System.out.println("testEx2, catch exception");
            ret = false;
           //極其重要 throw 可以代替 return 若後面 finally 中是 return 調用此方法的將不會收到異常
           //（即catch裏面作爲結果抛出的異常被finally裏面的return覆蓋了）   若沒有return也沒有抛出某異常則調用的將會接到此處抛出的異常並處理
            throw e;
        } finally {
            System.out.println("testEx2, finally; return value=" + ret);
//            return ret;
            throw new ArrayIndexOutOfBoundsException();
        }
//        System.out.println("執行中");
//        return false;
    }

    public static void main(String[] args) {
        TestException testException1 = new TestException();
        try {
            testException1.testEx();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("main");
        }
    }
}

結果

i=2
i=1
java.lang.ArithmeticException: / by zero
   at 異常.TestException.testEx2(TestException.java:48)
   at 異常.TestException.testEx1(TestException.java:25)
   at 異常.TestException.testEx(TestException.java:10)
   at 異常.TestException.main(TestException.java:71)
testEx2, catch exception
testEx2, finally; return value=false
java.lang.ArrayIndexOutOfBoundsException
   at 異常.TestException.testEx2(TestException.java:62)
   at 異常.TestException.testEx1(TestException.java:25)
   at 異常.TestException.testEx(TestException.java:10)
   at 異常.TestException.main(TestException.java:71)
testEx1, catch exception
testEx1, finally; return value=false
testEx, finally; return value=false