java异常处理机制

public class TestException {
public TestException() {
}

boolean testEx() throws Exception {
boolean ret = true;
try {
ret = testEx1();
} catch (Exception e) {
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) {
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) {
System.out.println("testEx2, catch exception");
ret = false;
throw e;
} finally {
System.out.println("testEx2, finally; return value=" + ret);
return ret;
}
}

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

答案是：

i=2
i=1
testEx2, catch exception
testEx2, finally; return value=false
testEx1, finally; return value=false
testEx, finally; return value=false

原因：当你在finally中用了return语句，此时会忽略掉try和catch中的return语句和抛出的异常。

参考自：深入理解java异常处理机制