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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="http://www.mamicode.com/+ 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="http://www.mamicode.com/+ 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="http://www.mamicode.com/+ 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=http://www.mamicode.com/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=http://www.mamicode.com/false
testEx, finally; return value=http://www.mamicode.com/false
質料 http://www.cnblogs.com/to-creat/p/5688235.html
java 異常抛出 throw 與 return