How to throw again IOException in java? [duplicate]

问题

This question already has answers here:

how to throw an IOException? (7 answers)

Closed 6 years ago.

Code:

 catch (IOException e) {
        LOGGER.error("IOException exception happened");
        //now need throw again the same exception to be 
                       //catched in    the    upper method
    }

But when I try simply:

  catch (IOException e) {
        LOGGER.error("IOException exception happened");
        //now need throw again the same exception to be 
                       //catched in    the    upper method
               throw e;
    }

Eclipse supposes to me put "throw e" in try catch block. But this is nonsense. How fix this problem? Thanks.

回答1:

Since IOException is a checked exception, that method needs to be declared as throwing IOException if you want it to propagate. For example:

void myMethod() throws IOException {
    try {
        //code
    }
    catch(IOException e) {
        LOGGER.error("IOException exception happened");
        throw e;
    }
}

回答2:

The second code fragment is just fine. Just remember that You have to declare Your method as:

public void myMethod() throws IOException {
    ...
}

回答3:

Try adding throws IOException to your method, e.g.:

private void yourMethodName() throws IOException {
    # your method
}

Then Eclipse won't ask for the second try catch block.

来源：https://stackoverflow.com/questions/11209885/how-to-throw-again-ioexception-in-java