Java exception handling and log management

Handling of exceptions

1. For exception handling, one can directly handle

The second can be thrown ,

Exception/io,sql, two large classes, compiled and run-time,

And the way to handle it: You can use your own defined method, or the system's

1-2. The way you define yourself is: Class Mye extends Exception (String msg) {

Super (MSG);

}

When used, it is the IF (a>0) {throw new Mye ("A cannot be greater than 0, please check");}

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1-2 the system is: Try{}catch () {}

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If you want to throw it to someone else, it's void div (int a, int b) throws exception{}

When you call this method, you have to write the try .... or throw it,

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2. Log

1. The first is to import Log4j.properties and Log4j.jar two files into the project.

2. The specific code is to get the path,

String filepath=test.class.getresource ("\"). GetPath ();

Where to put the Propertyconfigurator (). Configure (filepath+ "log4j.properities");

or replace it with ("d:/log4j.properities"); fixed in one position

Logger Lol=null;

try{

Lol=logger.getlogger (Test.class);//The error log for that file.

Code may have an exception code

}catch () {

Lol.debug (E.getmessage ());

}

Java exception handling and log management