Catching Multiple Exceptions in Java

The catch clause specifies the types of exceptions that the block can handle, and each exception type is separated with a vertical bar (|).

try {
    // ...
} catch (IOException | SQLException ex) {
    logger.log(ex);
    throw ex;
}

NOTE: An exception can not be a subtype or supertype of one of the catch clause's exception parameters, otherwise code will not compile:

try (DataOutputStream out = new DataOutputStream(new FileOutputStream("data"))) {
    out.writeUTF("Hello");
} catch (FileNotFoundException | IOException  e) { // COMPILATION FAILS !!!
    // ...
}

NOTE: If a catch block handles more than one exception type, then the catch parameter is implicitly final. In this example, the catch parameter ex is final and therefore you cannot assign any values to it within the catch block:

try (DataOutputStream out = new DataOutputStream(new FileOutputStream("data"))) {
    out.writeUTF("Hello");
} catch (RuntimeException | IOException  e) {
    e = new Exception(); // COMPILATION FAILS !!! (The e is final)
}

Bytecode generated by compiling a catch block that handles multiple exception types will be smaller (and thus superior) than compiling many catch blocks that handle only one exception type each. A catch block that handles multiple exception types creates no duplication in the bytecode generated by the compiler; the bytecode has no replication of exception handlers.