java - 是否finally块总是用Java执行？(Does a finally block always get executed in Java?)

Question

Considering this code, can I be absolutely sure that the finally block always executes, no matter what something() is?

(考虑到这段代码，我能绝对确定无论something()是finally块始终执行吗？)

try {  
    something();  
    return success;  
}  
catch (Exception e) {   
    return failure;  
}  
finally {  
    System.out.println("I don't know if this will get printed out");
}

  ask by jonny five translate from so

Answer 1

Yes, finally will be called after the execution of the try or catch code blocks.

(是的，在try或catch代码块执行之后， finally将被调用。)

The only times finally won't be called are:

(finally不会被调用的唯一时间是：)

1. If you invoke System.exit()

   (如果您调用System.exit())

2. If you invoke Runtime.getRuntime().halt(exitStatus)

   (如果调用Runtime.getRuntime().halt(exitStatus))

3. If the JVM crashes first

   (如果JVM首先崩溃)

4. If the JVM reaches an infinite loop (or some other non-interruptable, non-terminating statement) in the try or catch block

   (如果JVM在try或catch块中达到了无限循环（或其他不间断，不终止的语句）)

5. If the OS forcibly terminates the JVM process;

   (操作系统是否强行终止了JVM进程；)

   eg, kill -9 <pid> on UNIX

   (例如，在UNIX上kill -9 <pid>)

6. If the host system dies;

   (如果主机系统死机；)

   eg, power failure, hardware error, OS panic, et cetera

   (例如，电源故障，硬件错误，操作系统崩溃等)

7. If the finally block is going to be executed by a daemon thread and all other non-daemon threads exit before finally is called

   (如果finally块将由守护程序线程执行，并且所有其他非守护程序线程退出，则在调用finally之前)