blocks|key|1280787|text|它在那里是因为程序员希望确保调用db.cleanup()，即使try块中的代码抛出异常。任何异常都不会由该块处理，但它们只会在finally块执行后向上传播。如果没有异常，finally块也将被执行。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1280788|entityMap^0|G|C|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

It's there because the programmer wanted to make sure that <code>db.cleanup()</code> is called even if the code inside the try block throws an exception. Any exceptions will not be handled by that block, but they'll only be propagated upwards after the finally block is executed. The finally block will also be executed if there was no exception.

blocks|key|1066035|text|如果您希望当前正在执行的方法仍然抛出异常，同时允许适当地清理资源，这是很有用的。下面是一个处理来自调用方法的异常的具体示例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1066036|public+void+yourOtherMethod()+{
++++try+{
++++++++yourMethod();
++++}+catch+(YourException+ex)+{
++++++++//+handle+exception
++++}
}++++

public+void+yourMethod()+throws+YourException+{
++++try+{
++++++++db.store(mydata);
++++}+finally+{
++++++++db.cleanup();
++++}
}|code-block|syntax|javascript|1066037|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is useful if you want the currently executing method to still throw the exception while allowing resources to be cleaned up appropriately. Below is a concrete example of handling the exception from a calling method.

<pre><code>public void yourOtherMethod() {
 try {
 yourMethod();
 } catch (YourException ex) {
 // handle exception
 }
} 

public void yourMethod() throws YourException {
 try {
 db.store(mydata);
 } finally {
 db.cleanup();
 }
}
</code></pre>

blocks|key|1280865|text|finally块确保即使在抛出RuntimeException+(可能是由于被调用代码中的某个错误)时，也会进行db.cleanup()调用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1280866|这也经常被用来防止过多的嵌套：|1280867|try
{
++++if+(foo)+return+false;
++++//bla+...
++++return+true;
}
finally
{
++++//clean+up
}|code-block|syntax|javascript|1280868|特别是当方法返回的点很多时，这提高了可读性，因为任何人都可以看到在每种情况下都会调用清理代码。|1280869|entityMap^0|1K|C|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|U|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|V|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

The finally block ensures that even when a RuntimeException is thrown (maybe due to some bug in the called code), the <code>db.cleanup()</code> call will be made.

This is also often used to prevent too much nesting:

<pre><code>try
{
 if (foo) return false;
 //bla ...
 return true;
}
finally
{
 //clean up
}
</code></pre>

Especially when there are many points at which the method returns, this improves readability as anyone can see the clean up code is called in every case.

blocks|key|1066154|text|代码执行此操作是为了确保数据库已关闭。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1066155|通常，这样做的方法是将所有数据库访问代码放在try块中，然后将关闭数据库的调用放在finally块中。|1066156|try...finally的工作方式意味着try块中的代码会运行，而finally块中的代码会在finishes...no发生变化时运行。|1066157|除非计算机被从墙上拽出来，否则最终将被执行。|1066158|这意味着即使调用了异常，并且该方法需要三年时间才能执行，它仍然会进入finally块，并且数据库将被关闭。|1066159|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|O|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

The code is doing it to ensure that the database is closed. 
Usually, the way you would do it is to put all your database accessing code in the try block, and then put a call to close the database in the finally block. 
The way try...finally works, means that the code in the try block is run, and the code in the finally block is run when that finishes...no matter what. 
Short of the computer being yanked from the wall, the finally will execute. 
This means that even if an exception is called, and the method takes three years to execute, it will still go in the finally block and the database will be closed.

blocks|key|1280975|text|如果try块中的任何代码可以引发检查到的异常，则它必须出现在方法签名的throws子句中。如果抛出一个未检查的异常，它就会从方法中冒泡出来。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1280976|不管是否抛出异常，finally块都会被执行。|1280977|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

If any of the code in the try block can throw a checked exception, it has to appear in the throws clause of the method signature. If an unchecked exception is thrown, it's bubbled out of the method.

The finally block is always executed, whether an exception is thrown or not.

I saw some code like this:

<pre><code> try
 {
 db.store(mydata);
 }
 finally
 {
 db.cleanup();
 }
</code></pre>

I thought <code>try</code> is supposed to have a <code>catch</code>?

Why does this code do it this way?

Does it make sense to do "try-finally" without "catch"?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我看到了一些这样的代码：    try    {        db.store(mydata);    }    finally    {        db.cleanup();    }我以为try应该有个catch为什么这段代码要这样做呢？

问做"try-finally“而不做"catch”有意义吗？
EN

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问做"try-finally“而不做"catch”有意义吗？EN