As already mentioned, the performance is the same. However, user experience isn't necessarily identical. In the first case, you'll fail fast (i.e. after the first error), however if you put the try/catch block inside the loop, you can capture all the errors that would be created for a given call to the method. When parsing an array of values from strings where you expect some formatting errors, there are definitely cases where you'd like to be able to present all the errors to the user so that they don't need to try and fix them one by one.

My perspective would be try/catch blocks are necessary to insure proper exception handling, but creating such blocks has performance implications. Since, Loops contain intensive repetitive computations, it is not recommended to put try/catch blocks inside loops. Additionally, it seems where this condition occurs, it is often "Exception" or "RuntimeException" which is caught. RuntimeException being caught in code should be avoided. Again, if if you work in a big company it's essential to log that exception properly, or stop runtime exception to happen. Whole point of this description is PLEASE AVOID USING TRY-CATCH BLOCKS IN LOOPS

在你的例子中没有功能上的区别。我觉得你的第一个例子可读性更强。

性能:

try/catch结构放置的位置绝对没有性能差异。在内部，它们被实现为调用方法时创建的结构中的代码范围表。当方法执行时，try/catch结构完全不在图中，除非发生抛出，然后将错误的位置与表进行比较。

这里有一个参考:http://www.javaworld.com/javaworld/jw-01-1997/jw-01-hood.html

这张桌子在一半的地方被描述。

我把0.02美元放进去。有时，您需要在稍后的代码中添加“finally”(因为谁会在第一次就写出完美的代码呢?)在这些情况下，将try/catch放在循环之外突然变得更有意义了。例如:

try {
    for(int i = 0; i < max; i++) {
        String myString = ...;
        float myNum = Float.parseFloat(myString);
        dbConnection.update("MY_FLOATS","INDEX",i,"VALUE",myNum);
    }
} catch (NumberFormatException ex) {
    return null;
} finally {
    dbConnection.release();  // Always release DB connection, even if transaction fails.
}

因为如果出现错误，您只希望释放一次数据库连接(或选择您最喜欢的其他资源类型……)。

As long as you are aware of what you need to accomplish in the loop you could put the try catch outside the loop. But it is important to understand that the loop will then end as soon as the exception occurs and that may not always be what you want. This is actually a very common error in Java based software. People need to process a number of items, such as emptying a queue, and falsely rely on an outer try/catch statement handling all possible exceptions. They could also be handling only a specific exception inside the loop and not expect any other exception to occur. Then if an exception occurs that is not handled inside the loop then the loop will be "preemted", it ends possibly prematurely and the outer catch statement handles the exception.

如果循环在生活中扮演清空队列的角色，那么循环很可能在队列真正清空之前就结束了。非常常见的错误。