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Enabling assertions for Packages

 
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Hi,
What is the syntax for enabling the assertions for packages.
In K&B it has given that the syntax for enabling assertions is,
(Page No, 262 - If the package name is com.geeksanonymus)
java -ea:com.geeksanonymus <classname>
With the above syntax you can enable the assertions for all the classes in the package com.geeksanonymus and its sub packages too.
But in some material i saw the syntax is,
java -ea ... com.geeksanonymus <classname>
I am having one more doubt,
In some material i saw that, Assetion can be used for
"When you have written a comment that asserts as invariant"
What is the meaning of the above sentence....

Thanks in Advance...
 
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Hi,
There are 4 ways to Enable or Disable assertions:
1. -ea and -da. This is used to enable/disable assertions for all non-system classes.
2. -ea:<packagename>.../-da:<packagename>... - This enables/disables the assertions in the package given by the packagename & it's subpackages.
3. -ea:.../-da:... enables/disables all assertions in the unnamed package
4. -ea:<classname>/-da:<classname> - Enables/Disables all assertions in the particular class
 
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Hi,
I also have the same doubt. I think I saw this in Marcus, not sure though.
In some material i saw that, Assetion can be used for
"When you have written a comment that asserts as invariant"
What is the meaning of the above sentence....
Regards,
Raman
 
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This invarint topic is from Khalid's book. The book provides a nice explanation for this.
Cheers
-Suresh
 
Padma Raman
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Hi,
I do not have the Kahlid's book. Could you please explain it if you can?
Regards
 
Narasimha Rao B.
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Hi Swati,
I fully agree with you, that uisng the 3 dots to indicate if it is a package name instead of class name. But if you see the K&B book - Page no 263, Table 4.4 - Below is the syntax to enable assertions for com.foo
java -ea:com.foo
Here how it will work without using the dots.. This my exact doubt.

Thanks..
 
Swati Singhal
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Are they talking about the foo class within the com package??
Because -ea:com.foo (wihout the dots) will enable assertions for the foo class within com package.
 
Narasimha Rao B.
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Hi Swati,
com.foo - is package. Not foo class in com package..
Thanks
 
Greenhorn
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You can refer regarding Invariants in the below url
http://java.sun.com/j2se/1.4.2/docs/guide/lang/assert.html#usage-invariants
also the excerpt regarding Assertion from Khalid's book.
http://www.ii.uib.no/~khalid/pgjc/jcbook/JC2_Ch05-assertions-excerpt.pdf
 
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