Programming Forums > Application Development > Java

fahlyn · Jan 11th, 2008, 3:08 PM

Here is my situation: I currently get a very large xml file each month that contains data that I need to parse and load into a database. I just finished a very complex system to handle the data in this file, however I've run into a problem.

The problem is that I'm forced to open the file twice. There is a date in the header of the file that I need to grab and look at before I know if I want to parse the file. Currently, I'm using Dom4j to parse the file. I'm setting a callback handler to trigger when it finds my date node. What I'd like to be able to do is stop the parser once I find the date node. Currently, I've got this code:

(Toggle Plain Text)

	public void handleEffectiveDate() {
		reader.addHandler("/Package/PackageHeader/AsOfDate", 
			new ElementHandler(){
				public void onStart(ElementPath path){}
				public void onEnd(ElementPath path){
					Element asOfDate = path.getCurrent();
					String[] date = asOfDate.getStringValue().split("-");
					((DataWarehouse32Assembler)getBatchUploadProcesser().getAssembler()).setUploadEffectiveDate(Integer.parseInt(date[0]), Integer.parseInt(date[1]), Integer.parseInt(date[2]));
					System.out.println("Data Effective Date saved in assembler!");
					//there can be only one, like the highlander, so once you find it stop looking
					reader.removeHandler("/Package/PackageHeader/AsOfDate");
					asOfDate.detach();
				}
			}
		);
	}

I was hoping that by removing the only handler the parser would stop, however it very obviously does not.

Any recommendations?

null_ptr0 · Jan 11th, 2008, 4:12 PM

XStream and Properties.load()

fahlyn · Jan 11th, 2008, 9:20 PM

How in the world would that help me?

Dameon · Jan 11th, 2008, 9:46 PM

I'm not sure that reading only part of a document is an intended use of Dom4j. You might try throwing an exception and catching it where you call the method to begin parsing. This is just a shot in the dark.

null_ptr0 · Jan 11th, 2008, 9:59 PM

Quote:

Originally Posted by Dameon

I'm not sure that reading only part of a document is an intended use of Dom4j. You might try throwing an exception and catching it where you call the method to begin parsing. This is just a shot in the dark.

I DON'T think throwing errors as a kind of event-handling mechanism is a good thing for the jvm, or anything.

Dameon · Jan 11th, 2008, 11:10 PM

It's ugly, but might work. I wouldn't think that one exception per undesirable file is a serious performance concern, either. There simply doesn't seem to be a clean or official way to go about it.

fahlyn · Jan 12th, 2008, 7:41 AM

I was able to figure out a solution. What I'm doing is the date event handler validates that the file is one that I want to process, if it is then I set the additional event handlers, if not, i just kill the process.

its ugly, i know, but i'd much rather just kill the job than let it run and do nothing for another half hour.

Using Dom4j it takes only a few seconds to get the date and kill the job if I determine that the file shouldn't be processed. When I determine that the file should be processed it takes about 6 minutes to process the entire 1.2 gig file.

I'm still a huge fan of Dom4j.

fahlyn · Jan 12th, 2008, 7:43 AM

I am still curious to know what null_ptr0 is talking about with XStream and Properties.load(). I don't see how that is relevant to this at all.

null_ptr0 · Jan 16th, 2008, 5:01 PM

Quote:

Originally Posted by fahlyn

I am still curious to know what null_ptr0 is talking about with XStream and Properties.load(). I don't see how that is relevant to this at all.

They load from XML.

fahlyn · Jan 17th, 2008, 6:09 PM

that still doesn't make sense. A lot of things "load from XML"...but whatever...i've got my solution.

Jan 11th, 2008, 3:08 PM	#1
fahlyn Newbie Join Date: Nov 2007 Posts: 15 Rep Power: 0	Help Parsing 1.2 Gig XML File Here is my situation: I currently get a very large xml file each month that contains data that I need to parse and load into a database. I just finished a very complex system to handle the data in this file, however I've run into a problem. The problem is that I'm forced to open the file twice. There is a date in the header of the file that I need to grab and look at before I know if I want to parse the file. Currently, I'm using Dom4j to parse the file. I'm setting a callback handler to trigger when it finds my date node. What I'd like to be able to do is stop the parser once I find the date node. Currently, I've got this code: (Toggle Plain Text) public void handleEffectiveDate() { reader.addHandler("/Package/PackageHeader/AsOfDate", new ElementHandler(){ public void onStart(ElementPath path){} public void onEnd(ElementPath path){ Element asOfDate = path.getCurrent(); String[] date = asOfDate.getStringValue().split("-"); ((DataWarehouse32Assembler)getBatchUploadProcesser().getAssembler()).setUploadEffectiveDate(Integer.parseInt(date[0]), Integer.parseInt(date[1]), Integer.parseInt(date[2])); System.out.println("Data Effective Date saved in assembler!"); //there can be only one, like the highlander, so once you find it stop looking reader.removeHandler("/Package/PackageHeader/AsOfDate"); asOfDate.detach(); } } ); } public void handleEffectiveDate() { reader.addHandler("/Package/PackageHeader/AsOfDate", new ElementHandler(){ public void onStart(ElementPath path){} public void onEnd(ElementPath path){ Element asOfDate = path.getCurrent(); String[] date = asOfDate.getStringValue().split("-"); ((DataWarehouse32Assembler)getBatchUploadProcesser().getAssembler()).setUploadEffectiveDate(Integer.parseInt(date[0]), Integer.parseInt(date[1]), Integer.parseInt(date[2])); System.out.println("Data Effective Date saved in assembler!"); //there can be only one, like the highlander, so once you find it stop looking reader.removeHandler("/Package/PackageHeader/AsOfDate"); asOfDate.detach(); } } ); } I was hoping that by removing the only handler the parser would stop, however it very obviously does not. Any recommendations?

Jan 11th, 2008, 4:12 PM	#2
null_ptr0 11 years old Join Date: Nov 2007 Posts: 79 Rep Power: 1	Re: Help Parsing 1.2 Gig XML File XStream and Properties.load() __________________ iload_0 iconst_1 ishl or iload_0 iconst_2 idiv or iload_0 iconst_2 iconst_1 imul idiv [1] & [2] use the smallest stack size

Jan 11th, 2008, 9:20 PM	#3
fahlyn Newbie Join Date: Nov 2007 Posts: 15 Rep Power: 0	Re: Help Parsing 1.2 Gig XML File How in the world would that help me?

Jan 11th, 2008, 9:46 PM	#4
Dameon Troll Join Date: Apr 2005 Location: Texas Posts: 732 Rep Power: 4	Re: Help Parsing 1.2 Gig XML File I'm not sure that reading only part of a document is an intended use of Dom4j. You might try throwing an exception and catching it where you call the method to begin parsing. This is just a shot in the dark. __________________ MD5(sig) = bcef75433db02e9ad9bf81d6f7c5c270

Jan 11th, 2008, 11:10 PM	#6
Dameon Troll Join Date: Apr 2005 Location: Texas Posts: 732 Rep Power: 4	Re: Help Parsing 1.2 Gig XML File It's ugly, but might work. I wouldn't think that one exception per undesirable file is a serious performance concern, either. There simply doesn't seem to be a clean or official way to go about it. __________________ MD5(sig) = bcef75433db02e9ad9bf81d6f7c5c270

Jan 12th, 2008, 7:41 AM	#7
fahlyn Newbie Join Date: Nov 2007 Posts: 15 Rep Power: 0	Re: Help Parsing 1.2 Gig XML File I was able to figure out a solution. What I'm doing is the date event handler validates that the file is one that I want to process, if it is then I set the additional event handlers, if not, i just kill the process. its ugly, i know, but i'd much rather just kill the job than let it run and do nothing for another half hour. Using Dom4j it takes only a few seconds to get the date and kill the job if I determine that the file shouldn't be processed. When I determine that the file should be processed it takes about 6 minutes to process the entire 1.2 gig file. I'm still a huge fan of Dom4j.

Jan 12th, 2008, 7:43 AM	#8
fahlyn Newbie Join Date: Nov 2007 Posts: 15 Rep Power: 0	Re: Help Parsing 1.2 Gig XML File I am still curious to know what null_ptr0 is talking about with XStream and Properties.load(). I don't see how that is relevant to this at all.

Jan 17th, 2008, 6:09 PM	#10
fahlyn Newbie Join Date: Nov 2007 Posts: 15 Rep Power: 0	Re: Help Parsing 1.2 Gig XML File that still doesn't make sense. A lot of things "load from XML"...but whatever...i've got my solution.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
parsing xml file using tinyxml!!	honeybee	XML	2	Dec 28th, 2006 11:39 PM
Parsing File	mr_noname	Community Announcements and Feedback	1	Jul 21st, 2005 8:13 AM
.lst File Help needed / Parsing	JamesLomuscio	C++	1	Mar 10th, 2005 5:16 PM
After execution - Error cannot locate /Skin File?	wchar	Visual Basic	1	Mar 5th, 2005 9:04 PM
airport Log program using 3D linked List : problem reading from file	gemini_shooter	C++	0	Mar 2nd, 2005 4:12 PM

Programming Forums > Application Development > Java

Help Parsing 1.2 Gig XML File