We have some code written using commons-httpclient-3.1 that needs to be converted to 4.1. I'm only somewhat familiar with this and am reading the 4.1 httpclient tutorial now.
I see a couple of posts here (e.g. Converting from HttpClient 3 to 4 but that's about a specific construct). Seems like there should be some docs/examples somewhere showing how to upgrade usage of 3.x to 4.x ?
One specific example: replacing use of org.apache.commons.httpclient.HttpState
I would replace the library jar(s) in your IDE and look for compiler errors to start with. You may wish to go back and check all usages to ensure they are used the same way, and parameters remain as expected (hopefully they didn't switch things around).
Is there a specific piece of code you are unsure how to get working with 4.1?
来源：https://stackoverflow.com/questions/6615394/migrating-from-httpclient-3-x-to-4-x