问题
Are there any open-source libraries that all programmers should know about? I'm thinking
something general, a sort of extension to the standard java.util that contains basic functions that are useful for all kinds of application.
回答1:
Apache Commons
Log4j
Google collections
回答2:
The Spring framework is surprisingly general purpose. I started by just using it as a configuration management tool, but then realized how helpful dependency injection is when doing test-driven development. Then I slowly discovered many useful modules hidden in the corners of Spring.
回答3:
Apache's Jakarta Commons.
回答4:
The Google Collections API is pretty handy if you use lots of, well, Collections...
回答5:
It might be worth saying that the first thing to do is get to know the libraries in the newer versions of Java. A lot of ideas have worked their way back into java - java.util.concurrent, java.nio, and javax.xml
回答6:
Functional Java offers first-class function values, immutable lists/arrays, lazy/infinite streams, tuple types, either types, optional values (type-safe alternative to null). Works well in conjunction with Google Collections or the java.util collections.
It also provides handy concurrency abstractions like parallel strategies, parallel list/array functors, actor concurrency, and composable light-weight processes.
回答7:
lambdaj is a thread safe library of static methods that provides an internal DSL to manipulate collections in a pseudo-functional and statically typed way without explicitly iterating on them. It eliminates the burden to write (often poorly readable) loops while iterating over collections.
回答8:
Here is a good start. http://java-sources.org/
回答9:
Google Collections migrated to great Guava Libraries . It contains some common utilities, string matcher, splitter, joiner, IO utils etc.
回答10:
JXL for Excel workbook creation/edition. I work in a bank and the multipurpose report tool for diary work is Excel. Whatever appliction we do must import/export from/to Excel. The only fail it's that it has memory problems with large workbooks and formating it's a little obscure
回答11:
Take a look at jmate project. It contains really helpful methods for strings, collections and IO operations (for now).
Look some examples here.
回答12:
Lately I was trying to find answer to this question. I made some data analysis for this, you can find results here and here.
来源：https://stackoverflow.com/questions/64213/what-is-the-most-useful-multi-purpose-open-source-library-for-java