The Java TM programming language in the Java SE 7 platform has been enhanced with a range of features to improve productivity and flexibility.This Java SE 7 Edition of The Java TM Programming Language Specification fully describes these features.In additon,it integrates all the changes made to the Java programming language under maintenance since the publication of the Third Edition in 2005.
总结一下子：基于Java SE 7平台的Java语言已经在一系列功能上面进行了增强，以提高产品性能和灵活性。当前版本的说明书，全面阐述和描述了这些功能。此外，本书整合了自2005年第三版以来Java语言在维护中所发生的所有改变。
The majority of new features in this editon were specified by JSR-334:Small Enhancements to the Java Progarmming Language ,led by Joe Darcy with an Expert Group of Joshua Bloch,Bruch Chapman,Alexey Kudravtsev,Mark ,xxx...The origins of these features lie in Project Coin,an OpenJDK project created in 2009 with the goal of "Making things programmers do every day easier" .The project solicited proposals from the Java community for broadly useful language features that were,in comparison with "large" features like generics,relatively "small" in their specification,implementation,and testing.
总结一下子：这个版本的变化的新功能主要就是JSR-334.这个新功能本身是存在于OpenJDK的工程中的。
Thousands of emails and six dozen proposals later,proposals were accepted from Joshua Bloch(the try-with-resources statement),Derek Foster/Bruce Chapman(improvements to literals),Neal Gafter(multi-catch and precise re-throw),Bob Lee(simplified variable arity method invocation),and Jeremy Manson(improved type inference for instance creation,a.k.a. the "diamond" operator).The popular "strings in switch" feature was also accepted.Special thanks are due to Tom Ball,xx,…… ，
and all those who submitted interesting proposals and thoughtful comments to Project Coin.Over the course of the project,there were essential contributions from Mandy Chung,Jon Gibbons,xxx,xxx,and xxx in areas ranging from library support to language specification.Stuart Marks led a "coinification" effort to apply the features to the Oracle JDK codebase,both to validate their utility and to develop conventions for wider use.
The "diamond" operator and precise re-throw give type inference a new visibility in the Java programming language.To a great extent,inference is worthwhile only if it produces types no less specific than those in a manifestly-typed program prior to Java SE 7.Otherwise,new code may find inference insufficient ,and migration from manifest to inferred types in existing code is risky.To mitigate the risk,Joe Darcy and XXX experimented with different inference approaches on a large corpus of open source Java code,measuring their effectiveness.Such "quantitative language design" greatly improves confidence in the suitability and safety of the final feature.The challenge of growing a mature language with millions of developers is partially offset by the ability of language designers to learn from developers' actual code.
The Java SE 7 platform adds features that cater for non-Java languages,effectively expanding the computational model of the platform.Without changes,the Java language would be unable to access or even express some of these features.The static type system of the Java language comes under particular stress when invoking code written in dynamically typed language.Consequently,method invocation in the Java language has been modified to support method handle invocation as defined by JSR-292:Dynamically Typed Languages on the Java Platform.
The JCK team whose work helps validate this specification are due an enormous vote of thanks:xxx,xxxx.
Many other colleagues at Oracle(past or present)have also given valuable support to this specification:xx,xx,and xx.
The following individuals have all provided many valuable comments which improved this specification:xx,xxx and xx.……
This edition is the first to be written in the DocBook format.Metadata in the XML markup forms a kind of static type system,classifying each paragraph by its role,such as a definition or an error.The reward is much crisper conformance testing.
Many thanks go to Robert Stayton for sharing his considerable DocBook expertise and for producing stylesheets to render DocBook in the traditional look and feel of The Java Language Specification.
Finally,15 years after publication of the first edtion of this specification,we hope you find this edition useful and informative.Long may the Java programming language be a reliable partner and trusted friend for millions of developers.
June,2011
