Java开发之——Java6的新特性

原文请参考:Java6的新特性

序

本文梳理了下java6的新特性，相对于java5而言，java6的特性显得少些，分量也不那么重，相当于java5是windows xp，java6有点像vista。

特性列表

• JSR223脚本引擎
• JSR199--Java Compiler API
• JSR269--Pluggable Annotation Processing API
• 支持JDBC4.0规范
• JAX-WS 2.0规范

JSR223脚本引擎

• 基本使用

    public class BasicScripting 
        {
              public void greet() throws ScriptException
             {
                 ScriptEngineManager manager = new ScriptEngineManager();
                //支持通过名称、文件扩展名、MIMEtype查找
                ScriptEngine engine = manager.getEngineByName("JavaScript");
                //engine = manager.getEngineByExtension("js");
                //engine = manager.getEngineByMimeType("text/javascript");
                if (engine == null) 
                    {
                       throw new RuntimeException("找不到JavaScript语言执行引擎。");
                    }
                        engine.eval("println('Hello!');");
             }
            public static void main(String[] args)
             {
                try {
                      new BasicScripting().greet();
                    } catch (ScriptException ex) 
                    {
                           Logger.getLogger(BasicScripting.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
         }
  

• 绑定上下文

    public class ScriptContextBindings extends JsScriptRunner
     {
        public void scriptContextBindings() throws ScriptException 
          {
                ScriptEngine engine = getJavaScriptEngine();
             ScriptContext context = engine.getContext();
             Bindings bindings1 = engine.createBindings();
             bindings1.put("name", "Alex");
             context.setBindings(bindings1, ScriptContext.GLOBAL_SCOPE);
             Bindings bindings2 = engine.createBindings();
             bindings2.put("name", "Bob");
                context.setBindings(bindings2, ScriptContext.ENGINE_SCOPE);
                engine.eval("println(name);");
          }
        public void useScriptContextValues() throws ScriptException 
         {
            ScriptEngine engine = getJavaScriptEngine();
            ScriptContext context = engine.getContext();
            Bindings bindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
            bindings.put("name", "Alex");
            engine.eval("println(name);");
        }
        public void attributeInBindings() throws ScriptException
         {
            ScriptEngine engine = getJavaScriptEngine();
            ScriptContext context = engine.getContext();
            context.setAttribute("name", "Alex", ScriptContext.GLOBAL_SCOPE);
                engine.eval("println(name);");
         }
        /**
         * @param args the command line arguments
         */
        public static void main(String[] args) throws ScriptException
         {
                ScriptContextBindings scb = new ScriptContextBindings();
             scb.scriptContextBindings();
             scb.useScriptContextValues();
             scb.attributeInBindings();
            }
    }
  

JSR199--Java Compiler API

public class JavaCompilerAPICompiler 
  {
     public void compile(Path src, Path output) throws IOException 
        {
            JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
            try (StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null))
                 {
                    Iterable<? extends JavaFileObject> compilationUnits = fileManager.getJavaFileObjects(src.toFile());
                    Iterable<String> options = Arrays.asList("-d", output.toString());
                    JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, null, options, null, compilationUnits);
                    boolean result = task.call();
                }
        }
  }

JSR269--Pluggable Annotation Processing API

一部分是进行注解处理的javax.annotation.processing，另一部分是对程序的静态结构进行建模的javax.lang.model

其他

• 支持JDBC4.0规范
• JAX-WS 2.0规范(包括JAXB 2.0)
• 轻量级HttpServer