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关于JDK6新特性资料
阅读量：2292 次
发布时间：2019-05-09

本文共 32781 字，大约阅读时间需要 109 分钟。

JDK6的新特性

JDK6的新特性之一_Desktop类和SystemTray类
JDK6的新特性之七_用Console开发控制台程序
JDK6的新特性之三_理解StAX
JDK6的新特性之九_CommonAnnotations
JDK6的新特性之二_使用JAXB2来实现对象与XML之间的映射
JDK6的新特性之五_轻量级HttpServer
JDK6的新特性之八_嵌入式数据库Derby
JDK6的新特性之六_插入式注解处理API
JDK6的新特性之十_Web服务元数据
JDK6的新特性之十一_更简单强大的JAX-WS
JDK6的新特性之十三_JTable的排序和过滤
JDK6的新特性之十二_脚本语言支持
JDK6的新特性之四_使用Compiler API

JDK6的新特性之一_Desktop类和SystemTray类

JDK6.0发布有段时间了，新的JDK也有不少新的特性，我去网上搜集了一下，列在下面和大家一起学习．

１．Desktop和SystemTray. 在JDK6中 ,AWT新增加了两个类:Desktop和SystemTray,前者可以用来打开系统默认浏览器浏览指定的URL,打开系统默认邮件客户端给指定的邮箱发邮件,用默认应用程序打开或编辑文件(比如,用记事本打开以txt为后缀名的文件),用系统默认的打印机打印文档;后者可以用来在系统托盘区创建一个托盘程序。

我随便找了几张图，在Tray里面都是空的，没有图,可能是图太大，有xdjm知道希望告诉我．

 

Java代码

import java.awt.AWTException;   
import java.awt.Desktop;   
import java.awt.Image;   
import java.awt.MenuItem;   
import java.awt.PopupMenu;   
import java.awt.SystemTray;   
import java.awt.Toolkit;   
import java.awt.TrayIcon;   
import java.awt.event.ActionEvent;   
import java.awt.event.ActionListener;   
import java.io.File;   
import java.io.IOException;   
import java.net.URI;   
import java.net.URISyntaxException;   
  
public class DesktopTrayTest{   
    private static Desktop desktop;   
    private static SystemTray st;   
    private static PopupMenu pm;   
       
    public static void main( String[] args ) {   
        if( Desktop.isDesktopSupported() ) {   
            desktop = Desktop.getDesktop();   
        }   
        if( SystemTray.isSupported() ) {   
            st = SystemTray.getSystemTray();   
            Image image = Toolkit.getDefaultToolkit().createImage( "" );   
            createPopupMenu();   
            TrayIcon ti = new TrayIcon( image, "Demo", pm );   
            try{   
                st.add( ti );   
            } catch( AWTException awte ) {   
                awte.printStackTrace();   
            }   
        }   
    }   
    public static void sendMail( String mail ) {   
        if( desktop != null &&   
            desktop.isSupported( Desktop.Action.MAIL ) ) {   
            try {   
                desktop.mail( new URI( mail ) );   
            } catch (IOException e) {   
                e.printStackTrace();   
            } catch (URISyntaxException e) {   
                e.printStackTrace();   
            }   
        }   
    }   
    public static void openBrowser( String url ) {   
        if( desktop != null &&   
            desktop.isSupported( Desktop.Action.BROWSE )) {   
            try {   
                desktop.browse( new URI( url ) );   
            } catch (IOException e) {   
                e.printStackTrace();   
            } catch (URISyntaxException e) {   
                e.printStackTrace();   
            }   
        }   
    }   
    public static void edit() {   
        if( desktop != null &&   
            desktop.isSupported( Desktop.Action.EDIT ) ) {   
            File file = new File( "test.txt" );   
            try {   
                if( file.exists() == false ) {   
                    file.create();   
                }   
                desktop.edit( file );   
            } catch( IOException ioe ) {   
                ioe.printStackTrace();   
            }   
        }   
    }   
    public static void createPopupMenu() {   
        pm = new PopupMenu();   
        MenuItem ob = new MenuItem( "Open url" );   
        ob.addActionListener( new ActionListener() {   
            public void actionPerformed( ActionEvent ae ) {   
                openBrowser( "" );   
            }   
        });   
        MenuItem sm = new MenuItem( "Send Mail" );   
        sm.addActionListener( new ActionListener() {   
            public void actionPerformed( ActionEvent ae ) {   
                sendMail( "" );   
            }   
        });   
        MenuItem ed = new MenuItem( "Edit" );   
        ed.addActionListener( new ActionListener() {   
            public void actionPerformed( ActionEvent ae ) {   
                edit();   
            }   
        });   
        MenuItem ex = new MenuItem( "Exit" );   
        ex.addActionListener( new ActionListener() {   
            public void actionPerformed( ActionEvent ae ) {   
                System.exit( 0 );   
            }   
        });   
        pm.add( ob );   
        pm.add( sm );   
        pm.add( ed );   
        pm.addSeparator();   
        pm.add( ex );   
    }   
}  
import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

public class DesktopTrayTest{

    private static Desktop desktop;
    private static SystemTray st;
    private static PopupMenu pm;
   
    public static void main( String[] args ) {
        if( Desktop.isDesktopSupported() ) {
            desktop = Desktop.getDesktop();
        }
        if( SystemTray.isSupported() ) {
            st = SystemTray.getSystemTray();
            Image image = Toolkit.getDefaultToolkit().createImage( "" );
            createPopupMenu();
            TrayIcon ti = new TrayIcon( image, "Demo", pm );
            try{
                st.add( ti );
            } catch( AWTException awte ) {
                awte.printStackTrace();
            }
        }
    }
    public static void sendMail( String mail ) {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.MAIL ) ) {
            try {
                desktop.mail( new URI( mail ) );
            } catch (IOException e) {
                e.printStackTrace();
            } catch (URISyntaxException e) {
                e.printStackTrace();
            }
        }
    }
    public static void openBrowser( String url ) {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.BROWSE )) {
            try {
                desktop.browse( new URI( url ) );
            } catch (IOException e) {
                e.printStackTrace();
            } catch (URISyntaxException e) {
                e.printStackTrace();
            }
        }
    }
    public static void edit() {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.EDIT ) ) {
            File file = new File( "test.txt" );
            try {
                if( file.exists() == false ) {
                    file.create();
                }
                desktop.edit( file );
            } catch( IOException ioe ) {
                ioe.printStackTrace();
            }
        }
    }
    public static void createPopupMenu() {
        pm = new PopupMenu();
        MenuItem ob = new MenuItem( "Open url" );
        ob.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                openBrowser( "" );
            }
        });
        MenuItem sm = new MenuItem( "Send Mail" );
        sm.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                sendMail( "" );
            }
        });
        MenuItem ed = new MenuItem( "Edit" );
        ed.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                edit();
            }
        });
        MenuItem ex = new MenuItem( "Exit" );
        ex.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                System.exit( 0 );
            }
        });
        pm.add( ob );
        pm.add( sm );
        pm.add( ed );
        pm.addSeparator();
        pm.add( ex );
    }
}

２．Console. JDK6中提供了java.io.Console类专用来访问基于字符的控制台设备. 你的程序如果要与Windows下的cmd或者Linux下的Terminal交互,就可以用Console类代劳. 但我们不总是能得到可用的Console, 一个JVM是否有可用的Console依赖于底层平台和JVM如何被调用. 如果JVM是在交互式命令行(比如Windows的cmd)中启动的,并且输入输出没有重定向到另外的地方,那么就可以得到一个可用的Console实例. 下面代码演示了Console类的用法:

Java代码

import java.io.Console;   
  
public class ConsoleTest {   
    public static void main( String[] args ) {   
        Console console = System.console();   
        if( console != null ) {   
            String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );   
            String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));   
            console.printf( "User name is:%s", new Object[]{user} );   
            console.printf( "Password is:%s", new Object[]{pwd} );   
        } else {   
            System.out.println( "No Console!" );   
        }   
    }   
}  
import java.io.Console;

public class ConsoleTest {

    public static void main( String[] args ) {
        Console console = System.console();
        if( console != null ) {
            String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );
            String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));
            console.printf( "User name is:%s", new Object[]{user} );
            console.printf( "Password is:%s", new Object[]{pwd} );
        } else {
            System.out.println( "No Console!" );
        }
    }
}

你如果是在一个IDE中如eclipse, netbeans中运行你将得到：

No Console!
因为只有在命令行中才能得到Console对象。

３．Compiler API. 现在我们可以用JDK6 的Compiler API(JSR 199)去动态编译Java源文件，Compiler API结合反射功能就可以实现动态的产生Java代码并编译执行这些代码，有点动态语言的特征。这个特性对于某些需要用到动态编译的应用程序相当有用，比如JSP Web Server，当我们手动修改JSP后，是不希望需要重启Web Server才可以看到效果的，这时候我们就可以用Compiler API来实现动态编译JSP文件，当然，现在的JSP Web Server也是支持JSP热部署的，现在的JSP Web Server通过在运行期间通过Runtime.exec或ProcessBuilder来调用javac来编译代码，这种方式需要我们产生另一个进程去做编译工作，不够优雅而且容易使代码依赖与特定的操作系统；Compiler API通过一套易用的标准的API提供了更加丰富的方式去做动态编译,而且是跨平台的。 下面代码演示了Compiler API的使用：

Java代码

import java.io.BufferedWriter;   
import java.io.FileWriter;   
import java.io.IOException;   
import java.util.Iterator;   
  
import javax.tools.JavaCompiler;   
import javax.tools.JavaFileObject;   
import javax.tools.StandardJavaFileManager;   
import javax.tools.ToolProvider;   
  
public class CompilerAPITest {   
    private final static String srcFileName = "Test.java";   
    private final static String classFileName = "Test.class";   
    private final static String className = "Test";   
       
    public static void main( String[] args ) {   
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();   
        if( compiler == null ) {   
            System.err.println( "Compiler is null!" );   
            return;   
        }   
        StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );   
        generateJavaClass();   
           
        Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );   
        compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();   
        try {   
            fileManager.close();   
            Class.forName( className ).newInstance();   
        } catch (IOException e) {   
            e.printStackTrace();   
        } catch (InstantiationException e) {   
            e.printStackTrace();   
        } catch (IllegalAccessException e) {   
            e.printStackTrace();   
        } catch (ClassNotFoundException e) {   
            e.printStackTrace();   
        }   
    }   
       
    public static void generateJavaClass() {   
        try {   
            FileWriter rw = new FileWriter( srcFileName );   
            BufferedWriter bw = new BufferedWriter( rw );   
            bw.write( "public class " + className + " {" );   
            bw.newLine();   
               
            bw.write( "public " + className + "() {");   
            bw.newLine();   
            bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );   
            bw.write( "}" );   
            bw.newLine();   
               
            bw.write( "}" );   
            bw.flush();   
            bw.close();   
        } catch (IOException e) {   
            e.printStackTrace();   
        }   
    }   
}  
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

public class CompilerAPITest {

    private final static String srcFileName = "Test.java";
    private final static String classFileName = "Test.class";
    private final static String className = "Test";
   
    public static void main( String[] args ) {
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        if( compiler == null ) {
            System.err.println( "Compiler is null!" );
            return;
        }
        StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );
        generateJavaClass();
       
        Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );
        compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();
        try {
            fileManager.close();
            Class.forName( className ).newInstance();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
   
    public static void generateJavaClass() {
        try {
            FileWriter rw = new FileWriter( srcFileName );
            BufferedWriter bw = new BufferedWriter( rw );
            bw.write( "public class " + className + " {" );
            bw.newLine();
           
            bw.write( "public " + className + "() {");
            bw.newLine();
            bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );
            bw.write( "}" );
            bw.newLine();
           
            bw.write( "}" );
            bw.flush();
            bw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
JDK1.6.0新特性详解与代码示例
JDK6.0发布有段时间了，新的JDK也有不少新的特性，我去网上搜集了一下，列在下面和大家一起学习．
１．Desktop和SystemTray. 在JDK6中 ,AWT新增加了两个类:Desktop和SystemTray,前者可以用来打开系统默认浏览器浏览指定的URL,打开系统默认邮件客户端给指定的邮箱发邮件,用默认应用程序打开或编辑文件(比如,用记事本打开以txt为后缀名的文件),用系统默认的打印机打印文档;后者可以用来在系统托盘区创建一个托盘程序。

我随便找了几张图，在Tray里面都是空的，没有图,可能是图太大，有xdjm知道希望告诉我．

import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

public class DesktopTrayTest {

    private static Desktop desktop;
    private static SystemTray st;
    private static PopupMenu pm;
   
    public static void main( String[] args ) {
        if( Desktop.isDesktopSupported() ) {
            desktop = Desktop.getDesktop();
        }
        if( SystemTray.isSupported() ) {
            st = SystemTray.getSystemTray();
            Image image = Toolkit.getDefaultToolkit().createImage( "" );
            createPopupMenu();
            TrayIcon ti = new TrayIcon( image, "Demo", pm );
            try{
                st.add( ti );
            } catch( AWTException awte ) {
                awte.printStackTrace();
            }
        }
    }
    public static void sendMail( String mail ) {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.MAIL ) ) {
            try {
                desktop.mail( new URI( mail ) );
            } catch (IOException e) {
                e.printStackTrace();
            } catch (URISyntaxException e) {
                e.printStackTrace();
            }
        }
    }
    public static void openBrowser( String url ) {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.BROWSE )) {
            try {
                desktop.browse( new URI( url ) );
            } catch (IOException e) {
                e.printStackTrace();
            } catch (URISyntaxException e) {
                e.printStackTrace();
            }
        }
    }
    public static void edit() {
        if( desktop != null &&
            desktop.isSupported( Desktop.Action.EDIT ) ) {
            File file = new File( "test.txt" );
            try {
                if( file.exists() == false ) {
                    file.create();
                }
                desktop.edit( file );
            } catch( IOException ioe ) {
                ioe.printStackTrace();
            }
        }
    }
    public static void createPopupMenu() {
        pm = new PopupMenu();
        MenuItem ob = new MenuItem( "Open url" );
        ob.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                openBrowser( "" );
            }
        });
        MenuItem sm = new MenuItem( "Send Mail" );
        sm.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                sendMail( "" );
            }
        });
        MenuItem ed = new MenuItem( "Edit" );
        ed.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                edit();
            }
        });
        MenuItem ex = new MenuItem( "Exit" );
        ex.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent ae ) {
                System.exit( 0 );
            }
        });
        pm.add( ob );
        pm.add( sm );
        pm.add( ed );
        pm.addSeparator();
        pm.add( ex );
    }
}

２．Console. JDK6中提供了java.io.Console类专用来访问基于字符的控制台设备. 你的程序如果要与Windows下的cmd或者Linux下的Terminal交互,就可以用Console类代劳. 但我们不总是能得到可用的Console, 一个JVM是否有可用的Console依赖于底层平台和JVM如何被调用. 如果JVM是在交互式命令行(比如Windows的cmd)中启动的,并且输入输出没有重定向到另外的地方,那么就可以得到一个可用的Console实例. 下面代码演示了Console类的用法:

import java.io.Console;

public class ConsoleTest {

    public static void main( String[] args ) {
        Console console = System.console();
        if( console != null ) {
            String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );
            String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));
            console.printf( "User name is:%s", new Object[]{user} );
            console.printf( "Password is:%s", new Object[]{pwd} );
        } else {
            System.out.println( "No Console!" );
        }
    }
}

你如果是在一个IDE中如eclipse, netbeans中运行你将得到：
No Console!
因为只有在命令行中才能得到Console对象。

３．Compiler API. 现在我们可以用JDK6 的Compiler API(JSR 199)去动态编译Java源文件，Compiler API结合反射功能就可以实现动态的产生Java代码并编译执行这些代码，有点动态语言的特征。这个特性对于某些需要用到动态编译的应用程序相当有用，比如JSP Web Server，当我们手动修改JSP后，是不希望需要重启Web Server才可以看到效果的，这时候我们就可以用Compiler API来实现动态编译JSP文件，当然，现在的JSP Web Server也是支持JSP热部署的，现在的JSP Web Server通过在运行期间通过Runtime.exec或ProcessBuilder来调用javac来编译代码，这种方式需要我们产生另一个进程去做编译工作，不够优雅而且容易使代码依赖与特定的操作系统；Compiler API通过一套易用的标准的API提供了更加丰富的方式去做动态编译,而且是跨平台的。 下面代码演示了Compiler API的使用：

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

public class CompilerAPITest {

    private final static String srcFileName = "Test.java";
    private final static String classFileName = "Test.class";
    private final static String className = "Test";
   
    public static void main( String[] args ) {
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        if( compiler == null ) {
            System.err.println( "Compiler is null!" );
            return;
        }
        StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );
        generateJavaClass();
       
        Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );
        compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();
        try {
            fileManager.close();
            Class.forName( className ).newInstance();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
   
    public static void generateJavaClass() {
        try {
            FileWriter rw = new FileWriter( srcFileName );
            BufferedWriter bw = new BufferedWriter( rw );
            bw.write( "public class " + className + " {" );
            bw.newLine();
           
            bw.write( "public " + className + "() {");
            bw.newLine();
            bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );
            bw.write( "}" );
            bw.newLine();
           
            bw.write( "}" );
            bw.flush();
            bw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

我在运行这个例子的时候发现ToolProvider.getSystemJavaCompiler得到的是NULL,后来上网一查，原来是一个Bug!链接如下：

Closed, not reproducible

那为什么我一直在reproduce阿？

4.Http Server API. JDK6提供了一个简单的Http Server API,据此我们可以构建自己的嵌入式Http Server,它支持Http和Https协议,提供了HTTP1.1的部分实现，没有被实现的那部分可以通过扩展已有的Http Server API来实现,程序员必须自己实现HttpHandler接口,HttpServer会调用HttpHandler实现类的回调方法来处理客户端请求,在这里,我们把一个Http请求和它的响应称为一个交换,包装成HttpExchange类,HttpServer负责将HttpExchange传给 HttpHandler实现类的回调方法.下面代码演示了怎样创建自己的Http Server .

Java代码
import java.io.IOException;   
import java.io.InputStream;   
import java.io.OutputStream;   
import java.net.InetSocketAddress;   
  
import com.sun.net.httpserver.HttpExchange;   
import com.sun.net.httpserver.HttpHandler;   
import com.sun.net.httpserver.HttpServer;   
  
public class HttpServerAPITest {   
    private static int count = 0;   
    public static void main( String[] args ) {   
        try {   
            HttpServer hs = HttpServer.create( new InetSocketAddress( 8888 ), 0 );   
            hs.createContext( "/", new MyHandler() );   
            hs.createContext( "/java", new MyHandler() );   
            hs.setExecutor( null );   
            hs.start();   
            System.out.println( "---begin---" );   
            System.out.println( "Listening on " + hs.getAddress() );   
        } catch( IOException ioe ) {   
            ioe.printStackTrace();   
        }   
    }   
    static class MyHandler implements HttpHandler {   
        public void handle( HttpExchange he ) throws IOException {   
            System.out.println( "Request " + count++  );   
            System.out.println( he.getHttpContext().getPath() );   
               
            InputStream is = he.getRequestBody();   
            String response = "<font color='blue'>Happy Spring Festerval</font>";   
            he.sendResponseHeaders( 200, response.length() );   
            OutputStream os = he.getResponseBody();   
            os.write( response.getBytes() );   
            os.close();   
        }   
    }   
}  
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;

import com.sun.net.httpserver.HttpExchange;

import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

public class HttpServerAPITest {

    private static int count = 0;
    public static void main( String[] args ) {
        try {
            HttpServer hs = HttpServer.create( new InetSocketAddress( 8888 ), 0 );
            hs.createContext( "/", new MyHandler() );
            hs.createContext( "/java", new MyHandler() );
            hs.setExecutor( null );
            hs.start();
            System.out.println( "---begin---" );
            System.out.println( "Listening on " + hs.getAddress() );
        } catch( IOException ioe ) {
            ioe.printStackTrace();
        }
    }
    static class MyHandler implements HttpHandler {
        public void handle( HttpExchange he ) throws IOException {
            System.out.println( "Request " + count++  );
            System.out.println( he.getHttpContext().getPath() );
           
            InputStream is = he.getRequestBody();
            String response = "<font color='blue'>Happy Spring Festerval</font>";
            he.sendResponseHeaders( 200, response.length() );
            OutputStream os = he.getResponseBody();
            os.write( response.getBytes() );
            os.close();
        }
    }
}
5.对脚本语言的支持如: ruby, groovy, javascript.
Java代码
import java.io.FileReader;   
  
import javax.script.Invocable;   
import javax.script.ScriptEngine;   
import javax.script.ScriptEngineManager;   
  
public class ScriptTest {   
    public static void main( String[] args ) {   
        ScriptEngineManager manager = new ScriptEngineManager();   
        ScriptEngine engine = manager.getEngineByName( "ECMAScript" );   
        try {   
            engine.eval( new FileReader( "C:/test.js" ) );   
            Invocable invocableEngine = (Invocable)engine;   
            Object ret = invocableEngine.invokeFunction( "test", null );   
            System.out.println( "The result is :" + (Double)ret );   
        } catch( Exception e ) {   
            e.printStackTrace();   
        }   
    }   
}   
  
test.js如下:   
  
function test(){   
    return Math.round( 11.2 );   
}  
import java.io.FileReader;

import javax.script.Invocable;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;

public class ScriptTest {

    public static void main( String[] args ) {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName( "ECMAScript" );
        try {
            engine.eval( new FileReader( "C:/test.js" ) );
            Invocable invocableEngine = (Invocable)engine;
            Object ret = invocableEngine.invokeFunction( "test", null );
            System.out.println( "The result is :" + (Double)ret );
        } catch( Exception e ) {
            e.printStackTrace();
        }
    }
}

test.js如下:

function test(){

    return Math.round( 11.2 );
}
 6.插入式注解处理API(Pluggable Annotation Processing API)，插入式注解处理API(JSR 269)提供一套标准API来处理Annotations.JSR 269用Annotation Processor在编译期间而不是运行期间处理Annotation, Annotation Processor相当于编译器的一个插件,所以称为插入式注解处理.如果Annotation Processor处理Annotation时(执行process方法)产生了新的Java代码,编译器会再调用一次Annotation Processor,如果第二次处理还有新代码产生,就会接着调用Annotation Processor,直到没有新代码产生为止.每执行一次process()方法被称为一个"round",这样整个Annotation processing过程可以看作是一个round的序列.
举个例子：们想建立一套基于Annotation的单元测试框架(如TestNG),在测试类里面用Annotation来标识测试期间需要执行的测试方法,如下所示:

Java代码

@TestMethod  
 public void testCheckName(){   
       //do something here   
 }  
@TestMethod
 public void testCheckName(){
       //do something here
 }
这时我们就可以用JSR 269提供的API来处理测试类,根据Annotation提取出需要执行的测试方法.

再举个例子: 下面我用代码演示如何来用JSR 269提供的API来处理Annotations和读取Java源文件的元数据(metadata)

Java代码

import java.util.List;   
import java.util.Map;   
import java.util.Set;   
  
import javax.annotation.processing.AbstractProcessor;   
import javax.annotation.processing.RoundEnvironment;   
import javax.annotation.processing.SupportedAnnotationTypes;   
import javax.annotation.processing.SupportedSourceVersion;   
import javax.lang.model.SourceVersion;   
import javax.lang.model.element.AnnotationMirror;   
import javax.lang.model.element.AnnotationValue;   
import javax.lang.model.element.Element;   
import javax.lang.model.element.ExecutableElement;   
import javax.lang.model.element.TypeElement;   
import javax.lang.model.util.ElementFilter;   
import javax.tools.Diagnostic.Kind;   
  
@SupportedAnnotationTypes( "ToBeTested" )   
@SupportedSourceVersion( SourceVersion.RELEASE_6 )   
public class MyAnnotationProcessor extends AbstractProcessor {   
    private void note( String msg ) {   
        processingEnv.getMessager().printMessage( Kind.NOTE, msg );   
    }   
    public boolean process( Set< ? extends TypeElement > annotations, RoundEnvironment roundEnv ) {   
        for( TypeElement te : annotations ) {   
            note( "annotation: " + te.toString() );   
        }   
        Set< ? extends Element > elements = roundEnv.getRootElements();   
        for( Element e : elements ) {   
            List< ? extends Element > enclosedElems = e.getEnclosedElements();   
            List< ? extends ExecutableElement > ees = ElementFilter.methodsIn( enclosedElems );   
            for( ExecutableElement ee : ees ) {   
                note( "Executable Element Name: " + ee.getSimpleName() );   
                List< ? extends AnnotationMirror > as = ee.getAnnotationMirrors();   
                note( " as: " + as );    
                for( AnnotationMirror am : as ){   
                    Map< ? extends ExecutableElement, ? extends AnnotationValue > map = am.getElementValues();   
                    Set< ? extends ExecutableElement > ks = map.keySet();   
                    for( ExecutableElement k : ks ) {   
                        AnnotationValue av = map.get( k );   
                        note("----"+ee.getSimpleName()+"."+k.getSimpleName()+"="+av.getValue());   
                    }   
                }   
            }   
        }   
        return false;   
    }   
}   
  
    
  
  
public class Testing {   
    @ToBeTested(group="A")   
    public void m1(){   
    }   
    @ToBeTested(group="B",owner="QQ")   
    public void m2(){   
    }       
}   
  
    
  
import java.lang.annotation.ElementType;   
import java.lang.annotation.Retention;   
import java.lang.annotation.RetentionPolicy;   
import java.lang.annotation.Target;   
  
@Retention( RetentionPolicy.RUNTIME )   
@Target( ElementType.METHOD )   
public @interface ToBeTested {   
    String owner() default "Chinajash";   
    String group();   
}  
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.annotation.processing.AbstractProcessor;

import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.ElementFilter;
import javax.tools.Diagnostic.Kind;

@SupportedAnnotationTypes( "ToBeTested" )

@SupportedSourceVersion( SourceVersion.RELEASE_6 )
public class MyAnnotationProcessor extends AbstractProcessor {
    private void note( String msg ) {
        processingEnv.getMessager().printMessage( Kind.NOTE, msg );
    }
    public boolean process( Set< ? extends TypeElement > annotations, RoundEnvironment roundEnv ) {
        for( TypeElement te : annotations ) {
            note( "annotation: " + te.toString() );
        }
        Set< ? extends Element > elements = roundEnv.getRootElements();
        for( Element e : elements ) {
            List< ? extends Element > enclosedElems = e.getEnclosedElements();
            List< ? extends ExecutableElement > ees = ElementFilter.methodsIn( enclosedElems );
            for( ExecutableElement ee : ees ) {
                note( "Executable Element Name: " + ee.getSimpleName() );
                List< ? extends AnnotationMirror > as = ee.getAnnotationMirrors();
                note( " as: " + as );
                for( AnnotationMirror am : as ){
                    Map< ? extends ExecutableElement, ? extends AnnotationValue > map = am.getElementValues();
                    Set< ? extends ExecutableElement > ks = map.keySet();
                    for( ExecutableElement k : ks ) {
                        AnnotationValue av = map.get( k );
                        note("----"+ee.getSimpleName()+"."+k.getSimpleName()+"="+av.getValue());
                    }
                }
            }
        }
        return false;
    }
}

 

public class Testing {
    @ToBeTested(group="A")
    public void m1(){
    }
    @ToBeTested(group="B",owner="QQ")
    public void m2(){
    }   
}

 

import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention( RetentionPolicy.RUNTIME )

@Target( ElementType.METHOD )
public @interface ToBeTested {
    String owner() default "Chinajash";
    String group();
}
 7.StAX. StAX是The Streaming API for XML的缩写，是继DOM(Document Object Model)和SAX(Simple API for XML)之后的又一种处理xml的api,一种利用拉模式解析(pull-parsing)XML文档的API.StAX通过提供一种基于事件迭代器(Iterator)的API让程序员去控制xml文档解析过程,程序遍历这个事件迭代器去处理每一个解析事件，解析事件可以看做是程序拉出来的，也就是程序促使解析器产生一个解析事件然后处理该事件，之后又促使解析器产生下一个解析事件，如此循环直到碰到文档结束符；SAX也是基于事件处理xml文档，但却是用推模式解析，解析器解析完整个xml文档后，才产生解析事件，然后推给程序去处理这些事件；DOM采用的方式是将整个xml文档映射到一颗内存树，这样就可以很容易地得到父节点和子结点以及兄弟节点的数据，但如果文档很大，将会严重影响性能。

下面是个例子：

Java代码
import java.io.FileNotFoundException;   
import java.io.FileOutputStream;   
  
import javax.xml.namespace.QName;   
import javax.xml.stream.XMLEventReader;   
import javax.xml.stream.XMLInputFactory;   
import javax.xml.stream.XMLOutputFactory;   
import javax.xml.stream.XMLStreamException;   
import javax.xml.stream.XMLStreamWriter;   
import javax.xml.stream.events.StartElement;   
import javax.xml.stream.events.XMLEvent;   
  
public class StaxTest {   
    public static void main( String[] arg ) throws XMLStreamException, FileNotFoundException {   
        readXMLByStAX();   
        writeXMLByStAX();   
    }   
    public static void readXMLByStAX() throws XMLStreamException, FileNotFoundException {   
        XMLInputFactory factory = XMLInputFactory.newInstance();   
        XMLEventReader  reader = factory.createXMLEventReader( StaxTest.class.getResourceAsStream( "test.xml" ) );   
        XMLEvent event;   
        StringBuffer  parsingResult = new StringBuffer();   
        while( reader.hasNext() ) {   
            event = reader.nextEvent();   
            if( event.isStartElement() ) {   
                StartElement se = event.asStartElement();   
                parsingResult.append( "<" );   
                parsingResult.append( se.getName() );   
                if( se.getName().getLocalPart().equals( "catalog" ) ) {   
                    parsingResult.append( "id="" );   
                    parsingResult.append( se.getAttributeByName( new QName( "id" ) ).getValue());   
                    parsingResult.append( """ ) ;   
                }   
                parsingResult.append( ">" );   
            } else if( event.isCharacters() ) {   
                parsingResult.append( event.asCharacters().getData() );   
            } else if( event.isEndElement() ) {   
                parsingResult.append( "</" );   
                parsingResult.append( event.asEndElement().getName() );   
                parsingResult.append( ">" );   
            }   
        }   
        System.out.println( parsingResult );   
    }   
       
    public static void writeXMLByStAX() throws XMLStreamException, FileNotFoundException {   
        XMLOutputFactory factory = XMLOutputFactory.newInstance();   
        XMLStreamWriter writer = factory.createXMLStreamWriter( new FileOutputStream( "output.xml" ) );   
        writer.writeStartDocument();   
        writer.writeCharacters( " " );   
        writer.writeComment( "testing comment" );   
        writer.writeCharacters( " " );   
        writer.writeStartElement( "catalogs" );   
        writer.writeNamespace( "myNS", "" );   
        writer.writeAttribute( "owner", "sina" );   
        writer.writeCharacters( " " );   
        writer.writeStartElement("", "catalog");   
        writer.writeAttribute("id","007");   
        writer.writeCharacters("Apparel");   
        // 写入catalog元素的结束标签   
        writer.writeEndElement();   
        // 写入catalogs元素的结束标签   
        writer.writeEndElement();   
        // 结束 XML 文档   
        writer.writeEndDocument();            
        writer.close();   
  
    }   
}   
  
test.xml:   
  
    
  
<?xml version="1.0" encoding="UTF-8"?>   
<catalogs>   
    <catalog id="001">Book</catalog>   
    <catalog id="002">Video</catalog>   
</catalogs>  
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

import javax.xml.namespace.QName;

import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;

public class StaxTest {

    public static void main( String[] arg ) throws XMLStreamException, FileNotFoundException {
        readXMLByStAX();
        writeXMLByStAX();
    }
    public static void readXMLByStAX() throws XMLStreamException, FileNotFoundException {
        XMLInputFactory factory = XMLInputFactory.newInstance();
        XMLEventReader  reader = factory.createXMLEventReader( StaxTest.class.getResourceAsStream( "test.xml" ) );
        XMLEvent event;
        StringBuffer  parsingResult = new StringBuffer();
        while( reader.hasNext() ) {
            event = reader.nextEvent();
            if( event.isStartElement() ) {
                StartElement se = event.asStartElement();
                parsingResult.append( "<" );
                parsingResult.append( se.getName() );
                if( se.getName().getLocalPart().equals( "catalog" ) ) {
                    parsingResult.append( "id="" );
                    parsingResult.append( se.getAttributeByName( new QName( "id" ) ).getValue());
                    parsingResult.append( """ ) ;
                }
                parsingResult.append( ">" );
            } else if( event.isCharacters() ) {
                parsingResult.append( event.asCharacters().getData() );
            } else if( event.isEndElement() ) {
                parsingResult.append( "</" );
                parsingResult.append( event.asEndElement().getName() );
                parsingResult.append( ">" );
            }
        }
        System.out.println( parsingResult );
    }
   
    public static void writeXMLByStAX() throws XMLStreamException, FileNotFoundException {
        XMLOutputFactory factory = XMLOutputFactory.newInstance();
        XMLStreamWriter writer = factory.createXMLStreamWriter( new FileOutputStream( "output.xml" ) );
        writer.writeStartDocument();
        writer.writeCharacters( " " );
        writer.writeComment( "testing comment" );
        writer.writeCharacters( " " );
        writer.writeStartElement( "catalogs" );
        writer.writeNamespace( "myNS", "" );
        writer.writeAttribute( "owner", "sina" );
        writer.writeCharacters( " " );
        writer.writeStartElement("", "catalog");
        writer.writeAttribute("id","007");
        writer.writeCharacters("Apparel");
        // 写入catalog元素的结束标签
        writer.writeEndElement();
        // 写入catalogs元素的结束标签
        writer.writeEndElement();
        // 结束 XML 文档
        writer.writeEndDocument();        
        writer.close();

    }

}

test.xml:

 

<?xml version="1.0" encoding="UTF-8"?>

<catalogs>
    <catalog id="001">Book</catalog>
    <catalog id="002">Video</catalog>
</catalogs>
8. Web Service. 由于Web服务日趋流行，利用Web服务的功能性的API特征正从最新的Java EE版本中向Java SE 6平台迁移。换言之，针对Web服务不需另外加入额外的工具，在Java EE和Java SE平台拥有相同的API。野马将大把不同的Web服务相关的API加到标准的工具柜中：以JSR 181针对Java 平台的Web服务元数据，通过JSR 224的基于XML 的Web服务Java API（JAX-WS）；针对Java的带有附件的SOAP API（SAAJ）作为JSR 67 。与三个Web服务API相关的包新增到Java SE 6.0里：JAX－WS API 放置到javax.xml.ws包； SAAJ类在javax.xml.soap 包； Web服务的元数据类放置在javax.jws包里。 下面是一个简单的例子，　下面的代码是要作为web service发布的类。
Java代码
package hello;   
import javax.jws.WebService;   
import javax.xml.ws.Endpoint;   
  
@WebService  
public class CircleFunctions {   
    public double getArea( int radius ) {   
        return Math.PI * radius * radius;   
    }   
    public double getCircumference( int radius ) {   
        return Math.PI * radius * 2;   
    }   
       
    public static void main( String[] args ) {   
        Endpoint.publish( "", new CircleFunctions());   
    }   
}  
package hello;
import javax.jws.WebService;
import javax.xml.ws.Endpoint;

@WebService

public class CircleFunctions {
    public double getArea( int radius ) {
        return Math.PI * radius * radius;
    }
    public double getCircumference( int radius ) {
        return Math.PI * radius * 2;
    }
   
    public static void main( String[] args ) {
        Endpoint.publish( "", new CircleFunctions());
    }
}
处理的方法如下：
javac -d ./ CircleFunctions.java
wsgen hello.CircleFunctions
java hello.CircleFunctions
然后在浏览器中输入如下url,你将得到一个xml页面：
http: //localhost:8888/WebServiceExample/circlefunctions?WSDL

参考网页：

1.Desktop和SystemTray.
2.Console.
3.Compiler API.
4.HttpServer API.
5. 对脚本语言的支持
6. 插入式注解处理API.
7.StAX.
8.Web Service.
9.JDK1.5的Annotation

 

本文来自CSDN博客，转载请标明出处：

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强烈建议你试试无所不能的CHAT-GPT，快点击我
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