添加代理和热部署

src/dynamic/DynamicProxyTest.java

+package dynamic;
+
+import java.io.ByteArrayOutputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+import sun.misc.ProxyGenerator;
+
+public class DynamicProxyTest {
+
+	static interface IHello{
+		
+		void sayHello();
+		
+	}
+	
+	static class Hello implements IHello{
+		
+		public void sayHello(){
+			System.out.println("hello world");
+		}
+	}
+	
+	static class DynamicProxy implements InvocationHandler{
+		
+		private Object orig;
+		
+		public DynamicProxy(Object orig){
+			this.orig=orig;
+			
+		}
+
+		//代理处理
+		@Override
+		public Object invoke(Object arg0, Method arg1, Object[] arg2)
+				throws Throwable {
+			System.out.println("hello proxy");
+			return arg1.invoke(orig, arg2);
+		}
+		
+	}
+	
+	
+	/**
+	 * @param args
+	 * @throws IOException 
+	 */
+	public static void main(String[] args) throws IOException {
+		
+		//ystem.getProperties().put("sun.misc.ProxyGenerator.saveGeneratedFiles", "true");
+		Class[] interfaces=new Class[]{
+				IHello.class
+		};
+		
+		Hello hello=new Hello();
+		
+		IHello proxy=(IHello)Proxy.newProxyInstance(DynamicProxy.class.getClassLoader(),interfaces, new DynamicProxy(hello));
+		
+		FileOutputStream os=new FileOutputStream("d:/$Proxy12.class"); 
+		byte[] file=ProxyGenerator.generateProxyClass("$Proxy12", new Class[]{IHello.class});
+		os.write(file);
+		os.flush();
+		os.close();
+		proxy.sayHello();
+	}
+
+}

src/hotswap/bytechange/ByteUtils.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+/**
+ * 关于字节码操作工具类
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class ByteUtils {
+
+    public static int bytes2Int(byte[] bytes,int start,int len){
+        int sum=0;
+        int end=start+len;
+        for(int i=start;i<end;i++){
+            int n=((int)bytes[i])&0xff;
+            n<<=(--len)*8;
+            sum+=n;
+        }
+        return sum;
+    }
+    
+    public static byte[] int2Bytes(int value,int len){
+        byte[] b=new byte[len];
+        for(int i=0; i< len ;i++){
+            b[len-i-1]=(byte)((value>>8*i)&0xff);
+            
+        }
+        return b;
+    }
+    
+    public static String bytes2String(byte[] bytes,int start, int len){
+        return new String(bytes,start,len);
+    }
+    
+    public static byte[] string2Bytes(String str){
+        
+        return str.getBytes();
+    }
+    
+    public static byte[] bytesReplace(byte[] originalBytes,int offset,int len,byte[] replaceBytes){
+        byte[] newBytes=new byte[originalBytes.length+(replaceBytes.length-len)];
+        System.arraycopy(originalBytes, 0, newBytes, 0, offset);
+        System.arraycopy(replaceBytes, 0, newBytes, offset, replaceBytes.length);
+        System.arraycopy(originalBytes, offset+len, newBytes, offset+replaceBytes.length, originalBytes.length-offset-len);
+        return newBytes;
+    }
+    
+}
+

src/hotswap/bytechange/ClassModifier.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+/**
+ * 类字节码修改类
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class ClassModifier {
+
+    /**Class文件 中常量池的起始偏移*/
+    private  static final int CONSTANT_POOL_COUNT_INDEX=8;
+    
+    /**CONSTANT_UTF8_INFO 常量的tag标志*/
+    private static final int CONSTANT_UTF8_INFO=1;
+    
+    /**常量池中11 种常量所占的长度，CONSTANTS_UTF8_INFO型常量除外，因为它不是定长的*/
+    private static final int[] CONSTANT_ITEM_LENGTH={-1,-1,-1,5,5,9,9,3,3,5,5,5,5};
+    
+    private static final int u1=1;
+    
+    private static final int u2=2;
+    
+    private byte[] classByte;
+    
+    public ClassModifier(byte[] classByte){
+        this.classByte=classByte;
+    }
+    
+    /**
+     * 
+     * 将class 常量池中特定字面量进行替换
+     *
+     * @param oldStr
+     * @param newStr
+     * @return      
+     * @since  Ver 3.0
+     */
+    public byte[] modifyUTF8Constant(String oldStr,String newStr){
+        
+        int constantsPoolSize=this.getConstantsPoolSize();
+        
+        int offset=CONSTANT_POOL_COUNT_INDEX+u2;
+        
+        for(int i=0;i<constantsPoolSize;i++){
+            int tag=ByteUtils.bytes2Int(classByte, offset, u1);
+            if(tag==CONSTANT_UTF8_INFO){
+                
+                int len=ByteUtils.bytes2Int(classByte, offset+u1, u2);
+                offset+=u1+u2;
+                String str=ByteUtils.bytes2String(classByte, offset, len);
+                if(str.equals(oldStr)){
+                    byte[] newStrBytes=ByteUtils.string2Bytes(newStr);
+                    byte[] newStrLen=ByteUtils.int2Bytes(newStr.length(),u2);
+                    classByte=ByteUtils.bytesReplace(classByte, offset-u2, u2, newStrLen);
+                    classByte=ByteUtils.bytesReplace(classByte, offset, len, newStrBytes);
+                    return classByte;
+                }else{
+                    offset+=len;
+                }
+                
+            }else{
+                offset+=CONSTANT_ITEM_LENGTH[tag];
+            }
+        }
+        return classByte;
+        
+    }
+    
+    /**
+     * 
+     * 返回常量池个数
+     *
+     * @return      
+     * @since  Ver 3.0
+     */
+    private int getConstantsPoolSize(){
+        return ByteUtils.bytes2Int(this.classByte, CONSTANT_POOL_COUNT_INDEX, u2);
+    }
+    
+}
+

src/hotswap/bytechange/Demo1Test.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+/**
+ * TODO
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class Demo1Test {
+
+    public void print() {
+        
+        System.out.println("demo1 print");
+        
+    }
+
+}
+

src/hotswap/bytechange/DemoExec.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+/**
+ * TODO
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class DemoExec {
+    
+    
+    public DemoExec(){
+        
+        Demo1Test test=new Demo1Test();
+        test.print();
+        
+    }
+    
+}
+

src/hotswap/bytechange/DemoTest.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+/**
+ * TODO
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class DemoTest {
+
+    public void print() {
+        
+        System.out.println("print demo");
+        
+    }
+    
+}
+

src/hotswap/bytechange/HotSwapClassLoader.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 热替换类加载器
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class HotSwapClassLoader extends ClassLoader {
+
+    public HotSwapClassLoader(){
+        super(HotSwapClassLoader.class.getClassLoader());
+    }
+    
+    public Class<?> loadClass(byte[] bytes){
+        
+        List<String> strList=new ArrayList<String>();
+        
+        List list=strList;
+        
+        list.add("ddff");
+        
+        
+        return defineClass(null, bytes, 0, bytes.length);
+        
+        
+        
+    }
+}
+

src/hotswap/bytechange/Main.java

+/**
+ * *********************** 版权声明 ***********************************
+ *
+ * 版权所有：wgz
+ * ©CopyRight wgz03310126 2014   
+ *  
+ * *******************************************************************
+*/
+
+package hotswap.bytechange;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * TODO
+ *
+ * @author    wgz
+ * @version   Ver 3.0
+ * @since     Ver 3.0
+ * @Date      2014-8-22
+ *
+ */
+public class Main {
+
+    /**
+     * TODO
+     *
+     * @param args      
+     * @throws IOException 
+     * @throws IllegalAccessException 
+     * @throws InstantiationException 
+     * @since  Ver 3.0
+     */
+
+    public static void main(String[] args) throws IOException, InstantiationException, IllegalAccessException {
+
+         execute();
+         System.gc();
+    }
+    
+    private static void execute() throws IOException, InstantiationException, IllegalAccessException{
+        DemoExec orgi=new DemoExec();
+        
+        HotSwapClassLoader loader=new HotSwapClassLoader();
+        
+        InputStream in=Main.class.getResourceAsStream("DemoExec.class");
+        
+        byte[] classByte=new byte[in.available()];
+        in.read(classByte);
+        ClassModifier modifier=new ClassModifier(classByte);
+        classByte=modifier.modifyUTF8Constant("hotswap/bytechange/Demo1Test", "hotswap/bytechange/DemoTest");
+        
+        loader.loadClass(classByte).newInstance();
+    }
+
+}
+