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设计模式

1、单例模式

 1 /**
 2  * 单例模式
 3  * @author feigu
 4  *
 5  */
 6 public class MonkeyKing {
 7     /**
 8      * 
 9      *懒汉式
10      */
11     private  static MonkeyKing instance;
12     public static Object lock=new Object();
13     //空参构造私有化
14     private MonkeyKing(){};
15     public static MonkeyKing getInstance(){
16         if(instance==null){
17             synchronized (lock) {
18                 if(instance==null){
19                     instance=new MonkeyKing();
20                 }
21                 return instance;
22             }
23         }
24         return instance;
25         
26     }
27 /**
28  * 饿韩式
29  */
30     private  static MonkeyKing instance=new MonkeyKing();
31     private MonkeyKing(){};
32     public static MonkeyKing getInstance(){
33         return instance;
34     }
35 }

2、Builder模式(链式编程)

 1 public class PhoneBuilder{
 2     public void test1(){
 3         Phone p=new Phone()
 4                 .setBrand("三星")
 5                 .setName("苹果")
 6                 .setPrice(899)
 7                 .setProductArea("江苏");
 8         System.out.println(p.getName());
 9         
10     }
11 }
12 
13  class Phone {
14     private String name;
15     private String brand;
16     private String productArea;
17     private float price;
18     public String getName() {
19         return name;
20     }
21     public Phone setName(String name) {//有返回值注意
22         this.name = name;
23         return this;
24     }
25     public String getBrand() {
26         return brand;
27     }
28     public Phone setBrand(String brand) {
29         this.brand = brand;
30         return this;
31     }
32     public String getProductArea() {
33         return productArea;
34     }
35     public Phone setProductArea(String productArea) {
36         this.productArea = productArea;
37         return this;
38     }
39     public float getPrice() {
40         return price;
41     }
42     public Phone setPrice(float price) {
43         this.price = price;
44         return this;
45     }
46     
47 }

3、适配器模式

 1 public class TestWindow {
 2     public static void main(String[] args) {
 3         Window w = new Window();
 4         w.setWindowListener(new WindowAdapter(){
 5             public void onMax() {
 6                 System.out.println("hello");
 7             }
 8         });
 9     }
10 }
11 
12 //预实现
13 class WindowAdapter implements WindowListener{
14     public void onMin() {
15     }
16 
17     public void onMax() {
18     }
19 
20     public void onClose() {
21     }
22 
23     public void onResize() {
24     }
25 }
26 
27 
28 
29 //接口
30 public interface WindowListener {
31     public void onMin();
32     public void onMax();
33     public void onClose();
34     public void onResize();
35 }
36 //窗口类
37 /**
38  * 窗口类 
39  */
40 public class Window {
41     
42     private int size;
43     private int location;
44 
45     public int getSize() {
46         return size;
47     }
48 
49     public void setSize(int size) {
50         this.size = size;
51     }
52 
53     public int getLocation() {
54         return location;
55     }
56 
57     public void setLocation(int location) {
58         this.location = location;
59     }
60     
61     public void setWindowListener(WindowListener l){
62         l.onMax();
63     }
64 }

4、工厂设计模式

 1 /**
 2  * 工厂设计模式
 3  */
 4 public class TestFactory {
 5     
 6     @Test
 7     public void test1(){
 8         TVSet tv = TVSetFactory.productTV();
 9         System.out.println(tv.getBrand());
10     }
11 }
12 
13 /**
14  * 工厂设计模式 
15  */
16 public class TVSetFactory {
17     
18     /**
19      * 静态工厂方法
20      */
21     public static TVSet productTV(){
22         TVSet tv = new TVSet();
23         tv.setBrand("三星");
24         tv.setName("xxx");
25         tv.setPrice(500.f);
26         return tv ;
27     }
28 }
29 
30 
31 /**
32  * TVSet
33  */
34 public class TVSet {
35     private String name;
36     private String brand;
37     private float price;
38 
39     public String getName() {
40         return name;
41     }
42 
43     public void setName(String name) {
44         this.name = name;
45     }
46 
47     public String getBrand() {
48         return brand;
49     }
50 
51     public void setBrand(String brand) {
52         this.brand = brand;
53     }
54 
55     public float getPrice() {
56         return price;
57     }
58 
59     public void setPrice(float price) {
60         this.price = price;
61     }
62 
63 }

5、装饰模式

 1 public class TestDecorate {
 2     
 3     @Test
 4     public void testFileWriter() throws Exception{
 5         //非缓冲区writer
 6         FileWriter fw = new FileWriter("d:/arch/a.txt");
 7         fw.write("hello");
 8         fw.close();
 9     }
10     
11     @Test
12     public void testBufferedWriter() throws Exception{
13         FileWriter fw = new FileWriter("d:/arch/a.txt");
14         //非缓冲区writer
15         BufferedWriter bw = new BufferedWriter(fw);
16         bw.write("hello");
17         //bw.flush();
18         bw.write("world");
19         //bw.flush();
20         
21         bw.close();
22         fw.close();
23     }
24 }

6、

//连接池
public ConnectionPool(String driver,String url,String user,String password){
        try {
            this.driver=driver;
            this.url=url;
            this.user=user;
            this.password=password;
            Class.forName(driver);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public void init() {
        // TODO Auto-generated method stub
        for(int i=0;i<Max;i++){
            try {
                //原生连接
                Connection conn = DriverManager.getConnection(url, user, password);
                connections.add(new WrappedConnection(conn, this));
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    //回收连接
    public synchronized void add(WrappedConnection c) {
        connections.add(c);
    }
    public synchronized Connection get() {
        if(connections.isEmpty()){
            return null;
        }
        return connections.remove(0);
    }

}
//连接池测试
public class TestConnectionPool {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        MyDataSource ds=new MyDataSource();
        try {
            Connection conn = ds.getConnection();
            PreparedStatement pst = conn.prepareStatement("insert into student values(7,‘lis‘,‘henan‘)");
            pst.executeUpdate();
            pst.close();
            conn = ds.getConnection();
             pst = conn.prepareStatement("insert into student values(8,‘lise‘,‘henan‘)");
            pst.executeUpdate();
            pst.close();
            conn = ds.getConnection();
             pst = conn.prepareStatement("insert into student values(9,‘lisr‘,‘henan‘)");
            pst.executeUpdate();
            pst.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

//池连接包装类
public class WrappedConnection extends ConnectionAdapter {
    private Connection rawConn;
    private ConnectionPool pool;
    
    public WrappedConnection(Connection rawConn, ConnectionPool pool) {
        super();
        this.rawConn = rawConn;
        this.pool = pool;
    }

    @Override
    public void commit() throws SQLException {
        rawConn.commit();
    }

    @Override
    public void rollback() throws SQLException {
        rawConn.rollback();
    }
//关闭连接
    @Override
    public void close() throws SQLException {
        pool.add(this);
        rawConn.close();
    }

    @Override
    public PreparedStatement prepareStatement(String sql) throws SQLException {
        return rawConn.prepareStatement(sql);
    }
}

//适配器
public class ConnectionAdapter implements Connection {
    
    @Override
    public <T> T unwrap(Class<T> iface) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
。。。。
}

//数据源
public class MyDataSource implements DataSource {
    private ConnectionPool pool;
     public MyDataSource() {
         String driver="com.mysql.jdbc.Driver";
         String url="jdbc:mysql://localhost:3306/big";
         String user="root";
         String password="root";
         pool=new ConnectionPool(driver,url,user,password);
         //初始化连接池
         pool.init();
    }
     @Override
     public Connection getConnection() throws SQLException {
         // TODO Auto-generated method stub
         return pool.get();
     }
    @Override
    public PrintWriter getLogWriter() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void setLogWriter(PrintWriter out) throws SQLException {
        // TODO Auto-generated method stub

    }

 

设计模式