3一、最简单的mvc框架tiny，增长Ioc，jdbc工具类（1个类），链接池（1个类）

时间  2019-11-10
标签 最简单 mvc 框架 tiny 增长 ioc jdbc 工具 链接 栏目 Java 繁體版
原文   原文链接

Ioc html

按照mvc，咱们须要把tiny分红3层，其中视图（Renderer抽象类）和Action咱们已经在前面实现了，此次咱们用最少的代码实现Model。 java

    model沿用Action的想法，用户自定义类，类名必须以Model结尾，同Action同样在初始化时放入Container容器内。model就是数据模型，咱们这里充血模型，model的类名默认是同数据库的表名作关联的，即类名去掉Model后（转为小写）为代表，这样一对一映射，有时会简单不少，如保存和查询单个表时，固然了你能够传入复杂sql，返回的结果有基本类型、map、list等。 c++

    model里须要访问数据库时，咱们设计了DbUtil工具类，建议在model里使用，固然了这个仍是看你，DbUtil自己没有限制。model是经过ioc注入进来的，在你访问这个action前。下面代码中的Container.inject(o);为容器向action中注入model实例。 git

Map<String,String> args = this.converter(req.getParameterMap());
            
            String key = UUID.randomUUID().toString();
            
            Container.inject(o);
            
            this.before(routes,args,key);
            
			Object result = o.getClass().getMethod(routes[1],Map.class).invoke(o,args);
			
			this.after(args,key);
			
			Container.clearReqAops(key);



Container.inject代码以下： 
public static void inject(Object o) throws IllegalArgumentException, IllegalAccessException, InstantiationException{
		Field filedArr[] = o.getClass().getDeclaredFields();
		for (Field field:filedArr) {
			String ftn = field.getType().getSimpleName();
			 if (ftn.endsWith("Model")) {
				 Object m = Container.getCls(ftn);
				 if(m != null){
					 field.set(o,((Class)m).newInstance());
				 }
			 }
		}
	}



咱们从容器中取出这个model类，而后实例化，注入到这个action的属性。

model的初始化，代码以下： web

if (className.endsWith("Action.class")) {
					packPath=packPath.replace(".class.", "");
					Object o = Class.forName(packPath).newInstance();
					String clsName = o.getClass().getSimpleName().substring(0,o.getClass().getSimpleName().lastIndexOf("Action"));
					if(clsMap.get(clsName) != null){
						new IllegalAccessException(clsName+" class 重复");
					}else{
						clsMap.put(clsName, o);
					}
				}else if (className.endsWith("Model.class")) {
					className=className.replace(".class", "");
					packPath=packPath.replace(".class.", "");
					Class o = Class.forName(packPath);
					if(clsMap.get(className) != null){
						new IllegalAccessException(className+" class 重复");
					}else{
						clsMap.put(className, o);
					}
				}



同action几乎同样，这里不细说。咱们看到增长model模型，咱们没有增长一个类，只是增长1个方法，和10几行代码。

模型的使用（数据库链接池还未测试） sql

testAction 数据库

package web;

import java.util.Map;

import tiny.ContextUtil;
import tiny.JspRenderer;
import tiny.Renderer;

public class TinyTestAction {
	public UserModel user;
	public void hello(Map<String,String> args){
		
		System.out.println("aa："+args.get("aa"));
		System.out.println("访问时间1："+System.currentTimeMillis());
		//ContextUtil.getContext().getXXX;
	}
	
	public String hello2(Map<String,String> args){
		return "/index.jsp";
	}
	
	public Renderer hello3(Map<String,String> args){
		//数据库
		Map<String,Object> data = user.outStr(args);
		return new JspRenderer("/index.jsp",data);
	}
}



model类 
package web;

import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

import tiny.DbUtil;

public class UserModel {
	public Map<String,Object> outStr(Map<String,String> params){
		try {
			//验证，参数转换
			Map<String,Object> args = new HashMap();
			
			//访问数据库
			Map<String,Object> data = DbUtil.dao.load(this, args);
			
			//业务逻辑处理
			return data;
		} catch (SQLException e) {
			e.printStackTrace();
			return null;
		}
	}
}



jdbc工具类 mvc

这个尚未开发全，model和表的自动映射只作了一个查询。（之后补上），其余的都已经实现。代码以下： oracle

package tiny;

import java.sql.Connection;
import java.sql.ParameterMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DbUtil {
	DataBase instance;
	//SqlLoader loader;
	public static final DbUtil dao = new DbUtil();
	public DbUtil(){
		instance = DataBase.instance();
		//loader = SqlLoader.instance();
	}
	
	public Map<String, Object> load(Object o, Map<String, Object> params)
			throws SQLException {
		Connection conn = instance.getConnection();
		PreparedStatement stmt = null;
		ResultSet rs = null;
		Map<String, Object> result = null;

		try {
			stmt = this.prepareStatement(conn, dao.modelConverterSql(o, params));
			rs = stmt.executeQuery();
			result = this.mapConverter(rs);
		} finally {
			try {
				close(rs);
			} finally {
				close(stmt);
			}
			instance.release(conn);
		}
		return result;
	}
	
	public Map<String, Object> load(String sql, Object[] params)
			throws SQLException {
		Connection conn = instance.getConnection();
		PreparedStatement stmt = null;
		ResultSet rs = null;
		Map<String, Object> result = null;

		try {
			stmt = this.prepareStatement(conn, sql);
			if (params != null) {
				this.setParams(stmt, params);
			}
			rs = stmt.executeQuery();
			result = this.mapConverter(rs);
		} finally {
			try {
				close(rs);
			} finally {
				close(stmt);
			}
			instance.release(conn);
		}
		return result;
	}

	public List<Map<String, Object>> query(String sql, Object[] params)
			throws SQLException {
		Connection conn = instance.getConnection();
		PreparedStatement stmt = null;
		ResultSet rs = null;
		List<Map<String, Object>> result = null;

		try {
			stmt = this.prepareStatement(conn, sql);
			if (params != null) {
				this.setParams(stmt, params);
			}
			rs = stmt.executeQuery();
			result = this.listConverter(rs);
		} finally {
			try {
				close(rs);
			} finally {
				close(stmt);
			}
			instance.release(conn);
		}
		return result;
	}

	public int update(String sql, Object[] params) throws SQLException {
		Connection conn = instance.getConnection();
		PreparedStatement stmt = null;
		int rows = 0;
		try {
			stmt = this.prepareStatement(conn, sql);
			this.setParams(stmt, params);
			rows = stmt.executeUpdate();
		} finally {
			close(stmt);
			instance.release(conn);
		}

		return rows;
	}
	public void setParams(PreparedStatement stmt, Object... params)
			throws SQLException {
		if (params == null) {
			return;
		}

		ParameterMetaData pmd = null;
		pmd = stmt.getParameterMetaData();
		if (pmd.getParameterCount() < params.length) {
			throw new SQLException("Too many parameters: expected "
					+ pmd.getParameterCount() + ", was given " + params.length);
		}
		for (int i = 0; i < params.length; i++) {
			if (params[i] != null) {
				stmt.setObject(i + 1, params[i]);
			} else {
				int sqlType = Types.VARCHAR;
				try {
					sqlType = pmd.getParameterType(i + 1);
				} catch (SQLException e) {
				}
				stmt.setNull(i + 1, sqlType);
			}
		}
	}

	private Map<String, Object> mapConverter(ResultSet rs) throws SQLException {
		Map<String, Object> result = null;
		if (rs.next()) {
			result = new HashMap<String, Object>();
			ResultSetMetaData metaData = rs.getMetaData();
			for (int i = 1; i <= metaData.getColumnCount(); i++) {
				String filed = metaData.getColumnName(i);
				result.put(filed, rs.getObject(filed));
			}
		}
		return result;
	}

	private List<Map<String, Object>> listConverter(ResultSet rs)
			throws SQLException {
		List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
		while (rs.next()) {
			ResultSetMetaData metaData = rs.getMetaData();
			Map<String, Object> rowData = null;
			for (int i = 1; i <= metaData.getColumnCount(); i++) {
				rowData = new HashMap<String, Object>();
				String filed = metaData.getColumnName(i);
				rowData.put(filed, rs.getObject(filed));
				result.add(rowData);
			}
		}
		if (result.size() > 0) {
			return result;
		} else {
			return null;
		}

	}

	private PreparedStatement prepareStatement(Connection conn, String sql)
			throws SQLException {
		return conn.prepareStatement(sql);
	}

	protected void close(Statement stmt) throws SQLException {
		if (stmt != null) {
			stmt.close();
		}
	}

	protected void close(ResultSet rs) throws SQLException {
		if (rs != null) {
			rs.close();
		}
	}
	

	private String modelConverterSql(Object o,Map<String, Object> params){
		String table = o.getClass().getSimpleName().replace("Model.", "").toLowerCase();
		StringBuffer sql = new StringBuffer();
		sql.append("select * from "+table+" where 1=1 ");
		if(params != null){
			for(String key : params.keySet()){
				Object v = params.get(key);
				if(v instanceof Integer){
					sql.append(" and " + key +"="+ v);
				}else if(v instanceof String){
					sql.append(" and " + key +"='"+v+"'");
				}else if(v instanceof String){
					//其余未实现
				}
			}
		}
		return sql.toString();
	}
}



我把查询的结果自动转化为map或list<map>,其中modelConverterSql为“ model和表的自动映射只作了一个查询”，很简单的，其余的增删改查我会补上。其中注释掉的“SqlLoader”，想把sql保存到文件里，而后用这个来读取。最下面有这个类的代码，也没有开发完就是思路雏形。（这个我不想在完善了，原本tiny就像想简单，感受分开sql了，反而会和tiny不协调，再说吧）。

链接池 app

我写了简单的链接池，能够默认初始化链接、不够是自增等，还未测试。（等测试后，咱们把代码放到oschina的git上）

这个等我完善后，在细说下。 

package tiny; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.Properties; import java.util.Vector; public class DataBase { private Vector<Connection> pool; private static int init_active = 10; private static int curr_active = 10; private static int max_active = 50; private static DataBase instance = null; private DataBase(){ pool = new Vector<Connection>(); InputStream propStream = DataBase.class.getResourceAsStream("/database.properties"); Properties props = new Properties(); if (propStream != null) { try { props.load(propStream); init_active = Integer.parseInt(props.getProperty("initial.active")); max_active = Integer.parseInt(props.getProperty("max.active")); //for(int c=0;c<init_active;c++){ for(int c=0;c<max_active;c++){ Class.forName(props.getProperty("jdbc.driver")); Connection conn = DriverManager.getConnection(props.getProperty("jdbc.url"),props.getProperty("jdbc.username"),props.getProperty("jdbc.password")); pool.add(conn); } } catch (Exception e) { e.printStackTrace(); } finally { try { propStream.close(); } catch (IOException e) { e.printStackTrace(); } } } } public synchronized void release(Connection conn){ pool.add(conn); } public synchronized void closePool(){ for(int c=0;c<pool.size();c++){ try { pool.get(c).close(); } catch (SQLException e) { e.printStackTrace(); } pool.remove(c); } } public static DataBase instance(){ if(instance == null){ instance = new DataBase(); } return instance; } public synchronized Connection getConnection(){ if(pool.size()>0){ Connection conn = pool.get(0); pool.remove(conn); return conn; }else{ return null; } } }



链接池访问的属性文件配置 

#jdbc.driver=oracle.jdbc.driver.OracleDriver #jdbc.url=jdbc:oracle:thin:@(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))(LOAD_BALANCE = yes)(CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = xe))) #jdbc.username=oneteam #jdbc.password=1q2w3e jdbc.driver=org.h2.Driver jdbc.url=jdbc:h2:./h2db/eternal jdbc.username=oneteam jdbc.password=1q2w3e initial.active=10 max.active=50



测试action 的index.jsp 

<%@ page language="java" pageEncoding="UTF-8" contentType="text/html;charset=UTF-8"%> <!DOCTYPE html> <html> <head> <base href="<%=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+request.getContextPath()+"/"%>"> <title>tiny-瘦成一道隐形闪电</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <p align="center"> tiny-瘦成一道隐形的闪电 </p> <p align="center"> <%     String dd = (String)request.getAttribute("name"); if(dd != null){ out.print(dd); } %> </p> </body> </html>


SqlLoader类 

package tiny;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
public class SqlLoader {
    private static SqlLoader instance = null;
    private Map<String,String> sqls = null;
    public static SqlLoader instance() {
    	if(instance == null){
    		instance = new SqlLoader();
    	}
        return instance;
    }

    private SqlLoader() {
		InputStream propStream = SqlLoader.class.getResourceAsStream("/sqls.properties");
		Properties props = new Properties();
		if (propStream != null) {
			try {
				props.load(propStream);
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					propStream.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			sqls = (HashMap<String,String>)(new HashMap(props));
		}
    }

    @SuppressWarnings("unchecked")
    protected String get(String key) throws IOException {
    	if(sqls == null){
    		return null;
    	}
        return sqls.get(key);
    }
    public synchronized void unload(){
        this.sqls = null;
    }

}



总结

    tiny的开发就是忽然的想法，虽然前先后后加一块儿开发的时间也就1天，可是咱们仍是开发出了不少东西的，实际使用时问题确定是有的，tiny的开发主要想实现我当时的想法“瘦成一道隐形的闪电”，就是代码少的不能在少了，完全0配置，不说你都不知道有action、model啥的（娱乐因素比较多，呵呵），最后的闪电就是tiny虽小，可是功能仍是不少的action、多视图支持、aop、ioc、model充血模型、链接池、jdbc的dao封装等，也算一道小闪电。呵呵。

    tiny还有一个就是一直吵吵要增长的java调用前台js的，这个一直没实现，这个在酝酿，不过第一次写时就预留了，看西面代码： 

//@WebFilter(urlPatterns = { "/demoAsyncLink" }, asyncSupported = true)
@WebFilter(urlPatterns = { "/ty/*" })
public class FrontControl implements Filter{
上面注释掉的注解，就是用来实现这个的。
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