小傅哥 | 重学 Java 设计模式：实战中介者模式「按照Mybaits原理手写ORM框架，给JDBC方式操作数据库增加中介者场景」

.gitignore

@@ -25,3 +25,5 @@
 /itstack-demo-design-13-01/itstack-demo-design-13-01.iml
 /itstack-demo-design-13-02/itstack-demo-design-13-02.iml
 /itstack-demo-design-13-00/itstack-demo-design-13-00.iml
+/itstack-demo-design-16-02/itstack-demo-design-16-02.iml
+/itstack-demo-design-16-01/itstack-demo-design-16-01.iml

README.md

@@ -22,4 +22,5 @@
 
 - [`1. 重学 Java 设计模式：实战责任链模式「模拟618电商大促期间，项目上线流程多级负责人审批场景」`](https://bugstack.cn/itstack-demo-design/2020/06/18/%E9%87%8D%E5%AD%A6-Java-%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F-%E5%AE%9E%E6%88%98%E8%B4%A3%E4%BB%BB%E9%93%BE%E6%A8%A1%E5%BC%8F.html)
 - [`2. 重学 Java 设计模式：实战命令模式「模拟高档餐厅八大菜系，小二点单厨师烹饪场景」`](https://bugstack.cn/itstack-demo-design/2020/06/21/%E9%87%8D%E5%AD%A6-Java-%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F-%E5%AE%9E%E6%88%98%E5%91%BD%E4%BB%A4%E6%A8%A1%E5%BC%8F.html)
-- [`3. 重学 Java 设计模式：实战迭代器模式「模拟公司组织架构树结构关系，深度迭代遍历人员信息输出场景」`](https://bugstack.cn/itstack-demo-design/2020/06/23/%E9%87%8D%E5%AD%A6-Java-%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F-%E5%AE%9E%E6%88%98%E8%BF%AD%E4%BB%A3%E5%99%A8%E6%A8%A1%E5%BC%8F.html)
+- [`3. 重学 Java 设计模式：实战迭代器模式「模拟公司组织架构树结构关系，深度迭代遍历人员信息输出场景」`](https://bugstack.cn/itstack-demo-design/2020/06/23/%E9%87%8D%E5%AD%A6-Java-%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F-%E5%AE%9E%E6%88%98%E8%BF%AD%E4%BB%A3%E5%99%A8%E6%A8%A1%E5%BC%8F.html)
+- [`4. 重学 Java 设计模式：实战中介者模式「按照Mybaits原理手写ORM框架，给JDBC方式操作数据库增加中介者场景」`](https://bugstack.cn/itstack-demo-design/2020/06/27/%E9%87%8D%E5%AD%A6-Java-%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F-%E5%AE%9E%E6%88%98%E4%B8%AD%E4%BB%8B%E8%80%85%E6%A8%A1%E5%BC%8F.html)

itstack-demo-design-16-01/pom.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>itstack-demo-design</artifactId>
+        <groupId>org.itstack</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>itstack-demo-design-16-01</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>5.1.20</version>
+        </dependency>
+    </dependencies>
+</project>

itstack-demo-design-16-01/src/main/java/org/itstack/demo/design/JDBCUtil.java

@@ -0,0 +1,34 @@
+package org.itstack.demo.design;
+
+import com.alibaba.fastjson.JSON;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.Statement;
+
+public class JDBCUtil {
+
+    private static Logger logger = LoggerFactory.getLogger(JDBCUtil.class);
+
+    public static final String URL = "jdbc:mysql://172.25.64.119:3306/itstack_demo_ddd";
+    public static final String USER = "root";
+    public static final String PASSWORD = "JRTEST";
+
+    public static void main(String[] args) throws Exception {
+        //1.加载驱动程序
+        Class.forName("com.mysql.jdbc.Driver");
+        //2. 获得数据库连接
+        Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        //3.操作数据库，实现增删改查
+        Statement stmt = conn.createStatement();
+        ResultSet resultSet = stmt.executeQuery("SELECT id, name, age, createTime, updateTime FROM user");
+        //如果有数据，rs.next()返回true
+        while (resultSet.next()) {
+            logger.info("测试结果 姓名：{} 年龄：{}", resultSet.getString("name"),resultSet.getInt("age"));
+        }
+    }
+
+}

itstack-demo-design-16-02/itstack.sql

@@ -0,0 +1,10 @@
+DROP TABLE school;
+CREATE TABLE school ( id bigint NOT NULL AUTO_INCREMENT, name varchar(64), address varchar(256), createTime datetime, updateTime datetime, PRIMARY KEY (id) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+insert into school (id, name, address, createTime, updateTime) values (1, '北京大学', '北京市海淀区颐和园路5号', '2019-10-18 13:35:57', '2019-10-18 13:35:57');
+insert into school (id, name, address, createTime, updateTime) values (2, '南开大学', '中国天津市南开区卫津路94号', '2019-10-18 13:35:57', '2019-10-18 13:35:57');
+insert into school (id, name, address, createTime, updateTime) values (3, '同济大学', '上海市彰武路1号同济大厦A楼7楼7区', '2019-10-18 13:35:57', '2019-10-18 13:35:57');
+DROP TABLE user;
+CREATE TABLE user ( id bigint(11) NOT NULL AUTO_INCREMENT, name varchar(32), age int(4), address varchar(128), entryTime datetime, remark varchar(64), createTime datetime, updateTime datetime, status int(4) DEFAULT '0', dateTime varchar(64), PRIMARY KEY (id), INDEX idx_name (name) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+insert into user (id, name, age, address, entryTime, remark, createTime, updateTime, status, dateTime) values (1, '水水', 18, '吉林省榆树市黑林镇尹家村5组', '2019-12-22 00:00:00', '无', '2019-12-22 00:00:00', '2019-12-22 00:00:00', 0, '20200309');
+insert into user (id, name, age, address, entryTime, remark, createTime, updateTime, status, dateTime) values (2, '豆豆', 18, '辽宁省大连市清河湾司马道407路', '2019-12-22 00:00:00', '无', '2019-12-22 00:00:00', '2019-12-22 00:00:00', 1, null);
+insert into user (id, name, age, address, entryTime, remark, createTime, updateTime, status, dateTime) values (3, '花花', 19, '辽宁省大连市清河湾司马道407路', '2019-12-22 00:00:00', '无', '2019-12-22 00:00:00', '2019-12-22 00:00:00', 0, '20200310');

itstack-demo-design-16-02/pom.xml

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>itstack-demo-design</artifactId>
+        <groupId>org.itstack</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>itstack-demo-design-16-02</artifactId>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/dom4j/dom4j -->
+        <dependency>
+            <groupId>dom4j</groupId>
+            <artifactId>dom4j</artifactId>
+            <version>1.6.1</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/jaxen/jaxen -->
+        <dependency>
+            <groupId>jaxen</groupId>
+            <artifactId>jaxen</artifactId>
+            <version>1.1.6</version>
+        </dependency>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>5.1.20</version>
+        </dependency>
+        <dependency>
+            <groupId>org.mybatis</groupId>
+            <artifactId>mybatis</artifactId>
+            <version>3.4.6</version>
+        </dependency>
+    </dependencies>
+
+</project>

itstack-demo-design-16-02/src/main/java/org/itstack/demo/design/dao/ISchoolDao.java

@@ -0,0 +1,9 @@
+package org.itstack.demo.design.dao;
+
+import org.itstack.demo.design.po.School;
+
+public interface ISchoolDao {
+
+    School querySchoolInfoById(Long treeId);
+
+}

itstack-demo-design-16-02/src/main/java/org/itstack/demo/design/dao/IUserDao.java

@@ -0,0 +1,9 @@
+package org.itstack.demo.design.dao;
+
+import org.itstack.demo.design.po.User;
+
+public interface IUserDao {
+
+     User queryUserInfoById(Long id);
+
+}

itstack-demo-design-16-02/src/main/java/org/itstack/demo/design/mediator/Configuration.java

@@ -0,0 +1,30 @@
+package org.itstack.demo.design.mediator;
+
+import java.sql.Connection;
+import java.util.Map;
+
+
+/**
+ * 公众号 | bugstack虫洞栈
+ * 博 客 | https://bugstack.cn
+ * Create by 小傅哥 @2020
+ */
+public class Configuration {
+
+    protected Connection connection;
+    protected Map<String, String> dataSource;
+    protected Map<String, XNode> mapperElement;
+
+    public void setConnection(Connection connection) {
+        this.connection = connection;
+    }
+
+    public void setDataSource(Map<String, String> dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    public void setMapperElement(Map<String, XNode> mapperElement) {
+        this.mapperElement = mapperElement;
+    }
+
+}

itstack-demo-design-16-02/src/main/java/org/itstack/demo/design/mediator/DefaultSqlSession.java

@@ -0,0 +1,188 @@
+package org.itstack.demo.design.mediator;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.sql.*;
+import java.util.Date;
+import java.util.*;
+
+
+/**
+ * 公众号 | bugstack虫洞栈
+ * 博 客 | https://bugstack.cn
+ * Create by 小傅哥 @2020
+ */
+public class DefaultSqlSession implements SqlSession {
+
+    private Connection connection;
+    private Map<String, XNode> mapperElement;
+
+    public DefaultSqlSession(Connection connection, Map<String, XNode> mapperElement) {
+        this.connection = connection;
+        this.mapperElement = mapperElement;
+    }
+
+    @Override
+    public <T> T selectOne(String statement) {
+        try {
+            XNode xNode = mapperElement.get(statement);
+            PreparedStatement preparedStatement = connection.prepareStatement(xNode.getSql());
+            ResultSet resultSet = preparedStatement.executeQuery();
+            List<T> objects = resultSet2Obj(resultSet, Class.forName(xNode.getResultType()));
+            return objects.get(0);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    @Override
+    public <T> T selectOne(String statement, Object parameter) {
+        XNode xNode = mapperElement.get(statement);
+        Map<Integer, String> parameterMap = xNode.getParameter();
+        try {
+            PreparedStatement preparedStatement = connection.prepareStatement(xNode.getSql());
+            buildParameter(preparedStatement, parameter, parameterMap);
+            ResultSet resultSet = preparedStatement.executeQuery();
+            List<T> objects = resultSet2Obj(resultSet, Class.forName(xNode.getResultType()));
+            return objects.get(0);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    @Override
+    public <T> List<T> selectList(String statement) {
+        XNode xNode = mapperElement.get(statement);
+        try {
+            PreparedStatement preparedStatement = connection.prepareStatement(xNode.getSql());
+            ResultSet resultSet = preparedStatement.executeQuery();
+            return resultSet2Obj(resultSet, Class.forName(xNode.getResultType()));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    @Override
+    public <T> List<T> selectList(String statement, Object parameter) {
+        XNode xNode = mapperElement.get(statement);
+        Map<Integer, String> parameterMap = xNode.getParameter();
+        try {
+            PreparedStatement preparedStatement = connection.prepareStatement(xNode.getSql());
+            buildParameter(preparedStatement, parameter, parameterMap);
+            ResultSet resultSet = preparedStatement.executeQuery();
+            return resultSet2Obj(resultSet, Class.forName(xNode.getResultType()));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    private void buildParameter(PreparedStatement preparedStatement, Object parameter, Map<Integer, String> parameterMap) throws SQLException, IllegalAccessException {
+
+        int size = parameterMap.size();
+        // 单个参数
+        if (parameter instanceof Long) {
+            for (int i = 1; i <= size; i++) {
+                preparedStatement.setLong(i, Long.parseLong(parameter.toString()));
+            }
+            return;
+        }
+
+        if (parameter instanceof Integer) {
+            for (int i = 1; i <= size; i++) {
+                preparedStatement.setInt(i, Integer.parseInt(parameter.toString()));
+            }
+            return;
+        }
+
+        if (parameter instanceof String) {
+            for (int i = 1; i <= size; i++) {
+                preparedStatement.setString(i, parameter.toString());
+            }
+            return;
+        }
+
+        Map<String, Object> fieldMap = new HashMap<>();
+        // 对象参数
+        Field[] declaredFields = parameter.getClass().getDeclaredFields();
+        for (Field field : declaredFields) {
+            String name = field.getName();
+            field.setAccessible(true);
+            Object obj = field.get(parameter);
+            field.setAccessible(false);
+            fieldMap.put(name, obj);
+        }
+
+        for (int i = 1; i <= size; i++) {
+            String parameterDefine = parameterMap.get(i);
+            Object obj = fieldMap.get(parameterDefine);
+
+            if (obj instanceof Short) {
+                preparedStatement.setShort(i, Short.parseShort(obj.toString()));
+                continue;
+            }
+
+            if (obj instanceof Integer) {
+                preparedStatement.setInt(i, Integer.parseInt(obj.toString()));
+                continue;
+            }
+
+            if (obj instanceof Long) {
+                preparedStatement.setLong(i, Long.parseLong(obj.toString()));
+                continue;
+            }
+
+            if (obj instanceof String) {
+                preparedStatement.setString(i, obj.toString());
+                continue;
+            }
+
+            if (obj instanceof Date) {
+                preparedStatement.setDate(i, (java.sql.Date) obj);
+            }
+
+        }
+
+    }
+
+    private <T> List<T> resultSet2Obj(ResultSet resultSet, Class<?> clazz) {
+        List<T> list = new ArrayList<>();
+        try {
+            ResultSetMetaData metaData = resultSet.getMetaData();
+            int columnCount = metaData.getColumnCount();
+            // 每次遍历行值
+            while (resultSet.next()) {
+                T obj = (T) clazz.newInstance();
+                for (int i = 1; i <= columnCount; i++) {
+                    Object value = resultSet.getObject(i);
+                    String columnName = metaData.getColumnName(i);
+                    String setMethod = "set" + columnName.substring(0, 1).toUpperCase() + columnName.substring(1);
+                    Method method;
+                    if (value instanceof Timestamp) {
+                        method = clazz.getMethod(setMethod, Date.class);
+                    } else {
+                        method = clazz.getMethod(setMethod, value.getClass());
+                    }
+                    method.invoke(obj, value);
+                }
+                list.add(obj);
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return list;
+    }
+
+    @Override
+    public void close() {
+        if (null == connection) return;
+        try {
+            connection.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+}

itstack-demo-design-16-02/src/main/java/org/itstack/demo/design/mediator/DefaultSqlSessionFactory.java

@@ -0,0 +1,21 @@
+package org.itstack.demo.design.mediator;
+
+/**
+ * 公众号 | bugstack虫洞栈
+ * 博 客 | https://bugstack.cn
+ * Create by 小傅哥 @2020
+ */
+public class DefaultSqlSessionFactory implements SqlSessionFactory {
+
+    private final Configuration configuration;
+
+    public DefaultSqlSessionFactory(Configuration configuration) {
+        this.configuration = configuration;
+    }
+
+    @Override
+    public SqlSession openSession() {
+        return new DefaultSqlSession(configuration.connection, configuration.mapperElement);
+    }
+
+}