002-基本业务搭建【日志,工具类dbutils,dbcp等使用】

一、需求分析

1.1、概述

1、用户进入“客户管理”，通过列表方式查看用户；

2、客户名称，模糊查询用户列表

3、客户名称，可查看客户详细信息

4、新增、编辑、删除功能等

二、系统设计

　　需要对原始需求进行分析，找出Use Case（用例），然后设计表结构，画原型图，定义URL规范。

　　设计过程是由粗到细，由表及里。注意：设计阶段不涉及具体技术实现。

2.1、用例设计

　　查询用户、显示客户列表、显示客户基本信息、创建客户、编辑客户、删除客户

　　建议使用UML用例图展示，更加直观

2.2、数据库表设计

　　

 2.3、设计界面原型

　　可以使用Mockplus、axure 等工具设计界面原型。

2.4、设计URL

　　

注：还有其他设计过程，如数据模型，业务流程等。略。最终会形成一份设计文档。

三、代码开发

　　https://github.com/bjlhx15/smart-framework.git

知识点1 单元测试

引用包

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

　　在需要添加测试的类中使用快捷键：ctrl+alt+T即可

　　单元测试需要使用的配置，可在test下增加resources，并且右键→Mark Directory as/Resources Root。

　　需要注意main/java，main/resources，test/java，test/resources都是classpath的根目录，当运行单元测试的时候，遵循“就近原则”，即先从test/java，test/resources加载类或配置文件。

知识点2 日志使用

添加slf4j依赖，用于提供日志API，使用Log4j作为实现，POM配置

        <!--slf4j 日志 默认使用log4j-->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.7</version>
        </dependency>

在resource下增加log4j.properties文件

log4j.rootLogger=ERROR,console,file

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%m%n

log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File=${user.home}/logs/book.log
log4j.appender.file.DatePattern='_'yyyyMMdd
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{HH:mm:ss SSS} %p %c (%L) %m%n

log4j.logger.com.lhx=DEBUG

提供了两种方式的日志，包com.lhx下的日志级别是debug

知识点3 commons工具类的使用

       <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-collections4</artifactId>
            <version>4.1</version>
        </dependency>

知识点4 Dbutil应用以及threadlocal应用

        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <!--commons-dbutils -->
        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.6</version>
        </dependency>

DatabaseHelper代码

package com.lhx.chapter2.helper;

import com.lhx.chapter2.util.PropsUtil;
import com.sun.org.apache.regexp.internal.REUtil;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.collections4.MapUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 * db链接工具
 */
public class DatabaseHelper {
    private static final Logger log = LoggerFactory.getLogger(DatabaseHelper.class);

    private static final String DRIVER;
    private static final String URL;
    private static final String USERNAME;
    private static final String PASSWORD;

    private static final QueryRunner QUERY_RUNNER ;
    private static final ThreadLocal<Connection> CONNECTION_HOLDER ;

    static {
        QUERY_RUNNER = new QueryRunner();
        CONNECTION_HOLDER = new ThreadLocal<>();
        Properties conf = PropsUtil.loadProps("config.properties");
        DRIVER = conf.getProperty("jdbc.driver");
        URL = conf.getProperty("jdbc.url");
        USERNAME = conf.getProperty("jdbc.username");
        PASSWORD = conf.getProperty("jdbc.password");
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            log.error("类加载失败", e);
        }
    }

    public static Connection getConnection() {
        Connection conn = CONNECTION_HOLDER.get();
        if (conn == null) {
            try {
                conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
            } catch (SQLException e) {
                log.error("获取链接失败", e);
            } finally {
                CONNECTION_HOLDER.set(conn);
            }
        }
        return conn;
    }

    public static void closeConnection() {
        Connection conn = CONNECTION_HOLDER.get();
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                log.error("关闭链接失败", e);
            } finally {
                CONNECTION_HOLDER.remove();
            }
        }
    }

    public static <T> List<T> queryEntityList(Class<T> entityClass, String sql, Object... parmas) {
        List<T> entityList;
        try {
            entityList = QUERY_RUNNER.query(getConnection(), sql, new BeanListHandler<T>(entityClass), parmas);
        } catch (SQLException e) {
            log.error("查询实体失败", e);
            throw new RuntimeException(e);
        } finally {
            closeConnection();
        }
        return entityList;
    }

    public static <T> T queryEntity(Class<T> entityClass, String sql, Object... parmas) {
        T entity;
        try {
            entity = QUERY_RUNNER.query(getConnection(), sql, new BeanHandler<T>(entityClass), parmas);
        } catch (SQLException e) {
            log.error("查询实体失败", e);
            throw new RuntimeException(e);
        } finally {
            closeConnection();
        }
        return entity;
    }

    public static List<Map<String, Object>> excuteQuery(String sql, Object... parmas) {
        List<Map<String, Object>> result;
        try {
            result = QUERY_RUNNER.query(getConnection(), sql, new MapListHandler(), parmas);
        } catch (SQLException e) {
            log.error("查询失败", e);
            throw new RuntimeException(e);
        } finally {
            closeConnection();
        }
        return result;
    }

    public static int excuteUpdate(String sql, Object... parmas) {
        int rows = 0;
        try {
            rows = QUERY_RUNNER.update(getConnection(), sql, parmas);
        } catch (SQLException e) {
            log.error("更新失败", e);
            throw new RuntimeException(e);
        } finally {
            closeConnection();
        }
        return rows;
    }

    private static String getTableName(Class<?> entityClass) {
        return entityClass.getSimpleName();
    }

    public static <T> boolean insertEntity(Class<T> entityClass, Map<String, Object> filedMap) {
        if (MapUtils.isEmpty(filedMap)) {
            log.error("请求插入的map不能为空");
            return false;
        }

        String sql = "insert into " + getTableName(entityClass);
        StringBuilder columns = new StringBuilder("(");
        StringBuilder values = new StringBuilder("(");
        for (String filedName : filedMap.keySet()) {
            columns.append(filedName).append(", ");
            values.append("?, ");
        }
        columns.replace(columns.lastIndexOf(", "), columns.length(), ")");
        values.replace(values.lastIndexOf(", "), values.length(), ")");
        sql += columns + " values " + values;
        Object[] parmas = filedMap.values().toArray();
        return excuteUpdate(sql, parmas) == 1;
    }

    public static <T> boolean updateEntity(Class<T> entityClass, long id, Map<String, Object> filedMap) {
        if (MapUtils.isEmpty(filedMap)) {
            log.error("请求更新的map不能为空");
            return false;
        }

        String sql = "update " + getTableName(entityClass) + " set ";
        StringBuilder columns = new StringBuilder();
        for (String filedName : filedMap.keySet()) {
            columns.append(filedName).append("=?, ");
        }
        sql += columns.substring(0, columns.lastIndexOf(", ")) + "  where id=?";
        List<Object> paramsList = new ArrayList<>();
        paramsList.addAll(filedMap.values());
        paramsList.add(id);
        Object[] parmas = paramsList.toArray();
        return excuteUpdate(sql, parmas) == 1;
    }
    public static <T> boolean deleteEntity(Class<T> entityClass, long id) {
        String sql = "delete from  " + getTableName(entityClass) + " where id=? ";
        return excuteUpdate(sql, id) == 1;
    }
    public static void excuteSqlFile(String filePath) {
        String file = "sql/customer_init.sql";
        InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        String sql;
        try {
            while ((sql = reader.readLine()) != null) {
                excuteUpdate(sql);
            }
        } catch (IOException e) {
            log.error("文件读取异常", e);
            throw new RuntimeException(e);
        }
    }
}

知识点5 Dbutil、threadlocal、dbcp连接池应用 

        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <!--commons-dbutils -->
        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.6</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.1.1</version>
        </dependency>

DatabaseDbcpHelper代码

package com.lhx.chapter2.helper;

import com.lhx.chapter2.util.PropsUtil;
import org.apache.commons.collections4.MapUtils;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 *db链接工具
 */
public class DatabaseDbcpHelper {
    private static final Logger log = LoggerFactory.getLogger(DatabaseHelper.class);

    private static final QueryRunner QUERY_RUNNER;
    private static final ThreadLocal<Connection> CONNECTION_HOLDER;
    private static final BasicDataSource DATA_SOURCE;

    static {
        QUERY_RUNNER = new QueryRunner();
        CONNECTION_HOLDER = new ThreadLocal<>();
        DATA_SOURCE = new BasicDataSource();
        Properties conf = PropsUtil.loadProps("config.properties");
        String driver = conf.getProperty("jdbc.driver");
        String url = conf.getProperty("jdbc.url");
        String username = conf.getProperty("jdbc.username");
        String password = conf.getProperty("jdbc.password");
        DATA_SOURCE.setDriverClassName(driver);
        DATA_SOURCE.setUrl(url);
        DATA_SOURCE.setUsername(username);
        DATA_SOURCE.setPassword(password);
    }

    public static Connection getConnection() {
        Connection conn = CONNECTION_HOLDER.get();
        if (conn == null) {
            try {
                conn = DATA_SOURCE.getConnection();
            } catch (SQLException e) {
                log.error("获取链接失败", e);
            } finally {
                CONNECTION_HOLDER.set(conn);
            }
        }
        return conn;
    }

    public static <T> List<T> queryEntityList(Class<T> entityClass, String sql, Object... parmas) {
        List<T> entityList;
        try {
            entityList = QUERY_RUNNER.query(getConnection(), sql, new BeanListHandler<T>(entityClass), parmas);
        } catch (SQLException e) {
            log.error("查询实体失败", e);
            throw new RuntimeException(e);
        }
        return entityList;
    }

    public static <T> T queryEntity(Class<T> entityClass, String sql, Object... parmas) {
        T entity;
        try {
            entity = QUERY_RUNNER.query(getConnection(), sql, new BeanHandler<T>(entityClass), parmas);
        } catch (SQLException e) {
            log.error("查询实体失败", e);
            throw new RuntimeException(e);
        }
        return entity;
    }

    public static List<Map<String, Object>> excuteQuery(String sql, Object... parmas) {
        List<Map<String, Object>> result;
        try {
            result = QUERY_RUNNER.query(getConnection(), sql, new MapListHandler(), parmas);
        } catch (SQLException e) {
            log.error("查询失败", e);
            throw new RuntimeException(e);
        }
        return result;
    }

    public static int excuteUpdate(String sql, Object... parmas) {
        int rows = 0;
        try {
            rows = QUERY_RUNNER.update(getConnection(), sql, parmas);
        } catch (SQLException e) {
            log.error("更新失败", e);
            throw new RuntimeException(e);
        }
        return rows;
    }

    private static String getTableName(Class<?> entityClass) {
        return entityClass.getSimpleName();
    }

    public static <T> boolean insertEntity(Class<T> entityClass, Map<String, Object> filedMap) {
        if (MapUtils.isEmpty(filedMap)) {
            log.error("请求插入的map不能为空");
            return false;
        }

        String sql = "insert into " + getTableName(entityClass);
        StringBuilder columns = new StringBuilder("(");
        StringBuilder values = new StringBuilder("(");
        for (String filedName : filedMap.keySet()) {
            columns.append(filedName).append(", ");
            values.append("?, ");
        }
        columns.replace(columns.lastIndexOf(", "), columns.length(), ")");
        values.replace(values.lastIndexOf(", "), values.length(), ")");
        sql += columns + " values " + values;
        Object[] parmas = filedMap.values().toArray();
        return excuteUpdate(sql, parmas) == 1;
    }

    public static <T> boolean updateEntity(Class<T> entityClass, long id, Map<String, Object> filedMap) {
        if (MapUtils.isEmpty(filedMap)) {
            log.error("请求更新的map不能为空");
            return false;
        }

        String sql = "update " + getTableName(entityClass) + " set ";
        StringBuilder columns = new StringBuilder();
        for (String filedName : filedMap.keySet()) {
            columns.append(filedName).append("=?, ");
        }
        sql += columns.substring(0, columns.lastIndexOf(", ")) + "  where id=?";
        List<Object> paramsList = new ArrayList<>();
        paramsList.addAll(filedMap.values());
        paramsList.add(id);
        Object[] parmas = paramsList.toArray();
        return excuteUpdate(sql, parmas) == 1;
    }

    public static <T> boolean deleteEntity(Class<T> entityClass, long id) {
        String sql = "delete from  " + getTableName(entityClass) + " where id=? ";
        return excuteUpdate(sql, id) == 1;
    }

    public static void excuteSqlFile(String filePath) {
        String file = "sql/customer_init.sql";
        InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        String sql;
        try {
            while ((sql = reader.readLine()) != null) {
                if (StringUtils.isNotEmpty(sql)) {
                    excuteUpdate(sql);
                }
            }
        } catch (IOException e) {
            log.error("文件读取异常", e);
            throw new RuntimeException(e);
        }
    }
}

知识点6 Dbutils简述

DbUtils给我们提供了10个ResultSetHandler实现类，如下：

①ArrayHandler： 将查询结果的第一行数据，保存到Object数组中
②ArrayListHandler 将查询的结果，每一行先封装到Object数组中，然后将数据存入List集合
③BeanHandler 将查询结果的第一行数据，封装到user对象
④BeanListHandler 将查询结果的每一行封装到user对象，然后再存入List集合
⑤ColumnListHandler 将查询结果的指定列的数据封装到List集合中
⑥MapHandler 将查询结果的第一行数据封装到map结合（key==列名，value==列值）
⑦MapListHandler 将查询结果的每一行封装到map集合（key==列名，value==列值），再将map集合存入List集合
⑧BeanMapHandler 将查询结果的每一行数据，封装到User对象，再存入mao集合中（key==列名，value==列值）
⑨KeyedHandler 将查询的结果的每一行数据，封装到map1（key==列名，value==列值 ），然后将map1集合（有多个）存入map2集合（只有一个）
⑩ScalarHandler 封装类似count、avg、max、min、sum......函数的执行结果