Mybatis-Generator自动生成Dao、Model、Mapping…

2018-07-09 13:28:41来源：博客园阅读 ()

今天在学习mybatis生成相关的映射文件的时候，发现了往期的生成Dao、Model、Mapping等文章多数都是一样的，我也在学着重复造轮子，不过是懒人造的。本文旨在解决开发过程，简化配置文件的“手写”。

废话不多说，show me the code!

　　步骤一：新建普通maven工程,pom.xml文件配置如下：

 1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 2     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 3     <modelVersion>4.0.0</modelVersion>
 4     <groupId>com.generator</groupId>
 5     <artifactId>mybatis-gererator</artifactId>
 6     <version>0.0.1-SNAPSHOT</version>
 7 
 8     <properties>
 9         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
10     </properties>
11     <dependencies>
12         <!-- Mysql -->
13         <dependency>
14             <groupId>org.mybatis</groupId>
15             <artifactId>mybatis</artifactId>
16             <version>3.2.7</version>
17         </dependency>
18         <!-- Mysql 依赖 -->
19         <dependency>
20             <groupId>mysql</groupId>
21             <artifactId>mysql-connector-java</artifactId>
22             <version>5.1.6</version>
23         </dependency>
24         <!--生成代码插件 -->
25         <dependency>
26             <groupId>org.mybatis.generator</groupId>
27             <artifactId>mybatis-generator-core</artifactId>
28             <version>1.3.2</version>
29             <type>jar</type>
30         </dependency>
31     </dependencies>
32     <build>
33         <plugins>
34             <plugin>
35                 <artifactId>maven-war-plugin</artifactId>
36             </plugin>
37             <plugin>
38                 <artifactId>maven-compiler-plugin</artifactId>
39                 <configuration>
40                     <source>1.6</source>
41                     <target>1.6</target>
42                 </configuration>
43             </plugin>
44         </plugins>
45     </build>
46 </project>

　　步骤二：添加generatorConfig.xml（27行--31行可以不用急着写，请看步骤三）

 1 <?xml version="1.0" encoding="UTF-8" ?> 
 2 <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" 
 3 "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
 4 <generatorConfiguration>
 5  <context id="prod">
 6   <!-- RowBounds pagination -->
 7   <plugin type="org.mybatis.generator.plugins.RowBoundsPlugin" />
 8   <plugin type="org.mybatis.generator.plugins.CaseInsensitiveLikePlugin" />
 9   <plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
10 
11   <commentGenerator>
12    <property name="suppressDate" value="true" />
13    <property name="suppressAllComments" value="true" />
14   </commentGenerator>
15 
16   <!-- jdbc连接 -->
17   <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1:3306/shopping"
18    userId="root" password="1234" />
19 
20   <javaModelGenerator targetPackage="com.shopping.entity" targetProject="src/main/java">
21    <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
22    <property name="trimStrings" value="true" />
23   </javaModelGenerator>
24   <sqlMapGenerator targetPackage="mappers" targetProject="src/main/java" />
25   <javaClientGenerator targetPackage="com.shopping.mapper" targetProject="src/main/java" type="XMLMAPPER" />
26 
27   <table tableName="tb_address" domainObjectName="tbAddress"></table>
28   <table tableName="tb_areas" domainObjectName="tbAreas"></table>
29   <table tableName="tb_brand" domainObjectName="tbBrand"></table>
30   <table tableName="tb_cities" domainObjectName="tbCities"></table>
31   <table tableName="tb_user" domainObjectName="tbUser"></table>
32 
33  </context>
34 </generatorConfiguration>

　　步骤三：生成表的名字与别名的映射字符串

修改jdbc的相关配置参数，运行main方法，可以在控制台输出所有的表名与驼峰命名的表名映射关系xml对，然后从控制台中复制了贴回步骤二中的generatorConfig.xml，替换原有的27~31行。添加此步骤的目的在于表名过多的时候，优势就出来了。需要修改的地方也给大家标记出来了，怎么样，全程都在偷懒~

 1 package com.mybatis;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.ResultSet;
 6 import java.sql.SQLException;
 7 import java.sql.Statement;
 8 
 9 import org.mybatis.generator.api.ShellRunner;
10 
11 public class SqlMaperCreater {
12 
13     public static void main(String[] args) throws ClassNotFoundException, SQLException {
14 
15         // 生成表的名与别名对应xml
16         createTableMapping();
17 
18         //生成dao mapper entity对应文件
19         //args = new String[] { "-configfile", "src\\main\\resources\\gereratorConfig.xml", "-overwrite" };
20         //ShellRunner.main(args);
21     }
22 
23     public static void createTableMapping() throws ClassNotFoundException, SQLException {
24         String URL = "jdbc:mysql://127.0.0.1:3306/shopping?useUnicode=true&amp;characterEncoding=utf-8";
25         String USER = "root";
26         String PASSWORD = "1234";
27         // 1.加载驱动程序
28         Class.forName("com.mysql.jdbc.Driver");
29         // 2.获得数据库链接
30         Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
31         // 3.通过数据库的连接操作数据库，实现增删改查（使用Statement类）
32         Statement st = conn.createStatement();
33         ResultSet rs = st.executeQuery("select table_name from information_schema.tables where table_schema='shopping';");
34         // 4.处理数据库的返回结果(使用ResultSet类)
35         while (rs.next()) {
36             String tableName = rs.getString("table_name");
37             String xml = fotmatTableName2Xml(tableName);
38             System.out.println(xml);
39         }
40 
41         // 关闭资源
42         rs.close();
43         st.close();
44         conn.close();
45     }
46 
47     /**
48      * 格式化生成table名与别名的映射xml
49      * @param tableName
50      * @return
51      */
52     private static String fotmatTableName2Xml(String tableName) {
53         StringBuilder tableNamefmt = formatCamelName(tableName);
54         StringBuilder sb = new StringBuilder("<table tableName=\"");
55         sb.append(tableName).append("\" domainObjectName=\"").append(tableNamefmt).append("\"></table>");
56         return sb.toString();
57     }
58 
59     /**
60      * 将下划线大写方式命名的字符串转换为驼峰式。 例如：HELLO_WORLD->HelloWorld
61      * @param name 转换前的下划线大写方式命名的字符串
62      * @return 转换后的驼峰式命名的字符串StringBuilder
63      */
64     public static StringBuilder formatCamelName(String name) {
65 
66         StringBuilder result = new StringBuilder();
67         // 非法字符串过滤
68         if (name == null || name.isEmpty()) {
69             return result;
70         }
71 
72         // 不含下划线，仅将首字母小写
73         if (!name.contains("_")) {
74             return result.append(name.substring(0, 1).toLowerCase()).append(name.substring(1));
75         }
76 
77         // 用下划线将原始字符串分割
78         String camels[] = name.split("_");
79         for (String camel : camels) {
80             if (camel.isEmpty()) {
81                 continue;
82             }
83 
84             if (result.length() == 0) {
85                 result.append(camel.toLowerCase());
86                 continue;
87             }
88 
89             result.append(camel.substring(0, 1).toUpperCase());
90             result.append(camel.substring(1).toLowerCase());
91         }
92         return result;
93     }
94 
95 }