最近一直都在學(xué)習(xí)java，發(fā)現(xiàn)目前java招聘中，mybatis出現(xiàn)的頻率挺高的，可能是目前java開發(fā)中使用比較多的數(shù)據(jù)庫orm框架。于是我準(zhǔn)備研究下spring boot和mybatis的整合。
1.在pom.xml文件中添加下面的配置
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
<dependencies> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-web</artifactid> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-test</artifactid> <scope>test</scope> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-jdbc</artifactid> </dependency> <dependency> <groupid>mysql</groupid> <artifactid>mysql-connector-java</artifactid> <scope>runtime</scope> </dependency> <dependency> <groupid>com.alibaba</groupid> <artifactid>druid</artifactid> <version>1.0.29</version> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-data-jpa</artifactid> </dependency> <!-- 這個(gè)是官方的mybatis依賴，這個(gè)你不加沒法用噻 --> <dependency> <groupid>org.mybatis.spring.boot</groupid> <artifactid>mybatis-spring-boot-starter</artifactid> <version>1.3.2</version> </dependency> <!-- 這個(gè)是自動(dòng)生成mapper等的依賴，必須得加--> <dependency> <groupid>org.mybatis.generator</groupid> <artifactid>mybatis-generator</artifactid> <version>1.3.5</version> <type>pom</type> </dependency> <!--這個(gè)是自動(dòng)生成mapper等的依賴，必須得加 https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core --> <dependency> <groupid>org.mybatis.generator</groupid> <artifactid>mybatis-generator-core</artifactid> <version>1.3.5</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> <plugin> <groupid>org.mybatis.generator</groupid> <artifactid>mybatis-generator-maven-plugin</artifactid> <version>1.3.2</version> <configuration> <!--配置文件存放的地址--> <!--<configurationfile>src/main/resources/mybatis-generator/generatorconfig.xml</configurationfile>--> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> </plugin> </plugins> </build> |
2.在application.properties配置文件中進(jìn)行數(shù)據(jù)庫和mybatis掃描的配置
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
spring.datasource.driver-class-name=com.mysql.jdbc.driverspring.datasource.url=jdbc:mysql://localhost:3306/yddy?useunicode=true&characterencoding=utf-8&servertimezone=utcspring.datasource.username=rootspring.datasource.password=123456mybatis.config-locations=classpath:mybatis-config.xml# mapper文件mybatis.mapper-locations=classpath:mapper/*.xml #這里直接寫*，對后面自定義sql，編寫xxxext.xml有好處，自動(dòng)掃描到這些文件，不用再改配置了mybatis.type-aliases-package=com.dameiweb.learn.modellogging.level.com.dameiweb.learn.dao=debug#mybatis.config = mybatis 配置文件名稱#mybatis.mapperlocations = mapper xml 文件地址#mybatis.typealiasespackage = 實(shí)體類包路徑#mybatis.typehandlerspackage = type handlers 處理器包路徑#mybatis.check-config-location = 檢查 mybatis 配置是否存在，一般命名為 mybatis-config.xml#mybatis.executortype = 執(zhí)行模式。默認(rèn)是 simple |
3.mybatis的配置和自動(dòng)生成mapper的配置
在resource目錄下新建一個(gè)generatorconfig.xml和mybatis-config.xml。內(nèi)容如下：
generatorconfig.xml內(nèi)容
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
<?xml version="1.0" encoding="utf-8"?><!doctype generatorconfiguration public "-//mybatis.org//dtd mybatis generator configuration 1.0//en" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"><generatorconfiguration> <classpathentry location="c:\users\nick\.m2\repository/mysql/mysql-connector-java/5.1.46/mysql-connector-java-5.1.46.jar"/> <context id="db2tables" targetruntime="mybatis3"> <commentgenerator> <property name="suppressdate" value="true"/> <property name="suppressallcomments" value="true"/> </commentgenerator> <!--數(shù)據(jù)庫鏈接地址賬號密碼--> <jdbcconnection driverclass="com.mysql.jdbc.driver" connectionurl="jdbc:mysql://localhost:3306/yddy?useunicode=true&characterencoding=utf-8&servertimezone=utc" userid="root" password="123456"> </jdbcconnection> <javatyperesolver> <property name="forcebigdecimals" value="false"/> </javatyperesolver> <!--生成model類存放位置--> <javamodelgenerator targetpackage="com.dameiweb.learn.model" targetproject="src/main/java"> <property name="enablesubpackages" value="true"/> <!-- 從數(shù)據(jù)庫返回的值被清理前后的空格 --> <property name="trimstrings" value="false"/> </javamodelgenerator> <!--生成映射文件存放位置--> <sqlmapgenerator targetpackage="mapper" targetproject="src/main/resources"> <property name="enablesubpackages" value="true"/> </sqlmapgenerator> <!--生成dao類存放位置--> <!-- 客戶端代碼，生成易于使用的針對model對象和xml配置文件 的代碼 type="annotatedmapper",生成java model 和基于注解的mapper對象 type="mixedmapper",生成基于注解的java model 和相應(yīng)的mapper對象 type="xmlmapper",生成sqlmap xml文件和獨(dú)立的mapper接口 --> <javaclientgenerator type="xmlmapper" targetpackage="com.dameiweb.learn.dao" targetproject="src/main/java"> <property name="enablesubpackages" value="true"/> </javaclientgenerator> </context></generatorconfiguration> |
mybatis-config.xml的內(nèi)容：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
<?xml version="1.0" encoding="utf-8" ?><!doctype configuration public "-//mybatis.org//dtd config 3.0//en" "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration> <settings> <setting name="callsettersonnulls" value="true"/> <setting name="cacheenabled" value="true"/> <setting name="lazyloadingenabled" value="true"/> <setting name="aggressivelazyloading" value="true"/> <setting name="multipleresultsetsenabled" value="true"/> <setting name="usecolumnlabel" value="true"/> <setting name="usegeneratedkeys" value="false"/> <setting name="automappingbehavior" value="partial"/> <setting name="defaultexecutortype" value="simple"/> <setting name="mapunderscoretocamelcase" value="true"/> <setting name="localcachescope" value="session"/> <setting name="jdbctypefornull" value="null"/> </settings> <typealiases> <typealias alias="integer" type="java.lang.integer" /> <typealias alias="long" type="java.lang.long" /> <typealias alias="hashmap" type="java.util.hashmap" /> <typealias alias="linkedhashmap" type="java.util.linkedhashmap" /> <typealias alias="arraylist" type="java.util.arraylist" /> <typealias alias="linkedlist" type="java.util.linkedlist" /> </typealiases></configuration> |
這樣我們就配置好了spring boot和mybatis與mybatis自動(dòng)生成mapper和實(shí)體的功能。這樣我們要生成某個(gè)表的實(shí)體和mapper的時(shí)候，只需要在generatorconfig.xml中javaclientgenerator標(biāo)簽之后添加下面的內(nèi)容即可。
此處我們已yd_movies表為例(主要數(shù)據(jù)庫表名字不要用復(fù)數(shù)，這個(gè)表名肯定是我之前腦子抽了，搞個(gè)復(fù)數(shù)的名字)
|
1
2
3
4
5
6
7
8
9
10
11
12
13
|
<!--生成對應(yīng)表及類名--> <table tablename="yd_movies" domainobjectname="movie" enablecountbyexample="false" enableupdatebyexample="false" enabledeletebyexample="false" enableselectbyexample="false" selectbyexamplequeryid="false"> <columnoverride column="cover_photos" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="cover_photos_loc" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="pubdates" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="photographs_origin" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="photographs_origin_loc" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="languages" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="awards" javatype="java.lang.string" jdbctype="varchar" /> <columnoverride column="summary" javatype="java.lang.string" jdbctype="varchar" /> </table><!--columnoverride使用這個(gè)標(biāo)簽是為了防止數(shù)據(jù)庫字段類型為text時(shí)候，mybatis會生成xxxxwithblobs文件。--> |
然后點(diǎn)擊idea右側(cè)maven projects，就可以看到mybatis-generate下的mybatis-generate：generate，雙擊mybatis-generate：generate即可。
**generator 注意點(diǎn)，也可以說是bug
就是在生成的時(shí)候，在第二次生成的時(shí)候，dao 和entity 都會直接覆蓋，而mapper.xml 會直接追加，導(dǎo)致運(yùn)行報(bào)錯(cuò)，而且很難找。**
4.mybatis自定義sql
當(dāng)我們需要自定義sql的時(shí)候，我們不能把這些也放到mapper文件中。不然，當(dāng)數(shù)據(jù)庫表的字段有更新需要重新生成mapper的時(shí)候，這樣我們自定義的sql不就被覆蓋沒了么！所以我們需要在moviemapper.xml的同級目錄里，新建一個(gè)moviemapperext.xml文件，把自定義的sql放到這里，例子如下：
moviemapperext.xml文件內(nèi)容
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
<?xml version="1.0" encoding="utf-8" ?><!doctype mapper public "-//mybatis.org//dtd mapper 3.0//en" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" ><mapper namespace="com.dameiweb.learn.dao.moviemapper" > <select id="selectbycondition" resultmap="baseresultmap" parametertype="com.dameiweb.learn.dto.movierequest"> select yd_movies.* from yd_movies left join yd_r_movie_countries on yd_movies.id = yd_r_movie_countries.movie_id left join yd_countries cou on yd_r_movie_countries.country_id = cou.id left join yd_r_movie_category on yd_movies.id = yd_r_movie_category.movie_id left join yd_category cat on yd_r_movie_category.category_id = cat.id left join yd_r_movie_actor on yd_movies.id = yd_r_movie_actor.movie_id left join yd_actors a on yd_r_movie_actor.actor_id = a.id where yd_movies.status = 1 <if test="movierequest.title != null"> and yd_movies.title like "%"#{movierequest.title}"%" </if> <if test="movierequest.country != null"> and cou.id = #{movierequest.country} </if> <if test="movierequest.category != null"> and cat.id = #{movierequest.category} </if> <if test="movierequest.year != null"> and year = #{movierequest.year} </if> <if test="movierequest.rate != null"> and rate >= #{movierequest.rate} </if> <if test="movierequest.rate != null"> and rate < (#{movierequest.rate}+1) </if> <if test="movierequest.subtype != null"> and yd_movies.subtype = #{movierequest.subtype} </if> group by yd_movies.id order by updated_at desc, year </select></mapper> |
總結(jié)
以上所述是小編給大家介紹的spring boot整合mybatis并自動(dòng)生成mapper和實(shí)體，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時(shí)回復(fù)大家的。在此也非常感謝大家對服務(wù)器之家網(wǎng)站的支持！
原文鏈接：https://www.ydstudio.net/archives/54.html
