springboot主張用java config代替xml配置，但在大部分博文中依然用的是xml配置講解，很少講解javaConfig的內容，我這裏記錄下自己用java config配置mybatis。
pom.xml就不多說了，日常引入
mybatis-spring-boot-starter
這個當然也可以自動加載mybatis的配置，但是在一般大項目中，自動的那些默認配置就很難滿足了。
mybatis javaConfig如下：
@Configuration
@ConfigurationProperties(prefix = "mybatis")
@PropertySource("application-mybatis.yml")
public class MyBatisConfig {
private static final Logger logger = Logger.getLogger(MyBatisConfig.class);
// @Autowired
// private Environment env;
@Autowired
private DataSource druidDataSource;
@Value("${mapperLocations}")
private String mapperLocations;
@Value("${default-statement-timeout}")
private int dst;
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception{
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations));
logger.info("sqlSessionFactory:--->mybatis.mapperLocation:" + mapperLocations );
sqlSessionFactoryBean.setDataSource(druidDataSource);
org.apache.ibatis.session.Configuration cfg = new org.apache.ibatis.session.Configuration();//configuration
cfg.setDefaultStatementTimeout(dst);//設置相關參數，我這裏就只用了一個
logger.info("sqlSessionFactoryBean:-->" + sqlSessionFactoryBean.getObject());
logger.info("default-statement-timeout:" + dst);
sqlSessionFactoryBean.setConfiguration(cfg);
return sqlSessionFactoryBean.getObject();
}相關configuration參數如下：
settings
These are extremely important tweaks that modify the way that MyBatis behaves at runtime. The following table describes the settings, their meanings and their default values.
| Setting | Description | Valid Values | Default |
|---|---|---|---|
| cacheEnabled | Globally enables or disables any caches configured in any mapper under this configuration. | true | false | true |
| lazyLoadingEnabled | Globally enables or disables lazy loading. When enabled, all relations will be lazily loaded. This value can be superseded for an specific relation by using the fetchType attribute on it. | true | false | false |
| aggressiveLazyLoading | When enabled, any method call will load all the lazy properties of the object. Otherwise, each property is loaded on demand (see also lazyLoadTriggerMethods). | true | false | false (true in ≤3.4.1) |
| multipleResultSetsEnabled | Allows or disallows multiple ResultSets to be returned from a single statement (compatible driver required). | true | false | true |
| useColumnLabel | Uses the column label instead of the column name. Different drivers behave differently in this respect. Refer to the driver documentation, or test out both modes to determine how your driver behaves. | true | false | true |
| useGeneratedKeys | Allows JDBC support for generated keys. A compatible driver is required. This setting forces generated keys to be used if set to true, as some drivers deny compatibility but still work (e.g. Derby). | true | false | False |
| autoMappingBehavior | Specifies if and how MyBatis should automatically map columns to fields/properties. NONE disables auto-mapping. PARTIAL will only auto-map results with no nested result mappings defined inside. FULL will auto-map result mappings of any complexity (containing nested or otherwise). | NONE, PARTIAL, FULL | PARTIAL |
| autoMappingUnknownColumnBehavior | Specify the behavior when detects an unknown column (or unknown property type) of automatic mapping target.
| NONE, WARNING, FAILING | NONE |
| defaultExecutorType | Configures the default executor. SIMPLE executor does nothing special. REUSE executor reuses prepared statements. BATCH executor reuses statements and batches updates. | SIMPLE REUSE BATCH | SIMPLE |
| defaultStatementTimeout | Sets the number of seconds the driver will wait for a response from the database. | Any positive integer | Not Set (null) |
| defaultFetchSize | Sets the driver a hint as to control fetching size for return results. This parameter value can be override by a query setting. | Any positive integer | Not Set (null) |
| safeRowBoundsEnabled | Allows using RowBounds on nested statements. If allow, set the false. | true | false | False |
| safeResultHandlerEnabled | Allows using ResultHandler on nested statements. If allow, set the false. | true | false | True |
| mapUnderscoreToCamelCase | Enables automatic mapping from classic database column names A_COLUMN to camel case classic Java property names aColumn. | true | false | False |
| localCacheScope | MyBatis uses local cache to prevent circular references and speed up repeated nested queries. By default (SESSION) all queries executed during a session are cached. If localCacheScope=STATEMENT local session will be used just for statement execution, no data will be shared between two different calls to the same SqlSession. | SESSION | STATEMENT | SESSION |
| jdbcTypeForNull | Specifies the JDBC type for null values when no specific JDBC type was provided for the parameter. Some drivers require specifying the column JDBC type but others work with generic values like NULL, VARCHAR or OTHER. | JdbcType enumeration. Most common are: NULL, VARCHAR and OTHER | OTHER |
| lazyLoadTriggerMethods | Specifies which Object's methods trigger a lazy load | A method name list separated by commas | equals,clone,hashCode,toString |
| defaultScriptingLanguage | Specifies the language used by default for dynamic SQL generation. | A type alias or fully qualified class name. | org.apache.ibatis.scripting.xmltags.XMLLanguageDriver |
| defaultEnumTypeHandler | Specifies the TypeHandler used by default for Enum. (Since: 3.4.5) | A type alias or fully qualified class name. | org.apache.ibatis.type.EnumTypeHandler |
| callSettersOnNulls | Specifies if setters or map's put method will be called when a retrieved value is null. It is useful when you rely on Map.keySet() or null value initialization. Note primitives such as (int,boolean,etc.) will not be set to null. | true | false | false |
| returnInstanceForEmptyRow | MyBatis, by default, returns null when all the columns of a returned row are NULL. When this setting is enabled, MyBatis returns an empty instance instead. Note that it is also applied to nested results (i.e. collectioin and association). Since: 3.4.2 | true | false | false |
| logPrefix | Specifies the prefix string that MyBatis will add to the logger names. | Any String | Not set |
| logImpl | Specifies which logging implementation MyBatis should use. If this setting is not present logging implementation will be autodiscovered. | SLF4J | LOG4J | LOG4J2 | JDK_LOGGING | COMMONS_LOGGING | STDOUT_LOGGING | NO_LOGGING | Not set |
| proxyFactory | Specifies the proxy tool that MyBatis will use for creating lazy loading capable objects. | CGLIB | JAVASSIST | JAVASSIST (MyBatis 3.3 or above) |
| vfsImpl | Specifies VFS implementations | Fully qualified class names of custom VFS implementation separated by commas. | Not set |
| useActualParamName | Allow referencing statement parameters by their actual names declared in the method signature. To use this feature, your project must be compiled in Java 8 with -parameters option. (Since: 3.4.1) | true | false | true |
| configurationFactory | Specifies the class that provides an instance of Configuration. The returned Configuration instance is used to load lazy properties of deserialized objects. This class must have a method with a signature static Configuration getConfiguration(). (Since: 3.2.3) |
至於我的application-mybatis.yml配置文件如何弄，如下：
mybatis:
mapperLocations: classpath*:mapper*/*.xml
default-statement-timeout: 30關於相關資料的查找：
http://www.mybatis.org/mybatis-3/configuration.html#settings
http://www.mybatis.org/spring/apidocs/reference/org/mybatis/spring/package-summary.html