Mybatis分页

参考网上各位牛人的帖子，终于实现了Mybatis的物理分页。

贴出来备用

 

ApplicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- -->
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
	xsi:schemaLocation="
	http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
	http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
	http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"
	default-lazy-init="true">
	<bean class="com.nechx.util.SpringContextUtil" lazy-init="false" />
	<context:property-placeholder location="classpath*:conf/core.properties" />
	<context:component-scan base-package="com.nechx.*" />
	<!-- 数据源配置,使用dbcp数据库连接池 -->

	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
		destroy-method="close">
		<property name="driverClassName" value="${jdbc.driverClassName}" />
		<property name="url" value="${jdbc.url}" />
		<property name="username" value="${jdbc.username}" />
		<property name="password" value="${jdbc.password}" />
		<property name="maxActive" value="10" />
		<property name="maxIdle" value="30" />
		<property name="maxWait" value="10000" />
	</bean>
	<!--  创建  SqlSessionFactoryBean-->
	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<property name="dataSource" ref="dataSource" />
		<property name="configLocation" value="classpath:mybatis/sqlMapConfig.xml" />
		<property name="mapperLocations" value="classpath:com/spm/mapper/xml/*.xml" /> 
	</bean>
	
	<!--  创建  SqlSessionTemplate-->
	<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
		<constructor-arg index="0" ref="sqlSessionFactory" />
	</bean>

	<!-- 
		创建 MapperScannerConfigurer 
		MapperScannerConfigurer会查 找 类 路 径 下 的 映 射 器 并 自 动 将 它 们 创 建 成 MapperFactoryBean。
		basePackage 属性是让你为映射器接口文件设置基本的包路径。 
		可以使用分号或逗号 作为分隔符设置多于一个的包路径。
		每个映射器将会在指定的包路径中递归地被搜索到。 
	-->
	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="com.spm.mapper" />
	</bean>
	
	<bean id="transactionManager"
		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource" />
	</bean>

	<!-- 使用annotation定义事务 transaction-manager="transactionManager" proxy-target-class="true" -->
	<!-- <tx:annotation-driven proxy-target-class="true"/> -->
	<bean id="appConfig" class="com.spm.common.ApplicationConfig">
		<property name="filePath" value="${app.fileBasePath}" />
		<property name="fileServer" value="${app.fileServer}" />
	</bean>
	<!-- <import resource="classpath*:spring/log4j.xml"/> -->
</beans>

 

 

sqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8"  standalone="no"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<plugins>
		<plugin interceptor="com.spm.interceptor.PaginationInterceptor">
			<property name="dialect" value="oracle" />
			<property name="pageSqlId" value=".*selectPage.*"/>
		</plugin>
	</plugins>
</configuration>

 

 

PaginationInterceptor.java

@Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class }) })
public class PaginationInterceptor implements Interceptor {
	public static final ObjectFactory DEFAULT_OBJECT_FACTORY = new DefaultObjectFactory();
	public static final ObjectWrapperFactory DEFAULT_OBJECT_WRAPPER_FACTORY = 
                                                         new DefaultObjectWrapperFactory();
	
	private static Dialect dialect = null; // SQL方言
	private static String pageSqlId = "";  // 要拦截的SQL语句名正则
	
	private final static Log log = LogFactory.getLog(PaginationInterceptor.class);

	public Object intercept(Invocation invocation) throws Throwable {
		StatementHandler statementHandler = null;
		RoutingStatementHandler rsh = (RoutingStatementHandler) invocation.getTarget();
                BaseStatementHandler delegate = 
                     (BaseStatementHandler) ReflectHelper.getValueByFieldName(rsh, "delegate");
		MappedStatement mappedStatement = 
                      (MappedStatement)ReflectHelper.getValueByFieldName(delegate, 
                                                                 "mappedStatement"); 
                // 对SQL方法名做匹配，若包含指定的字符串，则拦截，进行分页操作
		if (mappedStatement.getId().matches(pageSqlId)) {
			statementHandler = (StatementHandler) invocation.getTarget();
			BoundSql boundSql = statementHandler.getBoundSql();
			MetaObject metaStatementHandler = 
                        MetaObject.forObject(statementHandler, 
                                                 DEFAULT_OBJECT_FACTORY,
                                                 DEFAULT_OBJECT_WRAPPER_FACTORY);
			RowBounds rowBounds = 
                                (RowBounds) metaStatementHandler.getValue("delegate.rowBounds");

			if (rowBounds == null || rowBounds == RowBounds.DEFAULT) {
				return invocation.proceed();
			}

			String originalSql = 
                              (String) metaStatementHandler.getValue("delegate.boundSql.sql");
			metaStatementHandler.setValue("delegate.boundSql.sql", 
                                                        dialect.getLimitString(originalSql,
                                            rowBounds.getOffset(),rowBounds.getLimit()));			     metaStatementHandler.setValue("delegate.rowBounds.offset",RowBounds.NO_ROW_OFFSET);		metaStatementHandler.setValue("delegate.rowBounds.limit",RowBounds.NO_ROW_LIMIT);

			if (log.isDebugEnabled()) {
				log.debug("生成分页SQL : " + boundSql.getSql());
			}

		} 
		return invocation.proceed();
	}

	public Object plugin(Object target) {
		return Plugin.wrap(target, this);
	}
        // 通过读取properties，对类中的两个属性进行赋值
	public void setProperties(Properties properties) {
                 
		String databaseTypeStr = properties.getProperty("dialect");
		if (Tools.isEmpty(databaseTypeStr)) {
			try {
				throw new PropertyException("dialect property is not found!");
			} catch (PropertyException e) {
				e.printStackTrace();
			}
		} else {
			Dialect.Type databaseType = Dialect.Type.valueOf(databaseTypeStr.toUpperCase());
			switch (databaseType) {
			case MYSQL:
				dialect = new MySql5Dialect();
				break;
			case ORACLE:
				dialect = new OracleDialect();
				break;
			}
		}
		pageSqlId = properties.getProperty("pageSqlId");
		if (Tools.isEmpty(pageSqlId)) {
			try {
				throw new PropertyException("pageSqlId property is not found!");
			} catch (PropertyException e) {
				e.printStackTrace();
			}
		}
	}

}

 

ReflectHelper.java

/**
 * @author Administrator
 *	反射工具
 */
public class ReflectHelper {
	/**
	 * 获取obj对象fieldName的Field
	 * @param obj
	 * @param fieldName
	 * @return
	 */
	public static Field getFieldByFieldName(Object obj, String fieldName) {
		for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
			try {
				return superClass.getDeclaredField(fieldName);
			} catch (NoSuchFieldException e) {
			}
		}
		return null;
	}

	/**
	 * 获取obj对象fieldName的属性值
	 * @param obj
	 * @param fieldName
	 * @return
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static Object getValueByFieldName(Object obj, String fieldName)
			throws SecurityException, NoSuchFieldException,
			IllegalArgumentException, IllegalAccessException {
		Field field = getFieldByFieldName(obj, fieldName);
		Object value = null;
		if(field!=null){
			if (field.isAccessible()) {
				value = field.get(obj);
			} else {
				field.setAccessible(true);
				value = field.get(obj);
				field.setAccessible(false);
			}
		}
		return value;
	}

	/**
	 * 设置obj对象fieldName的属性值
	 * @param obj
	 * @param fieldName
	 * @param value
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 */
	public static void setValueByFieldName(Object obj, String fieldName,
			Object value) throws SecurityException, NoSuchFieldException,
			IllegalArgumentException, IllegalAccessException {
		Field field = obj.getClass().getField(fieldName);
				//.getDeclaredField(fieldName);
		if (field.isAccessible()) {
			field.set(obj, value);
		} else {
			field.setAccessible(true);
			field.set(obj, value);
			field.setAccessible(false);
		}
	}
	
	public static void setValueByPrivateFieldName(Object obj, String fieldName,
			Object value) throws SecurityException, NoSuchFieldException,
			IllegalArgumentException, IllegalAccessException {
		Field field = obj.getClass().getDeclaredField(fieldName);
		if (field.isAccessible()) {
			field.set(obj, value);
		} else {
			field.setAccessible(true);
			field.set(obj, value);
			field.setAccessible(false);
		}
	}
}