Springboot如何使用mybatis實現攔截SQL分頁
阿新 • • 發佈:2020-06-19
新建一個類MyPageInterceptor.java(注意在springboot中要添加註解@Component)
package com.grand.p1upgrade.mapper.test; import java.sql.Connection; import java.util.Map; import java.util.Properties; import org.apache.ibatis.executor.parameter.ParameterHandler; import org.apache.ibatis.executor.statement.StatementHandler; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.plugin.Interceptor; import org.apache.ibatis.plugin.Intercepts; import org.apache.ibatis.plugin.Invocation; import org.apache.ibatis.plugin.Plugin; import org.apache.ibatis.plugin.Signature; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.SystemMetaObject; import org.springframework.stereotype.Component; @Component @Intercepts({@Signature(type=StatementHandler.class,method="prepare",args={Connection.class,Integer.class})}) public class MyPageInterceptor implements Interceptor { private int page; private int size; @SuppressWarnings("unused") private String dbType; @SuppressWarnings("unchecked") @Override public Object intercept(Invocation invocation) throws Throwable { System.out.println("plugin is running..."); StatementHandler statementHandler = (StatementHandler)invocation.getTarget(); MetaObject metaObject = SystemMetaObject.forObject(statementHandler); while(metaObject.hasGetter("h")){ Object object = metaObject.getValue("h"); metaObject = SystemMetaObject.forObject(object); } while(metaObject.hasGetter("target")){ Object object = metaObject.getValue("target"); metaObject = SystemMetaObject.forObject(object); } MappedStatement mappedStatement = (MappedStatement)metaObject.getValue("delegate.mappedStatement"); String mapId = mappedStatement.getId(); if(mapId.matches(".+ByPager$")){ ParameterHandler parameterHandler = (ParameterHandler)metaObject.getValue("delegate.parameterHandler"); Map<String,Object> params = (Map<String,Object>)parameterHandler.getParameterObject(); page = (int)params.get("page"); size = (int)params.get("size"); String sql = (String) metaObject.getValue("delegate.boundSql.sql"); sql += " limit "+(page-1)*size +","+size; metaObject.setValue("delegate.boundSql.sql",sql); } return invocation.proceed(); } @Override public Object plugin(Object target) { return Plugin.wrap(target,this); } @Override public void setProperties(Properties properties) { String limit = properties.getProperty("limit","10"); this.page = Integer.parseInt(limit); this.dbType = properties.getProperty("dbType","mysql"); } }
新增測試TestMapper.java
package com.grand.p1upgrade.mapper.test; import java.util.List; import java.util.Map; import org.apache.ibatis.annotations.Mapper; @Mapper public interface TestMapper { public List<Map<String,Object>> findByPager(Map<String,Object> params); public long count(); }
TestMapper.xml
<?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.grand.p1upgrade.mapper.test.TestMapper"> <select id="findByPager" resultType="java.util.HashMap"> select * from p1project.sys_user </select> <select id="count" resultType="long"> select count(1) from p1project.sys_user </select> </mapper>
在呼叫TestMapper.findByPager傳遞引數的時候將page和size傳入即可
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。