pagehelper插件-mybatis

/* * The MIT License (MIT) * * Copyright (c) 2014 abel533@gmail.com * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.github.pagehelper; import org.apache.ibatis.builder.SqlSourceBuilder; import org.apache.ibatis.builder.StaticSqlSource; import org.apache.ibatis.builder.annotation.ProviderSqlSource; import org.apache.ibatis.mapping.*; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.factory.DefaultObjectFactory; import org.apache.ibatis.reflection.factory.ObjectFactory; import org.apache.ibatis.reflection.wrapper.DefaultObjectWrapperFactory; import org.apache.ibatis.reflection.wrapper.ObjectWrapperFactory; import org.apache.ibatis.scripting.xmltags.DynamicContext; import org.apache.ibatis.scripting.xmltags.DynamicSqlSource; import org.apache.ibatis.scripting.xmltags.MixedSqlNode; import org.apache.ibatis.scripting.xmltags.SqlNode; import org.apache.ibatis.session.Configuration; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Mybatis - sql工具，获取分页和count的MappedStatement，设置分页参数 * * @author liuzh/abel533/isea533 * @since 3.3.0 * 项目地址 : http://git.oschina.net/free/Mybatis_PageHelper */ @SuppressWarnings({"rawtypes", "unchecked"}) public class SqlUtil { private static final List<ResultMapping> EMPTY_RESULTMAPPING = new ArrayList<ResultMapping>(0); //分页的id后缀 private static final String SUFFIX_PAGE = "_PageHelper"; //count查询的id后缀 private static final String SUFFIX_COUNT = SUFFIX_PAGE + "_Count"; //第一个分页参数 private static final String PAGEPARAMETER_FIRST = "First" + SUFFIX_PAGE; //第二个分页参数 private static final String PAGEPARAMETER_SECOND = "Second" + SUFFIX_PAGE; private static final String PROVIDER_OBJECT = "_provider_object"; private static final ObjectFactory DEFAULT_OBJECT_FACTORY = new DefaultObjectFactory(); private static final ObjectWrapperFactory DEFAULT_OBJECT_WRAPPER_FACTORY = new DefaultObjectWrapperFactory(); /** * 反射对象，增加对低版本Mybatis的支持 * * @param object 反射对象 * @return */ private static MetaObject forObject(Object object) { return MetaObject.forObject(object, DEFAULT_OBJECT_FACTORY, DEFAULT_OBJECT_WRAPPER_FACTORY); } private SqlUtil.Parser sqlParser; //数据库方言 - 使用枚举限制数据库类型 public enum Dialect { mysql, mariadb, sqlite, oracle, hsqldb, postgresql } /** * 构造方法 * * @param strDialect */ public SqlUtil(String strDialect) { if (strDialect == null || "".equals(strDialect)) { throw new IllegalArgumentException("Mybatis分页插件无法获取dialect参数!"); } try { Dialect dialect = Dialect.valueOf(strDialect); String sqlParserClass = this.getClass().getPackage().getName() + ".SqlParser"; try { //使用SqlParser必须引入jsqlparser-x.x.x.jar Class.forName("net.sf.jsqlparser.statement.select.Select"); sqlParser = (Parser) Class.forName(sqlParserClass).getConstructor(Dialect.class).newInstance(dialect); } catch (Exception e) { //找不到时，不用处理 } if (sqlParser == null) { sqlParser = SimpleParser.newParser(dialect); } } catch (IllegalArgumentException e) { String dialects = null; for (Dialect d : Dialect.values()) { if (dialects == null) { dialects = d.toString(); } else { dialects += "," + d; } } throw new IllegalArgumentException("Mybatis分页插件dialect参数值错误，可选值为[" + dialects + "]"); } } /** * 设置分页参数 * * @param parameterObject * @param page * @return */ public Map setPageParameter(MappedStatement ms, Object parameterObject, Page page) { BoundSql boundSql = ms.getBoundSql(parameterObject); return sqlParser.setPageParameter(ms, parameterObject, boundSql, page); } /** * 处理count查询的MappedStatement * * @param ms * @param sqlSource * @param args */ public void processCountMappedStatement(MappedStatement ms, SqlSource sqlSource, Object[] args) { args[0] = getMappedStatement(ms, sqlSource, args[1], SUFFIX_COUNT); } /** * 处理分页查询的MappedStatement * * @param ms * @param sqlSource * @param page * @param args */ public void processPageMappedStatement(MappedStatement ms, SqlSource sqlSource, Page page, Object[] args) { args[0] = getMappedStatement(ms, sqlSource, args[1], SUFFIX_PAGE); //处理入参 args[1] = setPageParameter((MappedStatement) args[0], args[1], page); } /** * 处理SQL */ public static interface Parser { void isSupportedSql(String sql); String getCountSql(String sql); String getPageSql(String sql); Map setPageParameter(MappedStatement ms, Object parameterObject, BoundSql boundSql, Page page); } public static abstract class SimpleParser implements Parser { public static Parser newParser(Dialect dialect) { Parser parser = null; switch (dialect) { case mysql: case mariadb: case sqlite: parser = new MysqlParser(); break; case oracle: parser = new OracleParser(); break; case hsqldb: parser = new HsqldbParser(); break; case postgresql: default: parser = new PostgreSQLParser(); } return parser; } public void isSupportedSql(String sql) { if (sql.trim().toUpperCase().endsWith("FOR UPDATE")) { throw new RuntimeException("分页插件不支持包含for update的sql"); } } /** * 获取总数sql - 如果要支持其他数据库，修改这里就可以 * * @param sql 原查询sql * @return 返回count查询sql */ public String getCountSql(final String sql) { isSupportedSql(sql); StringBuilder stringBuilder = new StringBuilder(sql.length() + 40); stringBuilder.append("select count(*) from ("); str