Java tutorial
/* * 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.linju.framework.pager; import com.linju.framework.pager.parser.Parser; import com.linju.framework.pager.parser.impl.AbstractParser; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.SqlSource; import org.apache.ibatis.plugin.Invocation; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.SystemMetaObject; import org.apache.ibatis.session.RowBounds; import java.lang.reflect.Method; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Properties; /** * Mybatis - sql?countMappedStatement? * * @author liuzh/abel533/isea533 * @since 3.6.0 * ? : http://git.oschina.net/free/Mybatis_PageHelper */ @SuppressWarnings({ "rawtypes", "unchecked" }) public class SqlUtil implements Constant { private static final ThreadLocal<Page> LOCAL_PAGE = new ThreadLocal<Page>(); //RowBounds?offsetPageNum - ? private boolean offsetAsPageNum = false; //RowBounds?count - ? private boolean rowBoundsWithCount = false; //truepagesize0RowBoundslimit=0? private boolean pageSizeZero = false; //?? private boolean reasonable = false; //params? private static Map<String, String> PARAMS = new HashMap<String, String>(5); //request? private static Boolean hasRequest; private static Class<?> requestClass; private static Method getParameterMap; static { try { requestClass = Class.forName("javax.servlet.ServletRequest"); getParameterMap = requestClass.getMethod("getParameterMap", new Class[] {}); hasRequest = true; } catch (Exception e) { hasRequest = false; } } //?parser private Parser parser; //?MS private MSUtils msUtils; //? private Dialect dialect; /** * * * @param strDialect */ public SqlUtil(String strDialect) { if (strDialect == null || "".equals(strDialect)) { throw new IllegalArgumentException("Mybatis??dialect?!"); } dialect = Dialect.of(strDialect); parser = AbstractParser.newParser(dialect); msUtils = new MSUtils(parser); } public static void setLocalPage(Page page) { LOCAL_PAGE.set(page); } /** * ?Page? * * @return */ public static Page getLocalPage() { return LOCAL_PAGE.get(); } /** * ?? */ public static void clearLocalPage() { LOCAL_PAGE.remove(); } /** * ?? * * @param params RowBounds? * @return Page */ public Page getPage(Object params) { Page page = getLocalPage(); if (page == null) { if (params instanceof RowBounds) { RowBounds rowBounds = (RowBounds) params; if (offsetAsPageNum) { page = new Page(rowBounds.getOffset(), rowBounds.getLimit(), rowBoundsWithCount); } else { page = new Page(rowBounds, rowBoundsWithCount); //offsetAsPageNum=falsePageNum?reasonablefalse page.setReasonable(false); } } else { page = getPageFromObject(params); } setLocalPage(page); } //?? if (page.getReasonable() == null) { page.setReasonable(reasonable); } //truepagesize0RowBoundslimit=0? if (page.getPageSizeZero() == null) { page.setPageSizeZero(pageSizeZero); } return page; } /** * ?? * * @param params * @return */ public static Page getPageFromObject(Object params) { int pageNum; int pageSize; MetaObject paramsObject = null; if (params == null) { throw new NullPointerException("?params?!"); } if (hasRequest && requestClass.isAssignableFrom(params.getClass())) { try { paramsObject = SystemMetaObject.forObject(getParameterMap.invoke(params, new Object[] {})); } catch (Exception e) { // } } else { paramsObject = SystemMetaObject.forObject(params); } if (paramsObject == null) { throw new NullPointerException("?params?!"); } try { pageNum = Integer.parseInt(String.valueOf(getParamValue(paramsObject, "pageNum", true))); pageSize = Integer.parseInt(String.valueOf(getParamValue(paramsObject, "pageSize", true))); } catch (NumberFormatException e) { throw new IllegalArgumentException("???!"); } Object _count = getParamValue(paramsObject, "count", false); boolean count = true; if (_count != null) { count = Boolean.valueOf(String.valueOf(_count)); } Page page = new Page(pageNum, pageSize, count); Object reasonable = getParamValue(paramsObject, "reasonable", false); if (reasonable != null) { page.setReasonable(Boolean.valueOf(String.valueOf(reasonable))); } Object pageSizeZero = getParamValue(paramsObject, "pageSizeZero", false); if (pageSizeZero != null) { page.setPageSizeZero(Boolean.valueOf(String.valueOf(pageSizeZero))); } return page; } /** * ?? * * @param paramsObject * @param paramName * @param required * @return */ public static Object getParamValue(MetaObject paramsObject, String paramName, boolean required) { Object value = null; if (paramsObject.hasGetter(PARAMS.get(paramName))) { value = paramsObject.getValue(PARAMS.get(paramName)); } if (required && value == null) { throw new RuntimeException("??:" + PARAMS.get(paramName)); } return value; } /** * Mybatis * * @param invocation ? * @return * @throws Throwable */ public Object processPage(Invocation invocation) throws Throwable { try { Object result = _processPage(invocation); return result; } finally { clearLocalPage(); } } /** * Mybatis * * @param invocation ? * @return * @throws Throwable */ private Object _processPage(Invocation invocation) throws Throwable { final Object[] args = invocation.getArgs(); RowBounds rowBounds = (RowBounds) args[2]; if (SqlUtil.getLocalPage() == null && rowBounds == RowBounds.DEFAULT) { return invocation.proceed(); } else { //RowBounds-?Mybatis args[2] = RowBounds.DEFAULT; //? Page page = getPage(rowBounds); //pageSizeZero if ((page.getPageSizeZero() != null && page.getPageSizeZero()) && page.getPageSize() == 0) { //? Object result = invocation.proceed(); //? page.addAll((List) result); // page.setPageNum(1); //?pageSize=total page.setPageSize(page.size()); //??total page.setTotal(page.size()); //?Page - ??? return page; } //?ms MappedStatement ms = (MappedStatement) args[0]; SqlSource sqlSource = ms.getSqlSource(); //?total??count if (page.isCount()) { //?MappedStatement?qs msUtils.processCountMappedStatement(ms, sqlSource, args); // Object result = invocation.proceed(); // page.setTotal((Integer) ((List) result).get(0)); if (page.getTotal() == 0) { return page; } } //pageSize>0pageSize<=0???count if (page.getPageSize() > 0 && ((rowBounds == RowBounds.DEFAULT && page.getPageNum() > 0) || rowBounds != RowBounds.DEFAULT)) { //?MappedStatement?qs msUtils.processPageMappedStatement(ms, sqlSource, page, args); // Object result = invocation.proceed(); //? page.addAll((List) result); } // return page; } } public void setProperties(Properties p) { //offsetPageNum String offsetAsPageNum = p.getProperty("offsetAsPageNum"); this.offsetAsPageNum = Boolean.parseBoolean(offsetAsPageNum); //RowBounds???count String rowBoundsWithCount = p.getProperty("rowBoundsWithCount"); this.rowBoundsWithCount = Boolean.parseBoolean(rowBoundsWithCount); //truepagesize0RowBoundslimit=0? String pageSizeZero = p.getProperty("pageSizeZero"); this.pageSizeZero = Boolean.parseBoolean(pageSizeZero); //??true?????false?? String reasonable = p.getProperty("reasonable"); this.reasonable = Boolean.parseBoolean(reasonable); //offsetAsPageNum=false? //? PARAMS.put("pageNum", "pageNum"); PARAMS.put("pageSize", "pageSize"); PARAMS.put("count", "countSql"); PARAMS.put("reasonable", "reasonable"); PARAMS.put("pageSizeZero", "pageSizeZero"); String params = p.getProperty("params"); if (params != null && params.length() > 0) { String[] ps = params.split("[;|,|&]"); for (String s : ps) { String[] ss = s.split("[=|:]"); if (ss.length == 2) { PARAMS.put(ss[0], ss[1]); } } } } /** * [?]countsql * * @param dialect ? * @param originalSql sql */ public static void testSql(String dialect, String originalSql) { testSql(Dialect.of(dialect), originalSql); } /** * [?]countsql * * @param dialect ? * @param originalSql sql */ public static void testSql(Dialect dialect, String originalSql) { Parser parser = AbstractParser.newParser(dialect); if (dialect == Dialect.sqlserver) { setLocalPage(new Page(1, 10)); } String countSql = parser.getCountSql(originalSql); System.out.println(countSql); String pageSql = parser.getPageSql(originalSql); System.out.println(pageSql); if (dialect == Dialect.sqlserver) { clearLocalPage(); } } }