分页工具类 - 风又奈何

分页工具类

  1 /*
  2  * The MIT License (MIT)
  3  *
  4  * Copyright (c) 2014 abel533@gmail.com
  5  *
  6  * Permission is hereby granted, free of charge, to any person obtaining a copy
  7  * of this software and associated documentation files (the "Software"), to deal
  8  * in the Software without restriction, including without limitation the rights
  9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 10  * copies of the Software, and to permit persons to whom the Software is
 11  * furnished to do so, subject to the following conditions:
 12  *
 13  * The above copyright notice and this permission notice shall be included in
 14  * all copies or substantial portions of the Software.
 15  *
 16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 22  * THE SOFTWARE.
 23  */
 24 
 25 package com.github.pagehelper;
 26 
 27 import org.apache.ibatis.executor.Executor;
 28 import org.apache.ibatis.mapping.MappedStatement;
 29 import org.apache.ibatis.plugin.*;
 30 import org.apache.ibatis.session.ResultHandler;
 31 import org.apache.ibatis.session.RowBounds;
 32 
 33 import java.util.Properties;
 34 
 35 /**
 36  * Mybatis - 通用分页拦截器
 37  *
 38  * @author liuzh/abel533/isea533
 39  * @version 3.3.0
 40  *          项目地址 : http://git.oschina.net/free/Mybatis_PageHelper
 41  */
 42 @SuppressWarnings({"rawtypes", "unchecked"})
 43 @Intercepts(@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}))
 44 public class PageHelper implements Interceptor {
 45     //sql工具类
 46     private SqlUtil sqlUtil;
 47 
 48     /**
 49      * 开始分页
 50      *
 51      * @param pageNum  页码
 52      * @param pageSize 每页显示数量
 53      */
 54     public static Page startPage(int pageNum, int pageSize) {
 55         return startPage(pageNum, pageSize, true);
 56     }
 57 
 58     /**
 59      * 开始分页
 60      *
 61      * @param pageNum  页码
 62      * @param pageSize 每页显示数量
 63      * @param orderBy  针对sqlserver - 建议在sql中直接包含order by
 64      */
 65     public static Page startPage(int pageNum, int pageSize, String orderBy) {
 66         return startPage(pageNum, pageSize, true).orderBy(orderBy);
 67     }
 68 
 69     /**
 70      * 开始分页
 71      *
 72      * @param pageNum  页码
 73      * @param pageSize 每页显示数量
 74      * @param count    是否进行count查询
 75      */
 76     public static Page startPage(int pageNum, int pageSize, boolean count) {
 77         return startPage(pageNum, pageSize, count, null);
 78     }
 79 
 80     /**
 81      * 开始分页
 82      *
 83      * @param pageNum    页码
 84      * @param pageSize   每页显示数量
 85      * @param count      是否进行count查询
 86      * @param reasonable 分页合理化,null时用默认配置
 87      */
 88     public static Page startPage(int pageNum, int pageSize, boolean count, Boolean reasonable) {
 89         return startPage(pageNum, pageSize, count, reasonable, null);
 90     }
 91 
 92     /**
 93      * 开始分页
 94      *
 95      * @param pageNum      页码
 96      * @param pageSize     每页显示数量
 97      * @param count        是否进行count查询
 98      * @param reasonable   分页合理化,null时用默认配置
 99      * @param pageSizeZero true且pageSize=0时返回全部结果，false时分页,null时用默认配置
100      */
101     public static Page startPage(int pageNum, int pageSize, boolean count, Boolean reasonable, Boolean pageSizeZero) {
102         Page page = new Page(pageNum, pageSize, count);
103         page.setReasonable(reasonable);
104         page.setPageSizeZero(pageSizeZero);
105         SqlUtil.setLocalPage(page);
106         return page;
107     }
108 
109     /**
110      * 开始分页
111      *
112      * @param params
113      */
114     public static Page startPage(Object params) {
115         Page page = SqlUtil.getPageFromObject(params);
116         SqlUtil.setLocalPage(page);
117         return page;
118     }
119 
120 
121     /**
122      * Mybatis拦截器方法
123      *
124      * @param invocation 拦截器入参
125      * @return 返回执行结果
126      * @throws Throwable 抛出异常
127      */
128     public Object intercept(Invocation invocation) throws Throwable {
129         return sqlUtil.processPage(invocation);
130     }
131 
132     /**
133      * 只拦截Executor
134      *
135      * @param target
136      * @return
137      */
138     public Object plugin(Object target) {
139         if (target instanceof Executor) {
140             return Plugin.wrap(target, this);
141         } else {
142             return target;
143         }
144     }
145 
146     /**
147      * 设置属性值
148      *
149      * @param p 属性值
150      */
151     public void setProperties(Properties p) {
152         //数据库方言
153         String dialect = p.getProperty("dialect");
154         sqlUtil = new SqlUtil(dialect);
155         sqlUtil.setProperties(p);
156     }
157 }

  1 /*
  2  * The MIT License (MIT)
  3  *
  4  * Copyright (c) 2014 abel533@gmail.com
  5  *
  6  * Permission is hereby granted, free of charge, to any person obtaining a copy
  7  * of this software and associated documentation files (the "Software"), to deal
  8  * in the Software without restriction, including without limitation the rights
  9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 10  * copies of the Software, and to permit persons to whom the Software is
 11  * furnished to do so, subject to the following conditions:
 12  *
 13  * The above copyright notice and this permission notice shall be included in
 14  * all copies or substantial portions of the Software.
 15  *
 16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 22  * THE SOFTWARE.
 23  */
 24 
 25 package com.github.pagehelper;
 26 
 27 import java.io.Serializable;
 28 import java.util.List;
 29 
 30 /**
 31  * 对Page<E>结果进行包装
 32  * <p/>
 33  * 新增分页的多项属性，主要参考:http://bbs.csdn.net/topics/360010907
 34  *
 35  * @author liuzh/abel533/isea533
 36  * @version 3.3.0
 37  * @since 3.2.2
 38  * 项目地址 : http://git.oschina.net/free/Mybatis_PageHelper
 39  */
 40 @SuppressWarnings({"rawtypes", "unchecked"})
 41 public class PageInfo<T> implements Serializable {
 42     private static final long serialVersionUID = 1L;
 43     //当前页
 44     private int pageNum;
 45     //每页的数量
 46     private int pageSize;
 47     //当前页的数量
 48     private int size;
 49     //由于startRow和endRow不常用，这里说个具体的用法
 50     //可以在页面中"显示startRow到endRow 共size条数据"
 51 
 52     //当前页面第一个元素在数据库中的行号
 53     private int startRow;
 54     //当前页面最后一个元素在数据库中的行号
 55     private int endRow;
 56     //总记录数
 57     private long total;
 58     //总页数
 59     private int pages;
 60     //结果集
 61     private List<T> list;
 62 
 63     //第一页
 64     private int firstPage;
 65     //前一页
 66     private int prePage;
 67     //下一页
 68     private int nextPage;
 69     //最后一页
 70     private int lastPage;
 71 
 72     //是否为第一页
 73     private boolean isFirstPage = false;
 74     //是否为最后一页
 75     private boolean isLastPage = false;
 76     //是否有前一页
 77     private boolean hasPreviousPage = false;
 78     //是否有下一页
 79     private boolean hasNextPage = false;
 80     //导航页码数
 81     private int navigatePages;
 82     //所有导航页号
 83     private int[] navigatepageNums;
 84 
 85     /**
 86      * 包装Page对象
 87      *
 88      * @param list
 89      */
 90     public PageInfo(List<T> list) {
 91         this(list, 8);
 92     }
 93 
 94     /**
 95      * 包装Page对象
 96      *
 97      * @param list          page结果
 98      * @param navigatePages 页码数量
 99      */
100     public PageInfo(List<T> list, int navigatePages) {
101         if (list instanceof Page) {
102             Page page = (Page) list;
103             this.pageNum = page.getPageNum();
104             this.pageSize = page.getPageSize();
105 
106             this.total = page.getTotal();
107             this.pages = page.getPages();
108             this.list = page;
109             this.size = page.size();
110             //由于结果是>startRow的，所以实际的需要+1
111             if (this.size == 0) {
112                 this.startRow = 0;
113                 this.endRow = 0;
114             } else {
115                 this.startRow = page.getStartRow() + 1;
116                 //计算实际的endRow（最后一页的时候特殊）
117                 this.endRow = this.startRow - 1 + this.size;
118             }
119             this.navigatePages = navigatePages;
120             //计算导航页
121             calcNavigatepageNums();
122             //计算前后页，第一页，最后一页
123             calcPage();
124             //判断页面边界
125             judgePageBoudary();
126         }
127     }
128 
129     /**
130      * 计算导航页
131      */
132     private void calcNavigatepageNums() {
133         //当总页数小于或等于导航页码数时
134         if (pages <= navigatePages) {
135             navigatepageNums = new int[pages];
136             for (int i = 0; i < pages; i++) {
137                 navigatepageNums[i] = i + 1;
138             }
139         } else { //当总页数大于导航页码数时
140             navigatepageNums = new int[navigatePages];
141             int startNum = pageNum - navigatePages / 2;
142             int endNum = pageNum + navigatePages / 2;
143 
144             if (startNum < 1) {
145                 startNum = 1;
146                 //(最前navigatePages页
147                 for (int i = 0; i < navigatePages; i++) {
148                     navigatepageNums[i] = startNum++;
149                 }
150             } else if (endNum > pages) {
151                 endNum = pages;
152                 //最后navigatePages页
153                 for (int i = navigatePages - 1; i >= 0; i--) {
154                     navigatepageNums[i] = endNum--;
155                 }
156             } else {
157                 //所有中间页
158                 for (int i = 0; i < navigatePages; i++) {
159                     navigatepageNums[i] = startNum++;
160                 }
161             }
162         }
163     }
164 
165     /**
166      * 计算前后页，第一页，最后一页
167      */
168     private void calcPage() {
169         if (navigatepageNums != null && navigatepageNums.length > 0) {
170             firstPage = navigatepageNums[0];
171             lastPage = navigatepageNums[navigatepageNums.length - 1];
172             if (pageNum > 1) {
173                 prePage = pageNum - 1;
174             }
175             if (pageNum < pages) {
176                 nextPage = pageNum + 1;
177             }
178         }
179     }
180 
181     /**
182      * 判定页面边界
183      */
184     private void judgePageBoudary() {
185         isFirstPage = pageNum == 1;
186         isLastPage = pageNum == pages;
187         hasPreviousPage = pageNum > 1;
188         hasNextPage = pageNum < pages;
189     }
190 
191     public void setPageNum(int pageNum) {
192         this.pageNum = pageNum;
193     }
194 
195     public int getPageNum() {
196         return pageNum;
197     }
198 
199     public int getPageSize() {
200         return pageSize;
201     }
202 
203     public int getSize() {
204         return size;
205     }
206 
207     public int getStartRow() {
208         return startRow;
209     }
210 
211     public int getEndRow() {
212         return endRow;
213     }
214 
215     public long getTotal() {
216         return total;
217     }
218 
219     public int getPages() {
220         return pages;
221     }
222 
223     public List<T> getList() {
224         return list;
225     }
226 
227     public int getFirstPage() {
228         return firstPage;
229     }
230 
231     public int getPrePage() {
232         return prePage;
233     }
234 
235     public int getNextPage() {
236         return nextPage;
237     }
238 
239     public int getLastPage() {
240         return lastPage;
241     }
242 
243     public boolean isIsFirstPage() {
244         return isFirstPage;
245     }
246 
247     public boolean isIsLastPage() {
248         return isLastPage;
249     }
250 
251     public boolean isHasPreviousPage() {
252         return hasPreviousPage;
253     }
254 
255     public boolean isHasNextPage() {
256         return hasNextPage;
257     }
258 
259     public int getNavigatePages() {
260         return navigatePages;
261     }
262 
263     public int[] getNavigatepageNums() {
264         return navigatepageNums;
265     }
266 
267     @Override
268     public String toString() {
269         final StringBuffer sb = new StringBuffer("PageInfo{");
270         sb.append("pageNum=").append(pageNum);
271         sb.append(", pageSize=").append(pageSize);
272         sb.append(", size=").append(size);
273         sb.append(", startRow=").append(startRow);
274         sb.append(", endRow=").append(endRow);
275         sb.append(", total=").append(total);
276         sb.append(", pages=").append(pages);
277         sb.append(", list=").append(list);
278         sb.append(", firstPage=").append(firstPage);
279         sb.append(", prePage=").append(prePage);
280         sb.append(", nextPage=").append(nextPage);
281         sb.append(", lastPage=").append(lastPage);
282         sb.append(", isFirstPage=").append(isFirstPage);
283         sb.append(", isLastPage=").append(isLastPage);
284         sb.append(", hasPreviousPage=").append(hasPreviousPage);
285         sb.append(", hasNextPage=").append(hasNextPage);
286         sb.append(", navigatePages=").append(navigatePages);
287         sb.append(", navigatepageNums=");
288         if (navigatepageNums == null) sb.append("null");
289         else {
290             sb.append('[');
291             for (int i = 0; i < navigatepageNums.length; ++i)
292                 sb.append(i == 0 ? "" : ", ").append(navigatepageNums[i]);
293             sb.append(']');
294         }
295         sb.append('}');
296         return sb.toString();
297     }
298 }

posted on 2018-11-29 15:30 风又奈何阅读(1182) 评论(0) 编辑收藏举报