目录
[TOC]
前言
最近在写自己的个人博客系统，框架采用 SpringMVC、Spring4.0、Spring Data/JPA 组合，本博客就文档归档功能在 Spring Data JPA 框架下是如何实现的进行记录。 现在可以 star(收藏)，watch(关注)，但是还在开发中，所以还是还在先别下载 项目 github： https://github.com/u014427391/myblog
文章信息设计
数据暂时这样设计，仅供学习参考，对于文章评论回复，栏目之间的关联还没设计，不过本博客的目的是记录文档归档功能的实现，这个并不会影响
VO 类：全部采用注解，注意因为我数据库表名为 article，所以不需要写 @Table 注解，表名为其它的话，就需要自己添加 @Table 注解了
package net.myblog.entity;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
/**
* 博客系统文章信息的实体类
* @author Nicky
*/
@Entity
public class Article {
/** 文章 Id，自增**/
private int articleId;
/** 文章名称**/
private String articleName;
/** 文章发布时间**/
private Date articleTime;
/** 图片路径，测试**/
private String imgPath;
/** 文章内容**/
private String articleContent;
/** 查看人数**/
private int articleClick;
/** 是否博主推荐。0 为否； 1 为是**/
private int articleSupport;
/** 是否置顶。0 为； 1 为是**/
private int articleUp;
/** 文章类别。0 为私有，1 为公开，2 为仅好友查看**/
private int articleType;
@GeneratedValue
@Id
public int getArticleId() {
return articleId;
}
public void setArticleId(int articleId) {
this.articleId = articleId;
}
@Column(length=100, nullable=false)
public String getArticleName() {
return articleName;
}
public void setArticleName(String articleName) {
this.articleName = articleName;
}
@Temporal(TemporalType.DATE)
@Column(nullable=false, updatable=false)
public Date getArticleTime() {
return articleTime;
}
public void setArticleTime(Date articleTime) {
this.articleTime = articleTime;
}
@Column(length=100)
public String getImgPath() {
return imgPath;
}
public void setImgPath(String imgPath) {
this.imgPath = imgPath;
}
@Column(nullable=false)
public String getArticleContent() {
return articleContent;
}
public void setArticleContent(String articleContent) {
this.articleContent = articleContent;
}
public int getArticleClick() {
return articleClick;
}
public void setArticleClick(int articleClick) {
this.articleClick = articleClick;
}
public int getArticleSupport() {
return articleSupport;
}
public void setArticleSupport(int articleSupport) {
this.articleSupport = articleSupport;
}
public int getArticleUp() {
return articleUp;
}
public void setArticleUp(int articleUp) {
this.articleUp = articleUp;
}
@Column(nullable=false)
public int getArticleType() {
return articleType;
}
public void setArticleType(int articleType) {
this.articleType = articleType;
}
}
代码实现步骤
文章表里有很多数据，要按照年月获取文章进行归档的话，我们可以使用如下 SQL 对数据进行分组
SELECT YEAR(articleTime) AS 'year',MONTH(articleTime) AS 'month',COUNT(*) AS 'count' FROM article
GROUP BY YEAR(articleTime) DESC,MONTH(articleTime);
然后编写数据库层的 Repository 类，类实现 Spring Data JPA 提供的接口
package net.myblog.repository;
import java.util.Date;
import java.util.List;
import net.myblog.entity.Article;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
public interface ArticleRepository extends PagingAndSortingRepository<Article,Integer>{
/**
* 文章归档信息获取
* @return
*/
@Query(value="select year(a.articleTime) as year,month(a.articleTime) as month,"
+ "count(a) as count from Article a group by year(a.articleTime),month(a.articleTime)",
countQuery="select count(1) from (select count(1) from Article a group by year(a.articleTime),month(a.articleTime))")
public List<Object[]> findArticleGroupByTime();
}
然后在 Service 类，用 @Autowired 注解调用
package net.myblog.service;
import java.util.Date;
import java.util.List;
import net.myblog.entity.Article;
import net.myblog.repository.ArticleRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
@Service
public class ArticleService {
@Autowired ArticleRepository articleRepository;
/**
* 文章归档信息获取
* @return
*/
@Transactional
public List<Object[]> findArticleGroupByTime(){
return articleRepository.findArticleGroupByTime();
}
}
然后在 Controller 里调用，用的是 SpringMVC 框架
package net.myblog.web.controller;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.myblog.service.ArticleService;
import net.sf.json.JSONArray;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class BlogIndexController extends BaseController{
@Autowired
ArticleService articleService;
/**
* 访问博客主页
* @return
*/
@RequestMapping(value="/toblog",produces="text/html;charset=UTF-8")
public ModelAndView toBlog(HttpServletRequest request, HttpServletResponse response, Model model)throws ClassNotFoundException{
//获取归档文章信息
List<Object[]> archiveArticles = articleService.findArticleGroupByTime();
model.addAttribute("archiveArticles", archiveArticles);
mv.setViewName("myblog/frame/index");
return mv;
}
}
在 JSP 页面调用显示：
<h2><p>文章归档</p></h2>
<ul class="news">
<c:choose>
<c:when test="${not empty archiveArticles }">
<c:forEach items="${archiveArticles }" var="ac">
<li><a href="getArchiveArticles.do?yearmonth=${ac[0]}-${ac[1]}">
${ac[0]}年${ac[1]}月(${ac[2] })</a></li>
</c:forEach>
</c:when>
<c:otherwise>
<li><a href="#">没有相关数据</a></li>
</c:otherwise>
</c:choose>
</ul>
效果如图所示：
文档归档信息查询
然后介绍点击文档归档信息后，获取文章信息的实现，其实也就是按年月查询文档信息
在 Repository 类里添加方法：
/**
* 按月份获取文章信息
* @param month
* 月份数
* @return
*/
@Query("from Article a where date_format(a.articleTime,'%Y%m')=date_format((:yearmonth),'%Y%m') "
+ "order by articleTime desc")
public List<Article> findArticleByMonth(@Param("yearmonth")Date yearmonth);
Service 类里调用：
/**
* 按月份获取文章信息
* @param month
* @return
*/
@Transactional
public List<Article> findArticleByMonth(Date month){
return articleRepository.findArticleByMonth(month);
}
在 JSP 页面写入，getArchiveArticles.do 就是要访问的 url，传入 yearmonth 参数就可以
<h2><p>文章归档</p></h2>
<ul class="news">
<c:choose>
<c:when test="${not empty archiveArticles }">
<c:forEach items="${archiveArticles }" var="ac">
<li><a href="getArchiveArticles.do?yearmonth=${ac[0]}-${ac[1]}">
${ac[0]}年${ac[1]}月(${ac[2] })</a></li>
</c:forEach>
</c:when>
<c:otherwise>
<li><a href="#">没有相关数据</a></li>
</c:otherwise>
</c:choose>
</ul>
在 Controller 类里进行处理：
@RequestMapping("/getArchiveArticles")
public ModelAndView getArticleByMonth(HttpServletRequest request){
String yearMonthString = request.getParameter("yearmonth");
System.out.println("month:"+yearMonthString);
ModelAndView mv = this.getModelAndView();
Date yearmonth = DateUtils.parse("yyyy-MM", yearMonthString);
List<Article> articles = articleService.findArticleByMonth(yearmonth);
mv.addObject("articles", articles);
mv.setViewName("myblog/article/archive_articles");
return mv;
}
附录(工具类、公共类代码)
DateUtils.java、BaseController.java 类 DateUtil.java
package net.myblog.utils;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import net.myblog.core.Constants;
public class DateUtils {
public static String formatDate(Date date) throws ParseException{
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return dateFormat.format(date);
}
/**
* 解析日期，注:此处为严格模式解析，即 20151809 这样的日期会解析错误
*
* @param pattern
* @param date
* @return
*/
public static Date parse(String pattern, String date){
return parse(pattern, date, Constants.LOCALE_CHINA);
}
/**
* 解析日期，注:此处为严格模式解析，即 20151809 这样的日期会解析错误
*
* @param pattern
* @param date
* @param locale
* @return
*/
public static Date parse(String pattern, String date, Locale locale){
SimpleDateFormat format = new SimpleDateFormat(pattern, locale);
format.setLenient(false);
Date result = null;
try{
result = format.parse(date);
}catch(Exception e){
e.printStackTrace();
}
return result;
}
}
BaseController.java:
package net.myblog.web.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.ModelAndView;
public class BaseController {
/**
* 得到 request 对象
*/
public HttpServletRequest getRequest() {
HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
return request;
}
/**
* 得到 ModelAndView
*/
public ModelAndView getModelAndView(){
return new ModelAndView();
}
}
我来吐槽下 Spring data jpa 几点。 
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