springboot对jpa的支持
springboot对jpa的支持
JPA简介
JPA（Java Persistence API)是SUN官方推出的Java持久化规范，它为Java开发人员提供了一种对象/关联映射工具来管理Java应用中的关系数据。它的出现主要是为了简化现有的持久化开发工作和整合ORM技术，结束现在Hibernate，TopLink，JDO等ORM框架各自为营的局面。
pom依赖
org.springframework.boot
spring-boot-starter-data-jpa
导入jpa所需配置文件
spring:
jpa:
hibernate:
ddl-auto: update
show-sql: true
一但字段有了变化，它能自动帮我们补全数据库
@Entity
@Table(name = "t_springboot_book")
@Data
public class HBook {
@Id
@GeneratedValue
private Integer bid;
@Column(length = 100)
private String bname;
@Column
private double price;
}
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.2.1.RELEASE
com.lqx
springboot3
0.0.1-SNAPSHOT
springboot3
Demo project for Spring Boot
1.8
5.1.44
org.springframework.boot
spring-boot-starter-data-jdbc
org.springframework.boot
spring-boot-starter-data-jpa
org.springframework.boot
spring-boot-starter-thymeleaf
org.springframework.boot
spring-boot-starter-web
mysql
mysql-connector-java
${mysql.version}
runtime
org.projectlombok
lombok
true
org.springframework.boot
spring-boot-starter-test
test
org.junit.vintage
junit-vintage-engine
com.alibaba
druid-spring-boot-starter
1.1.10
commons-fileupload
commons-fileupload
1.3.1
org.springframework
spring-aspects
org.springframework.boot
spring-boot-maven-plugin
MyWebAppConfigurer
package com.lqx.springboot3.config
;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
/**
* 资源映射路径
*/
@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurationSupport {
@Override
protected void addResourceHandlers(ResourceHandlerRegistry registry) {
// 如果没有，所有的静态资源都获取不到 默认将静态资源当请求处理
registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
registry.addResourceHandler("/uploadImages/**").addResourceLocations("file:E:/temp/");
super.addResourceHandlers(registry);
}
}
在application.yml中解决图片大小问题
server:
servlet:
context-path: /
port: 80
spring:
jpa:
hibernate:
ddl-auto: update
show-sql: true
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ssm?useUnicode=true&characterEncoding=utf8
username: root
password: 123
druid:
initial-size: 5
min-idle: 5
max-active: 20
max-wait: 60000
time-between-eviction-runs-millis: 60000
min-evictable-idle-time-millis: 30000
validation-query: SELECT 1 FROM DUAL
test-while-idle: true
test-on-borrow: true
test-on-return: false
pool-prepared-statements: true
max-pool-prepared-statement-per-connection-size: 20
filter:
stat:
merge-sql: true
slow-sql-millis: 5000
web-stat-filter:
enabled: true
url-pattern: /*
exclusions: "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"
session-stat-enable: true
session-stat-max-count: 100
stat-view-servlet:
enabled: true
url-pattern: /druid/*
reset-enable: true
login-username: admin
login-password: admin
allow: 127.0.0.1
thymeleaf:
cache: false
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servlet:
multipart:
max-file-size: 20MB
max-request-size: 60MB
package com.lqx.springboot3.utils;
import javax.servlet.http.HttpServletRequest;
import java.util.Map;
/**
* 分页工具类
*/
public class PageBean {
private int page = 1;// 页码
private int rows = 3;// 页大小
private int total = 0;// 总记录数
private boolean pagination = true;// 是否分页
// 保存上次查询的参数
private Map paramMap;
// 保存上次查询的url
private String url;
public void setRequest(HttpServletRequest request) {
String page = request.getParameter("page");
String rows = request.getParameter("offset");
String pagination = request.getParameter("pagination");
this.setPage(page);
this.setRows(rows);
this.setPagination(pagination);
this.setUrl(request.getRequestURL().toString());
this.setParamMap(request.getParameterMap());
}
public PageBean() {
super();
}
public Map getParamMap() {
return paramMap;
}
public void setParamMap(Map paramMap) {
this.paramMap = paramMap;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public void setPage(String page) {
if(StringUtils.isNotBlank(page)) {
this.page = Integer.parseInt(page);
}
}
public int getRows() {
return rows;
}
public void setRows(String rows) {
if(StringUtils.isNotBlank(rows)) {
this.rows = Integer.parseInt(rows);
}
}
public int getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
public void setTotal(String total) {
if(StringUtils.isNotBlank(total)) {
this.total = Integer.parseInt(total);
}
}
public boolean isPagination() {
return pagination;
}
public void setPagination(boolean pagination) {
this.pagination = pagination;
}
public void setPagination(String pagination) {
if(StringUtils.isNotBlank(pagination) && "false".equals(pagination)) {
this.pagination = Boolean.parseBoolean(pagination);
}
}
/**
* 最大页
* @return
*/
public int getMaxPage() {
int max = this.total/this.rows;
if(this.total % this.rows !=0) {
max ++ ;
}
return max;
}
/**
* 下一页
* @return
*/
public int getNextPage() {
int nextPage = this.page + 1;
if(nextPage > this.getMaxPage()) {
nextPage = this.getMaxPage();
}
return nextPage;
}
/**
* 上一页
* @return
*/
public int getPreviousPage() {
int previousPage = this.page -1;
if(previousPage < 1) {
previousPage = 1;
}
return previousPage;
}
/**
* 获得起始记录的下标
*
* @return
*/
public int getStartIndex() {
return (this.page - 1) * this.rows;
}
@Override
public String toString() {
return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
}
}
package com.lqx.springboot3.utils;
import java.util.Map;
import java.util.Set;
/**
* @author 小李飞刀
* @site www.javaxl.com
* @company
* @create 2019-02-20 21:38
*
* 基于bootstrap3生成分页代码
*/
public class PageUtil {
public static String createPageCode(PageBean pageBean) {
StringBuffer sb = new StringBuffer();
/*
* 拼接向后台提交数据的form表单
* 注意：拼接的form表单中的page参数是变化的，所以不需要保留上一次请求的值
*/
sb.append("");
if(pageBean.getTotal()==0){
return "未查询到数据";
}else{
sb.append("首页 ");
if(pageBean.getPage()>1){
sb.append("上一页 ");
}else{
sb.append("上一页 ");
}
for(int i=pageBean.getPage()-1;i<=pageBean.getPage()+1;i++){
if(i<1||i>pageBean.getMaxPage()){
continue;
}
if(i==pageBean.getPage()){
sb.append(""+i+" ");
}else{
sb.append(""+i+" ");
}
}
if(pageBean.getPage()下一页");
}else{
sb.append("下一页 ");
}
sb.append("尾页 ");
}
/*
* 给分页条添加与后台交互的js代码
*/
sb.append("");
return sb.toString();
}
}
package com.lqx.springboot3.utils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;
public class StringUtils {
// 私有的构造方法，保护此类不能在外部实例化
private StringUtils() {
}
/**
* 如果字符串等于null或去空格后等于""，则返回true，否则返回false
*
* @param s
* @return
*/
public static boolean isBlank(String s) {
boolean b = false;
if (null == s || s.trim().equals("")) {
b = true;
}
return b;
}
/**
* 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
*
* @param s
* @return
*/
public static boolean isNotBlank(String s) {
return !isBlank(s);
}
/**
* set集合转string
* @param hasPerms
* @return
*/
public static String SetToString(Set hasPerms){
return Arrays.toString(hasPerms.toArray()).replaceAll(" ", "").replace("[", "").replace("]", "");
}
/**
* 转换成模糊查询所需参数
* @param before
* @return
*/
public static String toLikeStr(String before){
return isBlank(before) ? null : "%"+before+"%";
}
/**
* 将图片的服务器访问地址转换为真实存放地址
* @param imgpath 图片访问地址（http://localhost:8080/uploadImage/2019/01/26/20190126000000.jpg）
* @param serverDir uploadImage
* @param realDir E:/temp/
* @return
*/
public static String serverPath2realPath(String imgpath, String serverDir, String realDir) {
imgpath = imgpath.substring(imgpath.indexOf(serverDir));
return imgpath.replace(serverDir,realDir);
}
/**
* 过滤掉集合里的空格
* @param list
* @return
*/
public static List filterWhite(List list){
List resultList=new ArrayList();
for(String l:list){
if(isNotBlank(l)){
resultList.add(l);
}
}
return resultList;
}
/**
* 从html中提取纯文本
* @param strHtml
* @return
*/
public static String html2Text(String strHtml) {
String txtcontent = strHtml.replaceAll("]+>", ""); //剔出的标签
txtcontent = txtcontent.replaceAll("\\s*|\t|\r|\n", "");//去除字符串中的空格,回车,换行符,制表符
return txtcontent;
}
public static void main(String[] args) {
}
}
package com.lqx.springboot3.entity;
import lombok.ToString;
import javax.persistence.*;
/**
* @author 小李飞刀
* @site www.javaxl.com
* @company
* @create 2019-02-20 21:58
*/
@Entity
@Table(name = "t_springboot_teacher")
@ToString
public class Teacher {
@Id
@GeneratedValue
private Integer tid;
@Column(length = 16)
private String tname;
@Column(length = 4)
private String sex;
@Column(length = 100)
private String description;
@Column(length = 200)
private String imagePath;
public Integer getTid() {
return tid;
}
public void setTid(Integer tid) {
this.tid = tid;
}
public String getTname() {
return tname;
}
public void setTname(String tname) {
this.tname = tname;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getImagePath() {
return imagePath;
}
public void setImagePath(String imagePath) {
this.imagePath = imagePath;
}
}
package com.lqx.springboot3.dao;
import com.lqx.springboot3.entity.Teacher;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
/**
* @author 小李飞刀
* @site www.javaxl.com
* @company
* @create 2019-02-18 11:36
*
* 只要继承JpaRepository，通常所用的增删查改方法都有
* 第一个参数：操作的实体类
* 第二个参数：实体类对应数据表的主键
*
* 要使用高级查询必须继承
* org.springframework.data.jpa.repository.JpaSpecificationExecutor接口
*/
public interface TeacherDao extends JpaRepository, JpaSpecificationExecutor {
}
package com.lqx.springboot3.Service;
import com.lqx.springboot3.entity.Teacher;
import com.lqx.springboot3.utils.PageBean;
import com.lqx.springboot3.utils.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
/**
* @author 我
* @site www.xxx.com
* @company xxx公司
* @create 2019-11-13 21:57
*/
public interface TeacherService {
public Teacher save(Teacher teacher);
public void deleteById(Integer id);
public Teacher findById(Integer id);
public Page listPager(Teacher teacher, PageBean pageBean);
}
package com.lqx.springboot3.Service.impl;
import com.lqx.springboot3.dao.TeacherDao;
import com.lqx.springboot3.Service.TeacherService;
import com.lqx.springboot3.entity.Teacher;
import com.lqx.springboot3.utils.PageBean;
import com.lqx.springboot3.utils.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
@Service
public class TeacherServiceImpl implements TeacherService {
@Autowired
private TeacherDao teacherDao;
@Override
public Teacher save(Teacher teacher) {
return teacherDao.save(teacher);
}
@Override
public void deleteById(Integer id) {
teacherDao.deleteById(id);
}
@Override
public Teacher findById(Integer id) {
return teacherDao.findById(id).get();
}
@Override
public Page listPager(Teacher teacher, PageBean pageBean) {
// jpa的Pageable分页是从0页码开始
Pageable pageable = PageRequest.of(pageBean.getPage()-1, pageBean.getRows());
return teacherDao.findAll(new Specification() {
@Override
public Predicate toPredicate(Root root, CriteriaQuery criteriaQuery, CriteriaBuilder criteriaBuilder) {
Predicate predicate = criteriaBuilder.conjunction();
if(teacher != null){
if(StringUtils.isNotBlank(teacher.getTname())){
//如果多表联查这里的tname一定是属性的名字而不是外键的名字
predicate.getExpressions().add(criteriaBuilder.like(root.get("tname"),"%"+teacher.getTname()+"%"));
}
}
return predicate;
}
},pageable);
}
}
package com.lqx.springboot3.Controller;
import com.lqx.springboot3.Service.TeacherService;
import com.lqx.springboot3.entity.Teacher;
import com.lqx.springboot3.utils.PageBean;
import com.lqx.springboot3.utils.PageUtil;
import com.lqx.springboot3.utils.StringUtils;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
/**
* @author 小李飞刀
* @site www.javaxl.com
* @company
* @create 2019-02-20 22:15
*/
@Controller
@RequestMapping("/teacher")
public class TeacherController {
@Autowired
private TeacherService teacherService;
@RequestMapping("/listPager")
public ModelAndView list(Teacher teacher, HttpServletRequest request){
PageBean pageBean = new PageBean();
pageBean.setRequest(request);
ModelAndView modelAndView = new ModelAndView();
Page teachers = teacherService.listPager(teacher, pageBean);
modelAndView.addObject("teachers",teachers.getContent());
pageBean.setTotal(teachers.getTotalElements()+"");
modelAndView.addObject("pageCode", PageUtil.createPageCode(pageBean)/*.replaceAll("<","<").replaceAll(">:",">")*/);
modelAndView.setViewName("list");
return modelAndView;
}
@RequestMapping("/toEdit")
public ModelAndView toEdit(Teacher teacher){
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("edit");
modelAndView.addObject("sexArr",new String[]{"男","女"});
if(!(teacher.getTid() == null || "".equals(teacher.getTid()))) {
Teacher t = teacherService.findById(teacher.getTid());
modelAndView.addObject("teacher", t);
}
return modelAndView;
}
@RequestMapping("/add")
public String add(Teacher teacher, MultipartFile image){
try {
String diskPath = "E://temp/"+image.getOriginalFilename();
String serverPath = "/uploadImages/"+image.getOriginalFilename();
if(StringUtils.isNotBlank(image.getOriginalFilename())){
FileUtils.copyInputStreamToFile(image.getInputStream(),new File(diskPath));
teacher.setImagePath(serverPath);
}
teacherService.save(teacher);
} catch (IOException e) {
e.printStackTrace();
}
return "redirect:/teacher/listPager";
}
@RequestMapping("/edit")
public String edit(Teacher teacher, MultipartFile image){
String diskPath = "E://temp/"+image.getOriginalFilename();
String serverPath = "/uploadImages/"+image.getOriginalFilename();
if(StringUtils.isNotBlank(image.getOriginalFilename())){
try {
FileUtils.copyInputStreamToFile(image.getInputStream(),new File(diskPath));
teacher.setImagePath(serverPath);
} catch (IOException e) {
e.printStackTrace();
}
}
teacherService.save(teacher);
return "redirect:/teacher/listPager";
}
@RequestMapping("/del/{bid}")
public String del(@PathVariable(value = "bid") Integer bid){
teacherService.deleteById(bid);
return "redirect:/teacher/listPager";
}
}
html
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