springboot之jpa的支持

1、springboot之jpa支持

2、Springboot+bootstrap界面版之增删改查及图片上传

springboot之jpa支持

导入相关pom依赖

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

application.yml文件配置

server:
  port:
  servlet:
    context-path: /

spring:
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
  datasource:
    #.JDBC
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/xm1?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password:
    druid:
      initial-size:
      min-idle:
      max-active:
      max-wait:
      time-between-eviction-runs-millis:
      min-evictable-idle-time-millis:
      validation-query: SELECT  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:
      filter:
        stat:
          merge-sql: true
          slow-sql-millis:
      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
        #deny: 192.168.1.100

自动建表相关代码

package com.jt.springboot03.entity;

import lombok.Data;

import javax.persistence.*;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:04
 */
@Data
@Table(name="t_springboot_book_2019")
@Entity
public class Book {
    @Id
    @GeneratedValue
    private Integer bid;
    @Column(length = )
    private String bname;
    @Column
    private Float price;
}

controller层

package com.jt.springboot03.controller;

import com.jt.springboot03.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:15
 */
@RestController
public class BookController {
    @Autowired
    private JpaRepository jpaDao;

    @RequestMapping("/add")
    public String add(Book book) {
        jpaDao.save(book);
        return "success";
    }

    @RequestMapping("/edit")
    public String edit(Book book) {
        jpaDao.save(book);
        return "success";
    }

    @RequestMapping("/del")
    public String del(Book book) {
        jpaDao.delete(book);
        return "success";
    }

    @RequestMapping("/getOne")
    public Book getOne(Integer bid) {
//        会出现懒加载问题：org.hibernate.LazyInitializationException: could not initialize proxy - no Session
//        return jpaDao.getOne(bid);
        return (Book)jpaDao.findById(bid).get();
    }

    @RequestMapping("/getAll")
    public List<Book> getAll() {
        return jpaDao.findAll();
    }
}

BookRepository

package com.jt.springboot03.repository;

import com.jt.springboot03.entity.Book;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:13
 */
@Repository
public interface BookRepository extends JpaRepository<Book,Integer> {

}

Springboot+bootstrap界面版之增删改查及图片上传

pom依赖

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.</version>
</dependency>

实体类

package com.jt.springboot03.entity;

import lombok.ToString;

import javax.persistence.*;

@Entity
@Table(name = "t_springboot_teacher")
@ToString
public class Teacher {
    @Id
    @GeneratedValue
    private Integer tid;
    @Column(length = )
    private String tname;
    @Column(length = )
    private String sex;
    @Column(length = )
    private String description;
    @Column(length = )
    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;
    }
}

application.yml文件配置

server:
  port:
  servlet:
    context-path: /

spring:
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
  datasource:
    #.JDBC
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/xm1?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password:
    druid:
      initial-size:
      min-idle:
      max-active:
      max-wait:
      time-between-eviction-runs-millis:
      min-evictable-idle-time-millis:
      validation-query: SELECT  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:
      filter:
        stat:
          merge-sql: true
          slow-sql-millis:
      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
        #deny: 192.168.1.100
  thymeleaf:
    cache: false

  servlet:
    multipart:
      max-file-size: 20MB
      max-request-size: 60MB

上传文件映射配置类MyWebAppConfigurer.java

package com.jt.springboot03.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:40
 */
@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurationSupport {
    @Override
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
        registry.addResourceHandler("/uploadImages/**").addResourceLocations("file:E:/temp/");
        super.addResourceHandlers(registry);
    }
}

utils包

package com.jt.springboot03.utils;

import javax.servlet.http.HttpServletRequest;
import java.util.Map;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:43
 */
/**
 * 分页工具类
 */
public class PageBean {

    private int page = ;// 页码

    private int rows = ;// 页大小

    private int total = ;// 总记录数

    private boolean pagination = true;// 是否分页

    //    保存上次查询的参数
    private Map<String, String[]> 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<String, String[]> getParamMap() {
        return paramMap;
    }

    public void setParamMap(Map<String, String[]> 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 !=) {
            max ++ ;
        }
        return max;
    }

    /**
     * 下一页
     * @return
     */
    public int getNextPage() {
        int nextPage = this.page + ;
        if(nextPage > this.getMaxPage()) {
            nextPage = this.getMaxPage();
        }
        return nextPage;
    }

    /**
     * 上一页
     * @return
     */
    public int getPreviousPage() {
        int previousPage = this.page -;
        if(previousPage < ) {
            previousPage = ;
        }
        return previousPage;
    }

    /**
     * 获得起始记录的下标
     *
     * @return
     */
    public int getStartIndex() {
        return (this.page - ) * this.rows;
    }

    @Override
    public String toString() {
        return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
    }
}

package com.jt.springboot03.utils;

import java.util.Map;
import java.util.Set;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:45
 */
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("<form id='pageBeanForm' action='"+pageBean.getUrl()+"' method='post'>");
        sb.append("<input type='hidden' name='page'>");
        Map<String, String[]> parameterMap = pageBean.getParamMap();
        if(parameterMap != null && parameterMap.size() > ) {
            Set<Map.Entry<String, String[]>> entrySet = parameterMap.entrySet();
            for (Map.Entry<String, String[]> entry : entrySet) {
                if(!"page".equals(entry.getKey())) {
                    String[] values = entry.getValue();
                    for (String val : values) {
                        sb.append("<input type='hidden' name='"+entry.getKey()+"' value='"+val+"'>");
                    }
                }
            }
        }
        sb.append("</form>");

        if(pageBean.getTotal()==){
            return "未查询到数据";
        }else{
            sb.append("<li><a href='javascript:gotoPage(1)'>首页</a></li>");
            if(pageBean.getPage()>){
                sb.append("<li><a href='javascript:gotoPage("+pageBean.getPreviousPage()+")'>上一页</a></li>");
            }else{
                sb.append("<li class='disabled'><a href='javascript:gotoPage(1)'>上一页</a></li>");
            }
            for(int i=pageBean.getPage()-;i<=pageBean.getPage()+;i++){
                if(i<||i>pageBean.getMaxPage()){
                    continue;
                }
                if(i==pageBean.getPage()){
                    sb.append("<li class='active'><a href='#'>"+i+"</a></li>");
                }else{
                    sb.append("<li><a href='javascript:gotoPage("+i+")'>"+i+"</a></li>");
                }
            }
            if(pageBean.getPage()<pageBean.getMaxPage()){
                sb.append("<li><a href='javascript:gotoPage("+pageBean.getNextPage()+")'>下一页</a></li>");
            }else{
                sb.append("<li class='disabled'><a href='javascript:gotoPage("+pageBean.getMaxPage()+")'>下一页</a></li>");
            }
            sb.append("<li><a href='javascript:gotoPage("+pageBean.getMaxPage()+")'>尾页</a></li>");
        }

        /*
         * 给分页条添加与后台交互的js代码
         */
        sb.append("<script type='text/javascript'>");
        sb.append("        function gotoPage(page) {");
        sb.append("            document.getElementById('pageBeanForm').page.value = page;");
        sb.append("            document.getElementById('pageBeanForm').submit();");
        sb.append("        }");
        sb.append("        function skipPage() {");
        sb.append("            var page = document.getElementById('skipPage').value;");
        sb.append("            if(!page || isNaN(page) || parseInt(page)<1 || parseInt(page)>"+pageBean.getMaxPage()+"){");
        sb.append("                alert('请输入1~N的数字');");
        sb.append("                return;");
        sb.append("            }");
        sb.append("            gotoPage(page);");
        sb.append("        }");
        sb.append("</script>");
        return sb.toString();
    }
}

package com.jt.springboot03.utils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:41
 */
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<String> filterWhite(List<String> list){
        List<String> resultList=new ArrayList<String>();
        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<html>的标签
        txtcontent = txtcontent.replaceAll("<a>\\s*|\t|\r|\n</a>", "");//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) {
    }
}

service层

TeacherService

package com.jt.springboot03.service;

import com.jt.springboot03.entity.Teacher;
import com.jt.springboot03.utils.PageBean;
import org.springframework.data.domain.Page;

/**
 * @author jt
 * @site www.xiaomage.com
 * @company xxx公司
 * @create  2019-11-30 16:57
 */
public interface TeacherService {
    public Teacher save(Teacher teacher);
    public void deleteById(Integer id);
    public Teacher findById(Integer id);
    public Page<Teacher> listPager(Teacher teacher, PageBean pageBean);

}

TeacherServiceImpl

package com.jt.springboot03.service.impl;

import com.jt.springboot03.entity.Teacher;
import com.jt.springboot03.repository.TeacherDao;
import com.jt.springboot03.service.TeacherService;
import com.jt.springboot03.utils.PageBean;

import com.jt.springboot03.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<Teacher> listPager(Teacher teacher, PageBean pageBean) {
//        jpa的Pageable分页是从0页码开始
        Pageable pageable = PageRequest.of(pageBean.getPage()-, pageBean.getRows());
        return teacherDao.findAll(new Specification<Teacher>() {
            @Override
            public Predicate toPredicate(Root<Teacher> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                Predicate predicate = criteriaBuilder.conjunction();
                if(teacher != null){
                    if(StringUtils.isNotBlank(teacher.getTname())){
                        predicate.getExpressions().add(criteriaBuilder.like(root.get("tname"),"%"+teacher.getTname()+"%"));
                    }
                }
                return predicate;
            }
        },pageable);
    }
}

dao方法

package com.jt.springboot03.repository;

import com.jt.springboot03.entity.Teacher;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/**
 * 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<T>接口
 */
public interface TeacherDao extends JpaRepository<Teacher, Integer>, JpaSpecificationExecutor<Teacher> {
}

controller

TeacherController

package com.jt.springboot03.controller;

import com.jt.springboot03.entity.Teacher;
import com.jt.springboot03.service.TeacherService;
import com.jt.springboot03.utils.PageBean;
import com.jt.springboot03.utils.PageUtil;

import com.jt.springboot03.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;

@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<Teacher> teachers = teacherService.listPager(teacher, pageBean);
        modelAndView.addObject("teachers",teachers.getContent());
        pageBean.setTotal(teachers.getTotalElements()+"");
        modelAndView.addObject("pageCode", PageUtil.createPageCode(pageBean)/*.replaceAll("<","<").replaceAll("&gt:",">")*/);
        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";
    }
}

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