玩转spring boot——结合JPA入门
参考官方例子：https://spring.io/guides/gs/accessing-data-jpa/
接着上篇内容
一、小试牛刀
创建maven项目后，修改pom.xml文件
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.github.carter659</groupId> <artifactId>spring05</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.2.RELEASE</version> </parent> <name>spring05</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
多引入了JPA的依赖：
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency>
src/main/resources/application.properties和src/main/resources/templates/index.html保持上篇不变：
spring.datasource.initialize=false spring.datasource.url=jdbc:mysql://localhost:3306/demo spring.datasource.username=root spring.datasource.password= spring.datasource.driver-class-name=com.mysql.jdbc.Driver
<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>玩转spring boot——结合JPA</title> <script src="//cdn.bootcss.com/angular.js/1.5.6/angular.min.js"></script> <script type="text/javascript"> /*<![CDATA[*/ var app = angular.module('app', []); app.controller('MainController', function($rootScope, $scope, $http) { $scope.data = {}; $scope.rows = []; //添加 $scope.add = function() { $scope.data = { no : 'No.1234567890', quantity : 100, 'date' : '2016-12-30' }; } //编辑 $scope.edit = function(id) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (id == row.id) { $scope.data = row; return; } } } //移除 $scope.remove = function(id) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (id == row.id) { $scope.rows.splice(i, 1); return; } } } //保存 $scope.save = function() { $http({ url : '/save', method : 'POST', data : $scope.data }).success(function(r) { //保存成功后更新数据 $scope.get(r.id); }); } //删除 $scope.del = function(id) { $http({ url : '/delete?id=' + id, method : 'POST', }).success(function(r) { //删除成功后移除数据 $scope.remove(r.id); }); } //获取数据 $scope.get = function(id) { $http({ url : '/get?id=' + id, method : 'POST', }).success(function(data) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (data.id == row.id) { row.no = data.no; row.date = data.date; row.quantity = data.quantity; return; } } $scope.rows.push(data); }); } //初始化载入数据 $http({ url : '/findAll', method : 'POST' }).success(function(rows) { for ( var i in rows) { var row = rows[i]; $scope.rows.push(row); } }); }); /*]]>*/ </script> </head> <body ng-app="app" ng-controller="MainController"> <h1>玩转spring boot——结合JPA</h1> <h4> <a href="http://www.cnblogs.com/GoodHelper/">from 刘冬的博客</a> </h4> <input type="button" value="添加" ng-click="add()" /> <input type="button" value="保存" ng-click="save()" /> <br /> <br /> <h3>清单信息：</h3> <input id="id" type="hidden" ng-model="data.id" /> <table cellspacing="1" style="background-color: #a0c6e5"> <tr> <td>编号：</td> <td><input id="no" ng-model="data.no" /></td> <td>日期：</td> <td><input id="date" ng-model="data.date" /></td> <td>数量：</td> <td><input id="quantity" ng-model="data.quantity" /></td> </tr> </table> <br /> <h3>清单列表：</h3> <table cellspacing="1" style="background-color: #a0c6e5"> <tr style="text-align: center; COLOR: #0076C8; BACKGROUND-COLOR: #F4FAFF; font-weight: bold"> <td>操作</td> <td>编号</td> <td>日期</td> <td>数量</td> </tr> <tr ng-repeat="row in rows" bgcolor='#F4FAFF'> <td><input ng-click="edit(row.id)" value="编辑" type="button" /><input ng-click="del(row.id)" value="删除" type="button" /></td> <td>{{row.no}}</td> <td>{{row.date}}</td> <td>{{row.quantity}}</td> </tr> </table> <br /> <a href="http://www.cnblogs.com/GoodHelper/">点击访问原版博客</a> </body> </html>
修改上篇的“Order.java”类：
package com.github.carter659.spring05; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; import javax.persistence.Temporal; import javax.persistence.TemporalType; import org.hibernate.annotations.GenericGenerator; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ @Entity @Table(name = "t_order") public class Order { @Id @GeneratedValue(generator = "uuid") @GenericGenerator(name = "uuid", strategy = "uuid2") @Column(name = "order_id", length = 36) public String id; @Column(name = "order_no", length = 50) public String no; @Temporal(TemporalType.DATE) @Column(name = "order_date") public Date date; @Column(name = "quantity") public int quantity; /** * 省略 get set */ }
新建“OrderRepository.java”文件
package com.github.carter659.spring05; import org.springframework.data.jpa.repository.JpaRepository; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ public interface OrderRepository extends JpaRepository<Order, String> { }
这个类实现了JpaRepository<>接口，此接口附带常用的增删改查到方法。
修改上篇的控制器“MainController.java”文件
package com.github.carter659.spring05; import java.util.HashMap; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.ResponseBody; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ @Controller public class MainController { @Autowired private OrderRepository orderRepository; @GetMapping("/") public String index() { return "index"; } /** * 持久化 * * @param entity * @return */ @PostMapping("/save") public @ResponseBody Map<String, Object> save(@RequestBody Order entity) { Map<String, Object> result = new HashMap<>(); entity = orderRepository.save(entity); result.put("id", entity.id); return result; } /** * 获取对象 * * @param id * @return */ @PostMapping("/get") public @ResponseBody Object get(String id) { return orderRepository.findOne(id); } /** * 获取全部 * * @return */ @PostMapping("/findAll") public @ResponseBody Object findAll() { return orderRepository.findAll(); } /** * 删除 * * @param id * @return */ @PostMapping("/delete") public @ResponseBody Map<String, Object> delete(String id) { Map<String, Object> result = new HashMap<>(); orderRepository.delete(id); result.put("id", id); return result; } }
有人会问，在控制器中直接依赖注入了OrderRepository，并没有OrderRepository接口的实现类。在没有写实现类的情况下不报错吗？答案是并不报错，因为这些事儿都交给了JPA去做。那么为什么要用JPA，答案也只有2个字“方便”。我写这个系列博客的目的就是为了体现“方便”二字，使用最方便的技术来快速开发项目。
言归正传，App.java类保持不变：
package com.github.carter659.spring05; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ @SpringBootApplication public class App { public static void main(String[] args) { SpringApplication.run(App.class, args); } }
完整的项目结构如下图所示：
运行效果如下图，我就不做说明了：
二、高级查询
修改“OrderRepository.java”：
package com.github.carter659.spring05; import java.util.Date; import java.util.List; import org.springframework.data.jpa.repository.JpaRepository; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ public interface OrderRepository extends JpaRepository<Order, String> { /** * like查询 * * @param no * @return */ List<Order> findAllByNoLike(String no); /** * between查询 * * @param startDate * @param endDate * @return */ List<Order> findAllByDateBetween(Date startDate, Date endDate); /** * 小于查询 * * @param quantity * @return */ List<Order> findAllByQuantityLessThan(int quantity); }
package com.github.carter659.spring05; import java.text.SimpleDateFormat; import java.util.Date; import java.util.HashMap; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.propertyeditors.CustomDateEditor; import org.springframework.stereotype.Controller; import org.springframework.web.bind.WebDataBinder; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.InitBinder; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; /** * 博客出处：http://www.cnblogs.com/GoodHelper/ * * @author 刘冬 * */ @Controller public class MainController { @Autowired private OrderRepository orderRepository; /** * 处理日期类型 * * @param binder */ @InitBinder public void initBinder(WebDataBinder binder) { SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); dateFormat.setLenient(false); binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true)); } @GetMapping("/") public String index() { return "index"; } /** * 持久化 * * @param entity * @return */ @PostMapping("/save") public @ResponseBody Map<String, Object> save(@RequestBody Order entity) { Map<String, Object> result = new HashMap<>(); entity = orderRepository.save(entity); result.put("id", entity.id); return result; } /** * 获取对象 * * @param id * @return */ @PostMapping("/get") public @ResponseBody Object get(String id) { return orderRepository.findOne(id); } /** * 获取全部 * * @return */ @PostMapping("/findAll") public @ResponseBody Object findAll() { return orderRepository.findAll(); } /** * 删除 * * @param id * @return */ @PostMapping("/delete") public @ResponseBody Map<String, Object> delete(String id) { Map<String, Object> result = new HashMap<>(); orderRepository.delete(id); result.put("id", id); return result; } /** * like查询 * * @return */ @PostMapping("/findAllByNoLike") public @ResponseBody Object findAllByNoLike(@RequestParam String no) { return orderRepository.findAllByNoLike("%" + no + "%"); } /** * between查询 * * @return */ @PostMapping("/findAllByDateBetween") public @ResponseBody Object findAllByDateBetween(@RequestParam Date startDate, @RequestParam Date endDate) { return orderRepository.findAllByDateBetween(startDate, endDate); } /** * 小于查询 * * @return */ @PostMapping("/findAllByQuantityLessThan") public @ResponseBody Object findAllByQuantityLessThan(int quantity) { return orderRepository.findAllByQuantityLessThan(quantity); } }
<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>玩转spring boot——结合JPA</title> <script src="//cdn.bootcss.com/angular.js/1.5.6/angular.min.js"></script> <script type="text/javascript"> /*<![CDATA[*/ var app = angular.module('app', []); app .controller( 'MainController', function($rootScope, $scope, $http) { $scope.data = {}; $scope.rows = []; //添加 $scope.add = function() { $scope.data = { no : 'No.1234567890', quantity : 100, 'date' : '2016-12-30' }; } //编辑 $scope.edit = function(id) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (id == row.id) { $scope.data = row; return; } } } //移除 $scope.remove = function(id) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (id == row.id) { $scope.rows.splice(i, 1); return; } } } //保存 $scope.save = function() { $http({ url : '/save', method : 'POST', data : $scope.data }).success(function(r) { //保存成功后更新数据 $scope.get(r.id); }); } //删除 $scope.del = function(id) { $http({ url : '/delete?id=' + id, method : 'POST', }).success(function(r) { //删除成功后移除数据 $scope.remove(r.id); }); } //获取数据 $scope.get = function(id) { $http({ url : '/get?id=' + id, method : 'POST', }).success(function(data) { for ( var i in $scope.rows) { var row = $scope.rows[i]; if (data.id == row.id) { row.no = data.no; row.date = data.date; row.quantity = data.quantity; return; } } $scope.rows.push(data); }); } //初始化载入数据 $http({ url : '/findAll', method : 'POST' }).success(function(rows) { for ( var i in rows) { var row = rows[i]; $scope.rows.push(row); } }); $scope.findAllByNoLike = function() { $http( { url : '/findAllByNoLike', method : 'POST', headers : { 'Content-Type' : 'application/x-www-form-urlencoded' }, data : 'no=' + $scope.no }).success(function(rows) { $scope.rows = rows; }); }; $scope.findAllByDateBetween = function() { $http( { url : '/findAllByDateBetween', method : 'POST', headers : { 'Content-Type' : 'application/x-www-form-urlencoded' }, data : 'startDate=' + $scope.startDate + '&endDate=' + $scope.endDate }).success(function(rows) { $scope.rows = rows; }); }; $scope.findAllByQuantityLessThan = function() { $http( { url : '/findAllByQuantityLessThan', method : 'POST', headers : { 'Content-Type' : 'application/x-www-form-urlencoded' }, data : 'quantity=' + $scope.quantity }).success(function(rows) { $scope.rows = rows; }); }; }); /*]]>*/ </script> </head> <body ng-app="app" ng-controller="MainController"> <h1>玩转spring boot——结合JPA</h1> <h4> <a href="http://www.cnblogs.com/GoodHelper/">from 刘冬的博客</a> </h4> <input type="button" value="添加" ng-click="add()" /> <input type="button" value="保存" ng-click="save()" /> <br /> <br /> <h3>订单信息：</h3> <input type="hidden" ng-model="data.id" /> <table cellspacing="1" style="background-color: #a0c6e5"> <tr> <td>编号：</td> <td><input ng-model="data.no" /></td> <td>日期：</td> <td><input ng-model="data.date" /></td> <td>数量：</td> <td><input ng-model="data.quantity" /></td> </tr> </table> <br /> <h3>查询条件：</h3> <table cellspacing="1" style="background-color: #a0c6e5"> <tr> <td>编号：</td> <td><input ng-model="no" /></td> <td><input type="button" ng-click="findAllByNoLike()" value="like查询" /></td> </tr> <tr> <td>日期：</td> <td>从<input ng-model="startDate" />至<input ng-model="endDate" /></td> <td><input type="button" ng-click="findAllByDateBetween()" value="between查询" /></td> </tr> <tr> <td>数量：</td> <td><input ng-model="quantity" /></td> <td><input type="button" ng-click="findAllByQuantityLessThan()" value="小于查询" /></td> </tr> </table> <br /> <h3>订单列表：</h3> <table cellspacing="1" style="background-color: #a0c6e5"> <tr style="text-align: center; COLOR: #0076C8; BACKGROUND-COLOR: #F4FAFF; font-weight: bold"> <td>操作</td> <td>编号</td> <td>日期</td> <td>数量</td> </tr> <tr ng-repeat="row in rows" bgcolor='#F4FAFF'> <td><input ng-click="edit(row.id)" value="编辑" type="button" /><input ng-click="del(row.id)" value="删除" type="button" /></td> <td>{{row.no}}</td> <td>{{row.date}}</td> <td>{{row.quantity}}</td> </tr> </table> <br /> <a href="http://www.cnblogs.com/GoodHelper/">点击访问原版博客</a> </body> </html>
运行效果：
like查询：
日期区间查询：
小于查询：
JPA的知识点很多，只用一篇博客是介绍不完的，可能一本书都不一定讲完。等以后有机会希望我再写一个关于JPA的系列。也可以在本系列后面的实践篇中写一些与spring boot更多结合的内容。
也可以在文档中查询到JPA的属性表达式和JPQL表达式的API：
http://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repositories.query-methods.query-property-expressions
http://docs.oracle.com/javaee/6/tutorial/doc/gjivm.html
http://www.objectdb.com/api/java/jpa/queries
代码：https://github.com/carter659/spring-boot-05.git
如果你觉得我的博客对你有帮助，可以给我点儿打赏，左侧微信，右侧支付宝。
有可能就是你的一点打赏会让我的博客写的更好:)
玩转spring boot系列目录