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>

pom.xml

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

application.properties

<!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>

index.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);
}
}

App.java

完整的项目结构如下图所示:

玩转spring boot——结合JPA入门

运行效果如下图,我就不做说明了:

玩转spring boot——结合JPA入门

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>

index.html

运行效果:

玩转spring boot——结合JPA入门

like查询:

玩转spring boot——结合JPA入门

日期区间查询:

玩转spring boot——结合JPA入门

小于查询:

玩转spring boot——结合JPA入门

 总结


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

玩转spring boot——结合JPA入门

代码:https://github.com/carter659/spring-boot-05.git

玩转spring boot——结合JPA入门

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:)

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