spring boot 第二課-完成單表操作及分頁查詢
阿新 • • 發佈：2019-01-03
@PathVariable ：http 請求路徑中所帶引數的設定的註解
@RequestMapping(value="/getuser/{id}")
public User getUser(@PathVariable Long id){
User u=new User();
u.setId(1);
u.setName("hering");
u.setPassword("123456");
map.put(1l, u);
return u;
}
3.介面定義（如果加上事務就直接加在介面上面，springboot 會根據註解自動生成一個代理的例項）
4.執行的類
5.bean 的類：（這裡通過註釋，不需要再手動建立資料庫，實現註解，在程式啟動的時候，自動建立表，建立表的模式有可以參考
第二部分：單表操作及查詢分頁
1.pom.xml 配置如下：
2.資料庫配置檔案，讓在resource 目錄下面<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.it.guo</groupId> <artifactId>sboot</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>sboot Maven Webapp</name> <url>http://maven.apache.org</url> <!-- spring-boot-starter-parent 包含了以下資訊 - --> <!-- 1、使用java6編譯級別 2、使用utf-8編碼 3、實現了通用的測試框架 (JUnit, Hamcrest, Mockito). 4、智慧資源過濾 5、智慧的外掛配置(exec plugin, surefire, Git commit ID, shade). --> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.3.5.RELEASE</version> <relativePath /> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <!-- spring boot 核心 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!-- 引入web 模組 需要新增 --> <!-- http://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>1.3.5.RELEASE</version> </dependency> <!-- 開發工具 --> <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> <version>5.1.31</version> </dependency> </dependencies> <build> <finalName>sboot</finalName> <plugins> <plugin> <!-- 自動重動 該工程在spring boot開發過程中非常有用，當工程檔案發生變化的時候工程能夠自動重啟生效變化的內容 --> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <!-- <configuration> <fork>true</fork> </configuration> --> </plugin> </plugins> </build> <repositories> <repository> <id>spring-releases</id> <name>Spring Releases</name> <url>https://repo.spring.io/libs-release</url> </repository> <repository> <id>org.jboss.repository.releases</id> <name>JBoss Maven Release Repository</name> <url>https://repository.jboss.org/nexus/content/repositories/releases</url> </repository> </repositories> <pluginRepositories> <pluginRepository> <id>spring-releases</id> <name>Spring Releases</name> <url>https://repo.spring.io/libs-release</url> </pluginRepository> </pluginRepositories> </project>
spring.datasource.url=jdbc:mysql://localhost:3306/simple_service spring.datasource.username=banana spring.datasource.password=123456 spring.datasource.driver-class-name=com.mysql.jdbc.Driver #spring.jpa.properties.hibernate.hbm2ddl.auto=create-drop spring.jpa.hibernate.ddl-auto=update # Naming strategy spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy # stripped before adding them to the entity manager) spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect hibernate.show_sql=true hibernate.format_sql=true
3.介面定義（如果加上事務就直接加在介面上面，springboot 會根據註解自動生成一個代理的例項）
package com.it.core.repository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.transaction.annotation.Transactional;
import com.it.core.bean.UserInfo;
@Transactional
public interface UserRepository extends PagingAndSortingRepository<UserInfo, Long>, JpaSpecificationExecutor<UserInfo> {
// 原生的mysql 也可以用jpal 面向物件的程式設計
@Query(value = "select u.* from userinfo u where u.name = ?1", nativeQuery = true)
UserInfo findByname(String name);
// 修改
@Modifying
@Query(value = "update UserInfo set name=?1 where name=?2")
void updateUser(String newName, String oldName);
// 刪除
@Modifying
@Query(value = "delete from UserInfo where id=?1")
void delete(Integer id);
}
4.執行的類
package com.it.core.web;
import java.util.Iterator;
import javax.persistence.EntityManager;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.orm.jpa.EntityScan;
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.data.jpa.repository.config.EnableJpaRepositories;
import com.it.core.bean.UserInfo;
import com.it.core.repository.UserRepository;
@EnableAutoConfiguration
@EntityScan("com.it.core.bean")
@EnableJpaRepositories("com.it.core.repository")
public class Appliation implements CommandLineRunner {
@Autowired
UserRepository userRepository;
// private EntityManager entity = null;
// new LocalContainerEntityManagerFactoryBean();
/**
* start tomcat
*
* @param args
*/
public static void main(String[] args) {
SpringApplication.run(Appliation.class);
}
@Override
public void run(String... args) throws Exception {
// add
userRepository.save(new UserInfo("test123"));
// 查詢
UserInfo u = userRepository.findByname("howell0");
if (u != null) {
System.err.println(u.getName() + "---------");
// 修改
userRepository.updateUser("howell_zhang", "howell0");
// 再次chaxun
UserInfo u1 = userRepository.findByname("howell_zhang");
System.err.println(u1.getName() + "---------");
}
// 刪除
userRepository.delete(9);
// 分頁
Iterator<UserInfo> i = findAllwitPage().iterator();
while (i.hasNext()) {
UserInfo o = (UserInfo) i.next();
System.err.println(o.getName() + "----");
}
}
public Page<UserInfo> findAllwitPage() {
Pageable pageable = new PageRequest(1, 20);
// 通常使用Specification 的匿名內部類，
Specification<UserInfo> specification = new Specification<UserInfo>() {
/*
* @param root:代表的查詢的實體類
*
* @param query：可以從中得到Root物件，即告知JPA Criteria查詢要查詢哪一個實體類，
* 還可以來新增查詢條件，還可以結合EntityManager物件得到最終查詢的TypedQuery 物件
*
* @Param
* cb:criteriabuildre物件，用於建立Criteria相關的物件工程，當然可以從中獲取到predicate型別
*
* @return:代表一個查詢條件
*/
@Override
public Predicate toPredicate(Root<UserInfo> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
// Predicate p1 = cb.like(root.get("id").as(String.class), "%" +
// "1" + "%");
Predicate p2 = cb.like(root.get("name").as(String.class), "%" + "howell" + "%");
// Predicate p3 = cb.like(root.get("email").as(String.class),
// "%s%");
// 構建組合的Predicate示例：
Predicate p = cb.and(p2);
return p;
}
};
return userRepository.findAll(specification, pageable);
}
}
5.bean 的類：（這裡通過註釋，不需要再手動建立資料庫，實現註解，在程式啟動的時候，自動建立表，建立表的模式有可以參考
application.properties 中的：#spring.jpa.properties.hibernate.hbm2ddl.auto=create-drop
spring.jpa.hibernate.ddl-auto=update 屬性）
package com.it.core.bean;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name="userinfo")
public class UserInfo implements Serializable{
private static final long serialVersionUID = 1L;
private int id;
private String name;
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id",unique=true,nullable=false)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Column(name="name",unique=true,nullable=false)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public UserInfo(String name) {
this.name = name;
}
public UserInfo() {
}
}