SpringBoot SpringDataJPA 动态查询、多条件查询

Spring-data - JPA用的还是比较多的，之前在公司也一直在用，因为方便。下面我们来整理一下如何配置。

pom.xml

    4.0.0

    springdatajpademo
    springdatajpademo
    1.0-SNAPSHOT

    
        
        UTF-8
        zh_CN
        1.7
        1.7
        
        4.1.9.RELEASE
        1.9.2.RELEASE
        
        5.1.1.Final
        5.1.32
        4.0.7
        1.2.7
        9.1.0.v20131115
        2.7.7
        data-manager-server
        com.goldmsg.res.Bootstrap
    

    
        
        
            org.springframework
            spring-context
            ${org.springframework.version}
        
        
            org.springframework
            spring-test
            ${org.springframework.version}
        
        
        
            org.springframework.data
            spring-data-jpa
            ${org.springframework.data.version}
        
        
            org.hibernate
            hibernate-core
            ${org.hibernate.version}
        
        
            org.hibernate
            hibernate-entitymanager
            ${org.hibernate.version}
        
        
        
            mysql
            mysql-connector-java
            ${mysql.connector.version}
        
        
        
            com.alibaba
            druid
            1.0.15
        
    
    

userInfo.java

import javax.persistence.*;

/**
 * Created with IntelliJ IDEA.
 * User: lu
 * Date: 17-3-30
 * Time: 下午5:57
 * To change this template use File | Settings | File Templates.
 */
@Entity
@Table(name="obj_user")
@NamedQuery(name="UserInfo.findAll", query="SELECT o FROM UserInfo o")
public class UserInfo {
    private int userId;
    private String name;
    private int age;
    private long high;

    @javax.persistence.Id
    @Column(name="user_id")
    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public long getHigh() {
        return high;
    }

    public void setHigh(long high) {
        this.high = high;
    }
}

UserInfoDao.java

public interface UserInfoDao extends PagingAndSortingRepository, JpaSpecificationExecutor {

}

UserInfoSpecDao.java

import com.springdatajpademo.pojo.UserInfo;
import com.springdatajpademo.pojo.UserInfo_;
import org.springframework.data.jpa.domain.Specification;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

/**
 * Created with IntelliJ IDEA.
 * User: lu
 * Date: 17-3-30
 * Time: 下午8:05
 * To change this template use File | Settings | File Templates.
 */
public class UserInfoDaoSpec {
    public static Specification getSpec(final String name,final int age,final int high) {
        return new Specification() {

            @Override
            public Predicate toPredicate(Root root, CriteriaQuery query, CriteriaBuilder cb) {
                Predicate p1 = null;
                if(name!=null) {
                    Predicate p2 = cb.equal(root.get(UserInfo_.name),name);
                    if(p1 != null) {
                        p1 = cb.and(p1,p2);
                    } else {
                        p1 = p2;
                    }
                }

                if(age!=0) {
                    Predicate p2 = cb.equal(root.get(UserInfo_.age), age);
                    if(p1 != null) {
                        p1 = cb.and(p1,p2);
                    } else {
                        p1 = p2;
                    }
                }

                if(high!=0) {
                    Predicate p2 = cb.equal(root.get(UserInfo_.high), high);
                    if(p1 != null) {
                        p1 = cb.and(p1,p2);
                    } else {
                        p1 = p2;
                    }
                }

                return p1;
            }
        };
    }
}

UserInfoExtendDao.java

import com.springdatajpademo.pojo.UserInfo;
import com.springdatajpademo.pojo.UserInfo_;
import com.springdatajpademo.pojo.UserStat;
import org.springframework.stereotype.Repository;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Tuple;
import javax.persistence.criteria.*;
import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * User: lu
 * Date: 17-3-31
 * Time: 上午10:32
 * To change this template use File | Settings | File Templates.
 */
@Repository
public class UserInfoExtendDao {

    @PersistenceContext(unitName = "springJpa")
    EntityManager em;

    public List getUserInfo(String name,int age,int high) {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery query = cb.createQuery(UserInfo.class);

        //from
        Root root = query.from(UserInfo.class);

        //where
        Predicate p1 = null;
        if(name!=null) {
            Predicate p2 = cb.equal(root.get(UserInfo_.name),name);
            if(p1 != null) {
                p1 = cb.and(p1,p2);
            } else {
                p1 = p2;
            }
        }

        if(age!=0) {
            Predicate p2 = cb.equal(root.get(UserInfo_.age), age);
            if(p1 != null) {
                p1 = cb.and(p1,p2);
            } else {
                p1 = p2;
            }
        }

        if(high!=0) {
            Predicate p2 = cb.equal(root.get(UserInfo_.high), high);
            if(p1 != null) {
                p1 = cb.and(p1,p2);
            } else {
                p1 = p2;
            }
        }
        query.where(p1);

        List userInfos = em.createQuery(query).getResultList();
        return userInfos;
    }



    public UserStat getUserStat(String name) {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery query = cb.createTupleQuery();

        //from
        Root root = query.from(UserInfo.class);

        //select
        Selection countUser;
        Selection sumHigh;

        countUser = cb.count(root.get(UserInfo_.userId));
        sumHigh = cb.sum(root.get(UserInfo_.high));

        CompoundSelection selection = cb.tuple(countUser, sumHigh);

        //where
        Predicate predicate = cb.equal(root.get(UserInfo_.name), name);

        //query
        CriteriaQuery criteriaQuery = query.select(selection).where(predicate);

        Tuple tuple = em.createQuery(criteriaQuery).getSingleResult();
        UserStat userStat = new UserStat();
        userStat.setCountUser(tuple.get(countUser));
        userStat.setSumHigh(tuple.get(sumHigh));

        return userStat;
    }
}

Application.java

import com.springdatajpademo.pojo.UserInfo;
import com.springdatajpademo.pojo.UserStat;
import com.springdatajpademo.repository.UserInfoDao;
import com.springdatajpademo.repository.UserInfoDaoSpec;
import com.springdatajpademo.repository.UserInfoExtendDao;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;


public class Application {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Application  application = new Application ();
        application .testJpa1(applicationContext);
        application .testJpa2(applicationContext);

    }

    public void testJpa1(ClassPathXmlApplicationContext applicationContext) {
        UserInfoExtendDao userInfoExtendDao = (UserInfoExtendDao)applicationContext.getBean("userInfoExtendDao");

        List userInfos = userInfoExtendDao.getUserInfo("张三",16,165);
        printUserInfo(userInfos);

        UserStat userStat = userInfoExtendDao.getUserStat("张三");
        System.out.println(userStat.getCountUser());
        System.out.println(userStat.getSumHigh());
    }

    public void testJpa2(ClassPathXmlApplicationContext applicationContext) {
        UserInfoDao userInfoDao = (UserInfoDao)applicationContext.getBean("userInfoDao");
        {
            //三个条件:"张三",16,165
            System.out.println("\n三个条件:张三,16,165");
            List userInfos = userInfoDao.findAll(UserInfoDaoSpec.getSpec("张三",16,165));
            printUserInfo(userInfos);
        }

        {
            //两个条件:"张三",16,这里假设赋值0为未赋值
            System.out.println("\n两个条件:张三,16");
            List userInfos = userInfoDao.findAll(UserInfoDaoSpec.getSpec("张三",16,0));
            printUserInfo(userInfos);
        }

        {
            //两个条件:"张三",16,这里假设赋值0为未赋值
            System.out.println("\n一个条件:张三");
            List userInfos = userInfoDao.findAll(UserInfoDaoSpec.getSpec("张三",0,0));
            printUserInfo(userInfos);
        }

    }

    private void printUserInfo(List userInfos) {
        if(userInfos!=null) {
            for(UserInfo userInfo : userInfos) {
                System.out.println("userId:"+userInfo.getUserId()+" name:"+userInfo.getName());
            }
        }
    }


}

以上配置来自网络，有问题可以在下面评论，技术问题可以私聊我。

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