Tips:
springboot版本：2.0.8.RELEASE
jdk：1.8
在设计数据库表的时候，不确定后期升级是否需要扩展字段，大多数人会添加扩展字段，PostgreSQL的jsonb类型为我们提供了极大的便利。
- 为了让JPA支持jsonb，需要自定义PostgreSQL9Dialect
import org.hibernate.dialect.PostgreSQL9Dialect;
import java.sql.Types;
public class CustomPostgreSqlDialect extends PostgreSQL9Dialect {
public CustomPostgreSqlDialect() {
super();
this.registerColumnType(Types.JAVA_OBJECT, "jsonb");
}
}
- 指定方言spring.jpa.database-platform: com.xxx.PostgreSqlDialect,如下
spring:
datasource:
driver-class-name: org.postgresql.Driver
url: jdbc:postgresql://localhost:5432/postgres
username: postgres
password: 123456
hikari:
connection-timeout: 20000
maximum-pool-size: 5
jpa:
hibernate:
ddl-auto: create
show-sql: true
database-platform: com.example.jsonb.config.CustomPostgreSqlDialect
properties:
hibernate.temp.use_jdbc_metadata_defaults: false
logging:
level:
org.hibernate.type.descriptor.sql.BasicBinder: trace
- 自定义jsonb数据类型
import com.fasterxml.jackson.databind.ObjectMapper;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.type.SerializationException;
import org.hibernate.usertype.UserType;
import org.postgresql.util.PGobject;
import org.springframework.util.ObjectUtils;
import java.io.IOException;
import java.io.Serializable;
import java.sql.*;
import java.util.HashMap;
import java.util.Map;
public class JsonbType implements UserType {
private final ObjectMapper mapper = new ObjectMapper();
@Override
public int[] sqlTypes() {
return new int[]{Types.JAVA_OBJECT};
}
@Override
public Class returnedClass() {
return Map.class;
}
@Override
public boolean equals(Object x, Object y) throws HibernateException {
return ObjectUtils.nullSafeEquals(x, y);
}
@Override
public int hashCode(Object x) throws HibernateException {
return x == null ? 0 : x.hashCode();
}
@Override
public Object nullSafeGet(ResultSet rs, String[] names, SharedSessionContractImplementor sharedSessionContractImplementor, Object owner) throws HibernateException, SQLException {
Object obj = rs.getObject(names[0]);
if (obj == null) {
return null;
}
PGobject o = (PGobject) obj;
if (o.getValue() != null) {
try {
// return JSON.parse(o.getValue(), Map.class);
return mapper.readValue(o.getValue(), Map.class);
} catch (IOException e) {
e.printStackTrace();
}
}
return new HashMap();
}
@Override
public void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor sharedSessionContractImplementor) throws HibernateException, SQLException {
if (value == null) {
st.setNull(index, Types.OTHER);
} else {
try {
// st.setObject(index, JSON.toJSON(value), Types.OTHER);
st.setObject(index, mapper.writeValueAsString(value), Types.OTHER);
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Override
public Object deepCopy(Object originalValue) throws HibernateException {
if (originalValue != null) {
try {
// 替换为其他JSON解析器
// return JSON.parse(JSON.toJSON(originalValue), returnedClass());
return mapper.readValue(mapper.writeValueAsString(originalValue), returnedClass());
} catch (IOException e) {
throw new HibernateException("Failed to deep copy object", e);
}
}
return null;
}
@Override
public boolean isMutable() {
return true;
}
@Override
public Serializable disassemble(Object value) throws HibernateException {
Object copy = deepCopy(value);
if (copy instanceof Serializable) {
return (Serializable) copy;
}
throw new SerializationException(String.format("Cannot serialize '%s', %s is not Serializable.", value, value.getClass()), null);
}
@Override
public Object assemble(Serializable cached, Object o) throws HibernateException {
return deepCopy(cached);
}
@Override
public Object replace(Object original, Object target, Object owner) throws HibernateException {
return deepCopy(original);
}
}
- 在Entity上使用
import com.example.jsonb.config.JsonbListType;
import com.example.jsonb.config.JsonbType;
import lombok.Data;
import lombok.experimental.Accessors;
import org.hibernate.annotations.*;
import javax.persistence.*;
import javax.persistence.Entity;
import java.util.List;
import java.util.Map;
@Entity
@Data
@Accessors(chain = true)
@TypeDef(name = "JsonbType", typeClass = JsonbType.class)
public class Account {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@Column(columnDefinition = "jsonb")
@Type(type = "JsonbType")
private Map info;
}
5.定义repository
import com.example.jsonb.po.Account;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import java.util.List;
public interface AccountRepository extends JpaRepository {
@Query(value = "select * from account where info ->> 'name' = :name", nativeQuery = true)
List findByName(@Param("name") String name);
}
- 测试
import com.example.jsonb.po.Account;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.*;
@RunWith(SpringRunner.class)
@SpringBootTest
public class AccountRepositoryTest {
@Autowired
AccountRepository accountRepository;
@Before
public void setUp() throws Exception {
HashMap info = new HashMap<>();
info.put("name", "光头强");
info.put("age", 3);
info.put("tel", "110");
info.put("Hobby", Arrays.asList("吃饭", "睡觉", "砍树", "打豆豆"));
Account account = new Account().setInfo(info);
accountRepository.save(account);
}
@Test
public void findByName() {
List accounts = accountRepository.findByName("光头强");
System.out.println(accounts);
}
}
测试结果