@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})public @interface Comment {String value() default "";}package cn.com.micro.qx.comment;import org.hibernate.boot.Metadata;import org.hibernate.engine.spi.SessionFactoryImplementor;import org.hibernate.integrator.spi.Integrator;import org.hibernate.mapping.PersistentClass;import org.hibernate.mapping.Property;import org.hibernate.service.spi.SessionFactoryServiceRegistry;import org.springframework.stereotype.Component;import java.lang.reflect.Field;import java.util.Iterator;@Componentpublic class CommentIntegrator implements Integrator {public static final CommentIntegrator INSTANCE = new CommentIntegrator();public CommentIntegrator() {super();}/** * Perform comment integration. * * @param metadataThe "compiled" representation of the mapping information * @param sessionFactory The session factory being created * @param serviceRegistry The session factory's service registry */@Overridepublic void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {processComment(metadata);}/** * Not used. * * @param sessionFactoryImplementor The session factory being closed. * @param sessionFactoryServiceRegistry That session factory's service registry */@Overridepublic void disintegrate(SessionFactoryImplementor sessionFactoryImplementor, SessionFactoryServiceRegistry sessionFactoryServiceRegistry) {}/** * Process comment annotation. * * @param metadata process annotation of this {@code Metadata}. */private void processComment(Metadata metadata) {for (PersistentClass persistentClass : metadata.getEntityBindings()) {// Process the Comment annotation is applied to ClassClass clz = persistentClass.getMappedClass();if (clz.isAnnotationPresent(Comment.class)) {Comment comment = clz.getAnnotation(Comment.class);persistentClass.getTable().setComment(comment.value());}// Process Comment annotations of identifier.Property identifierProperty = persistentClass.getIdentifierProperty();if (identifierProperty != null) {fieldComment(persistentClass, identifierProperty.getName());} else {org.hibernate.mapping.Component component = persistentClass.getIdentifierMapper();if (component != null) {//noinspection uncheckedIterator iterator = component.getPropertyIterator();while (iterator.hasNext()) {fieldComment(persistentClass, iterator.next().getName());}}}// Process fields with Comment annotation.//noinspection uncheckedIterator iterator = persistentClass.getPropertyIterator();while (iterator.hasNext()) {fieldComment(persistentClass, iterator.next().getName());}}}/** * Process @{code comment} annotation of field. * * @param persistentClass Hibernate {@code PersistentClass} * @param columnNamename of field */private void fieldComment(PersistentClass persistentClass, String columnName) {try {Field field = persistentClass.getMappedClass().getDeclaredField(columnName);if (field.isAnnotationPresent(Comment.class)) {String comment = field.getAnnotation(Comment.class).value();String sqlColumnName= persistentClass.getProperty(columnName).getValue().getColumnIterator().next().getText();Iterator columnIterator = persistentClass.getTable().getColumnIterator();while (columnIterator.hasNext()) {org.hibernate.mapping.Column column = columnIterator.next();if (sqlColumnName.equalsIgnoreCase(column.getName())) {column.setComment(comment);break;}}}} catch (NoSuchFieldException | SecurityException ignored) {}}}package cn.com.micro.qx.config;import cn.com.geoscene.micro.qx.comment.CommentIntegrator;import org.hibernate.jpa.boot.spi.IntegratorProvider;import org.springframework.boot.autoconfigure.orm.jpa.HibernatePropertiesCustomizer;import org.springframework.stereotype.Component;import java.util.Collections;import java.util.Map;@Componentpublic class HibernateConfig implements HibernatePropertiesCustomizer {@Overridepublic void customize(Map hibernateProperties) {hibernateProperties.put("hibernate.use_sql_comments", true);hibernateProperties.put("hibernate.integrator_provider",(IntegratorProvider) () -> Collections.singletonList(CommentIntegrator.INSTANCE));}}package cn.com.micro.qx.entity;import cn.afterturn.easypoi.excel.annotation.Excel;import cn.com.geoscene.micro.qx.comment.Comment;import com.fasterxml.jackson.annotation.JsonFormat;import com.fasterxml.jackson.annotation.JsonProperty;import io.swagger.annotations.ApiModel;import io.swagger.annotations.ApiModelProperty;import lombok.Data;import org.hibernate.annotations.ColumnTransformer;import org.hibernate.validator.constraints.Length;import org.springframework.data.jpa.domain.support.AuditingEntityListener;import javax.persistence.*;import java.io.Serializable;import java.util.Date;@Entity@Table(name = "XQYL", schema = "sde")@EntityListeners(AuditingEntityListener.class)@Data@ApiModel(description = "院落单元信息")@Comment("院落单元信息")public class CellUnit implements Serializable {@Id@JsonProperty("objectid")@ApiModelProperty(value = "主键")@Comment("主键")@GeneratedValue(strategy = GenerationType.IDENTITY)private Long objectid;@Length(max = 20)@Excel(name = "XQYLDM")@JsonProperty("XQYLDM")@Column(name = "XQYLDM",length = 20)@Comment("小区院落代码")@ApiModelProperty(value = "小区院落代码")String XQYLDM;@Length(max = 100)@Excel(name = "XQYLMC")@JsonProperty("XQYLMC")@Column(name = "XQYLMC",length = 100)@Comment("小区院落名称")@ApiModelProperty(value = "小区院落名称")String XQYLMC;} 当postgres数据库的schema和table名称都是大写的时候，在
CommentIntegrator里面使用这个代码。问题是使用这个代码会报异常数据库超过连接数。暂时还没有想到办法解决。还有一个问题是，使用下面这个代码要先屏蔽下面的代码，执行程序先创建好了表，才能在重新运行程序执行添加注释的功能 private void processComment2(Metadata metadata, SessionFactoryImplementor sessionFactory) {for (PersistentClass persistentClass : metadata.getEntityBindings()) {Class clz = persistentClass.getMappedClass();String tableName = persistentClass.getTable().getName().toUpperCase();System.out.println("-----------table " + tableName);try {String schema = persistentClass.getTable().getSchema().toUpperCase();if (clz.isAnnotationPresent(Comment.class)) {Comment comment = clz.getAnnotation(Comment.class);String value = comment.value();if (StringUtils.isNotBlank(value)) {String sql = String.format("COMMENT ON TABLE \"%s\".\"%s\" IS '%s'", schema, tableName, value);try {sessionFactory.getServiceRegistry().getService(ConnectionProvider.class).getConnection().createStatement().execute(sql);} catch (SQLException e) {e.printStackTrace();}}}Property identifierProperty = persistentClass.getIdentifierProperty();if (identifierProperty != null) {fieldComment(persistentClass, identifierProperty.getName(), sessionFactory);} else {org.hibernate.mapping.Component component = persistentClass.getIdentifierMapper();if (component != null) {Iterator iterator = component.getPropertyIterator();while (iterator.hasNext()) {fieldComment(persistentClass, iterator.next().getName(), sessionFactory);}}}Iterator iterator = persistentClass.getPropertyIterator();while (iterator.hasNext()) {fieldComment(persistentClass, iterator.next().getName(), sessionFactory);}//sessionFactory.close();}catch (Exception e){e.printStackTrace();}}}