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  • vue

    1、问题,如下图,使用iviewui中的card导致页面不能出现滚动条(不太会弄,在网上查了一个vue组件vuescroll,因此使用这个做滚动条)

    2、安装vuescroll

     cnpm install -S vuescroll

    https://vuescrolljs.yvescoding.org/zh/guide/getting-started.html#%E5%AE%89%E8%A3%85

    3、问题:项目使用的jpa操作数据库,因为postclass和post是多堆多的关系,因此post.java和postclass.java如下,

    package com.nxz.blog.entity;
    
    import lombok.Data;
    import org.hibernate.annotations.GenericGenerator;
    
    import javax.persistence.*;
    import java.util.HashSet;
    import java.util.Set;
    
    @Entity
    @Data
    public class Post {
    
        @Id
        @GeneratedValue(generator = "system-uuid")
        @GenericGenerator(name = "system-uuid", strategy = "uuid")
        @Column(length = 32)
        private String postId;
    
        private String postTitle;
    
        @Lob
        private String postContent;
    
        /**
         * 摘要,也就是content的前100个字符
         */
        private String postRemark;
    
        private Long createDate;
    
        private Long updateDate;
    
        @ManyToMany(fetch = FetchType.LAZY)
        @JoinTable(name = "post_postclass", joinColumns = {@JoinColumn(name = "post_id")}, inverseJoinColumns = {@JoinColumn(name = "post_class_id")})
        private Set<PostClass> postClasses = new HashSet<>();
    
    }
    package com.nxz.blog.entity;
    
    import lombok.Data;
    import org.hibernate.annotations.GenericGenerator;
    
    import javax.persistence.*;
    import java.util.HashSet;
    import java.util.Set;
    
    @Entity
    @Data
    public class PostClass {
    
        @Id
        @GeneratedValue(generator = "system-uuid")
        @GenericGenerator(name = "system-uuid", strategy = "uuid")
        @Column(length = 32)
        private String classId;
    
        @Column(unique = true,length = 50)
        private String className;
    
        @ManyToMany(mappedBy = "postClasses", fetch = FetchType.LAZY)
        private Set<Post> posts = new HashSet<>();
    
    }

    但是当调用post.getPostclasses时会出错,会循环输出一下内容:

    HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@15e337b2<rs=com.alibaba.druid.pool.DruidPooledResultSet@4ee3a800>
    2019-06-11 21:30:16.860  WARN 33728 --- [nio-8888-exec-1] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@6fcf2b5b<rs=com.alibaba.druid.pool.DruidPooledResultSet@2547c902>
    2019-06-11 21:30:16.860  WARN 33728 --- [nio-8888-exec-1] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@2a4c60ce<rs=com.alibaba.druid.pool.DruidPooledResultSet@21504902>
    2019-06-11 21:30:16.860  WARN 33728 --- [nio-8888-exec-1] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@7b7ad7b1<rs=com.alibaba.druid.pool.DruidPooledResultSet@6f290408>
    2019-06-11 21:30:16.860  WARN 33728 --- [nio-8888-exec-1] o.h.e.loading.internal.LoadContexts      : H

    经过查询资料:https://stackoverflow.com/questions/54946083/jpa-bidirectional-mapping-not-fetching-deep-mapped-data

    得知,这个应该是lombok注解@Data导致的,具体原因没有查明,把这个注解去掉,同时自己手写get、set方法和tostring方法,就可以了

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  • 原文地址:https://www.cnblogs.com/nxzblogs/p/11012633.html
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