JsonConfig的jsonConfig.setExcludes的用法

1.问题描述

在项目中经常会有两个类存在一对多或者多对一的关联关系，这样在查询多的一方时，会深入查询关联的一方，而我们可能并不需要去深入查询那些数据，此时使用JsonConfig的jsonConfig.setExcludes过滤不需要转换的属性

2.举例

关联的类：

a:常用联系人

@Entity
@Table(name = "core_contacts")
public class Contacts implements java.io.Serializable{/**
     * 会员
     */
　　private Member member;
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "member")
    public Member getMember() {
        return member;
    }    public void setMember(Member member) {
        this.member = member;
    }}

b:会员类

@Entity
@Table(name = "core_member", uniqueConstraints = {
        @UniqueConstraint(columnNames = "user_account"), @UniqueConstraint(columnNames = "mobile"),
        @UniqueConstraint(columnNames = "email") })
public class Member implements java.io.Serializable {
　　//常用联系人
    private Set<Contacts> contacts = new HashSet<Contacts>(0);
    public Member(Set<Contacts> contacts) {       this.contacts = contacts;
    }    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "member")
    public Set<Contacts> getContacts() {
        return contacts;
    }    public void setContacts(Set<Contacts> contacts) {
        this.contacts = contacts;
    }
}

3.在根据会员查询常用联系人时，会深入查询会员的所有信息，此时需要过滤

@RequestMapping("loadSelect.html")
    public JSONMessageView loadSelect(HttpServletRequest request){
        JSONMessageView json=new JSONMessageView(BusinessConstant.ERR,"记载失败",null);
        Member member=super.getMember();
        try {
            List<Contacts> contactPersonLst=contactsService.getByMember(member);
            if (contactPersonLst==null) {
                contactPersonLst=new ArrayList<Contacts>();
            }
            Map<String, Object> map=new HashMap<String, Object>();
            JsonConfig jsonConfig = new JsonConfig();
            jsonConfig.setExcludes(new String[] { "member" });//过滤不需要转换的属性
            JSONArray contactPersonList=JSONArray.fromObject(contactPersonLst,jsonConfig);
            map.put("contactPersonLst", contactPersonList);
            json.setCode(BusinessConstant.OK);
            json.setMessage("加载成功");
            json.setContent(map);
            return json;
        } catch (Exception e) {
            e.printStackTrace();
            json.setMessage("加载异常");
            return json;
        }