mysql的josn类型映射到java是String

mysql有json类型,java通过String接收;

1.数据库查询显示:

2. java代码测试

    public static void main(String[] args) {
        // LinkedHashMap保证遍历的时候是存储顺序;
        Map<String, Integer> soldierNum = new LinkedHashMap<>();
        soldierNum.put("18-40岁", 77);
        soldierNum.put("41-65岁", 130);
        soldierNum.put("65岁以上", 146);
        String string = soldierNum.toString();
        System.out.println(string);

        // 遍历集合
        Set<Map.Entry<String, Integer>> entries = soldierNum.entrySet();
        for (Map.Entry<String, Integer> entry : entries) {
            System.out.println("key= " + entry.getKey() + " and value= "
                    + entry.getValue());
        }
        // map -> json
        String s = JSON.toJSONString(soldierNum);
        System.out.println(s);

    }

3.java对应数据库实体类

public class ExcelElement implements Serializable {
    private Long id;

    // TODO 记得自动将Sting -> map
    @Excel(name = "军人数量")
    private String soldierNum;

    private String orgRelationship;

    private Map<String, Object> soldierNumMap = new LinkedHashMap<>();

    private Map<String, Object> orgRelationshipMap = new LinkedHashMap<>();

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getSoldierNum() {
        return soldierNum;
    }

    public void setSoldierNum(String soldierNum) {
        this.soldierNum = soldierNum;
        // mybatis映射java对象的时候调用set方法,所以在这里我直接解析了json -> map
        this.setSoldierNumMap(JSON.parseObject(this.soldierNum, LinkedHashMap.class, Feature.OrderedField));
    }
}

JSON.parseObject(this.soldierNum, LinkedHashMap.class, Feature.OrderedField)保证了读取数据顺序和数据库存储顺序一致

4.postman返回数据展示:

5.应该没写完,以后有机会补充;

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本文地址：https://blog.csdn.net/weixin_42096620/article/details/110498135