Mybatis-PLUS 自定义字段处理器

数据库 varchar 转换 Java 数组

typeHandler 除了处理数组转换还可以做很多事情，例如数据加密，插入数据库的时候加密，查询解密

entity类

/**
 * 

 * 
 * 
 *
 * @author Lizr
 * @since 2022-01-12
 */
@TableName(value = "t_merchants_project", autoResultMap = true)
@ApiModel(value = "TMerchantsProject对象", description = "")
public class TMerchantsProject implements Serializable {

    private static final long serialVersionUID = 1L;


    @ApiModelProperty("需要装换的属性")
    @TableField(typeHandler = JsonStringArrayTypeHandler.class)
    private String[] doc;
}

JsonStringArrayTypeHandler 字符串和数组互转

public class JsonStringArrayTypeHandler extends BaseTypeHandler<String[]> {
    private static final ObjectMapper mapper = new ObjectMapper();

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, String[] parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, toJson(parameter));
    }

    @Override
    public String[] getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return this.toObject(rs.getString(columnName));
    }

    @Override
    public String[] getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return this.toObject(rs.getString(columnIndex));
    }

    @Override
    public String[] getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return this.toObject(cs.getString(columnIndex));
    }

    private String toJson(String[] params) {
        try {
            return mapper.writeValueAsString(params);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "[]";
    }

    private String[] toObject(String content) {
        if (content != null && !content.isEmpty()) {
            try {
                return (String[]) mapper.readValue(content, String[].class);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else {
            return null;
        }
    }
}

JsonIntegerArrayTypeHandler ,字符串 转Integer 数组

javapublic class JsonIntegerArrayTypeHandler extends BaseTypeHandler<Integer[]> {
    private static final ObjectMapper mapper = new ObjectMapper();

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, Integer[] parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, toJson(parameter));
    }

    @Override
    public Integer[] getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return this.toObject(rs.getString(columnName));
    }

    @Override
    public Integer[] getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return this.toObject(rs.getString(columnIndex));
    }

    @Override
    public Integer[] getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return this.toObject(cs.getString(columnIndex));
    }

    private String toJson(Integer[] params) {
        try {
            return mapper.writeValueAsString(params);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "[]";
    }

    private Integer[] toObject(String content) {
        if (content != null && !content.isEmpty()) {
            try {
                return (Integer[]) mapper.readValue(content, Integer[].class);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else {
            return null;
        }
    }
}