json存数据库时处理器，jsonHandler/jsonArrayHandler

class ObjectJsonHandler<T> extends BaseTypeHandler<T> { private Class<T> clazz; 　　

　　 /**构造函数*/ public ObjectJsonHandler(Class<T> clazz) { if (clazz == null) { throw new IllegalArgumentException("Type argument cannot be null"); } this.clazz = clazz; } private NameFilter nameFilter = (object, name, value) -> name; /** * 设置非空参数 */ @Override public void setNonNullParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException { ps.setString(i, JSON.toJSONString(parameter, nameFilter)); } /** * 根据列名，获取可以为空的结果 */ @Override public T getNullableResult(ResultSet rs, String columnName) throws SQLException { String sqlJson = rs.getString(columnName); if (null != sqlJson) { return JSONObject.parseObject(sqlJson, clazz); } return null; } /** * 根据列索引，获取可以为空的结果 */ @Override public T getNullableResult(ResultSet rs, int columnIndex) throws SQLException { String sqlJson = rs.getString(columnIndex); if (null != sqlJson) { return JSONObject.parseObject(sqlJson, clazz); } return null; } @Override public T getNullableResult(CallableStatement cs, int columnIndex) throws SQLException { String sqlJson = cs.getString(columnIndex); if (null != sqlJson) { return JSONObject.parseObject(sqlJson, clazz); } return null; } }

2、继承ObjectJsonHandler

<span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * @Author jijiecong
 * @Date 2021/4/20 11:49
 * @Version 1.0
 * @Description 评价扩展字段json处理器
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">class</span> EvaluationAttributesJsonHandler <span style="color: rgba(0, 0, 255, 1)">extends</span> ObjectJsonHandler<EvaluationAttributesEntity><span style="color: rgba(0, 0, 0, 1)"> {
    </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> EvaluationAttributesJsonHandler() {
        </span><span style="color: rgba(0, 0, 255, 1)">super</span>(EvaluationAttributesEntity.<span style="color: rgba(0, 0, 255, 1)">class</span><span style="color: rgba(0, 0, 0, 1)">);
    }
}</span>

 

二、List对象转JsonArray

1、继承BaseTypeHandler

覆盖setNonNullParameter()，getNullableResult()，getNullableResult()，getNullableResult()方法

**
 *<span style="color: rgba(0, 0, 0, 1)"> ObjectJsonArrayHandler
 </span>*<span style="color: rgba(0, 0, 0, 1)"> JSONArray处理类
 </span>*
 * @version v1.0.0
 * @date 2020/7/23
 */
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">class</span> ObjectJsonArrayHandler<T>  <span style="color: rgba(0, 0, 255, 1)">extends</span> BaseTypeHandler<List<T>><span style="color: rgba(0, 0, 0, 1)"> {
    </span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">final</span> Class<T><span style="color: rgba(0, 0, 0, 1)"> clazz;
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> ObjectJsonArrayHandler(Class<T><span style="color: rgba(0, 0, 0, 1)"> clazz) {
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (clazz == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
            </span><span style="color: rgba(0, 0, 255, 1)">throw</span> <span style="color: rgba(0, 0, 255, 1)">new</span> IllegalArgumentException("Type argument cannot be null"<span style="color: rgba(0, 0, 0, 1)">);
        } </span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)"> {
            </span><span style="color: rgba(0, 0, 255, 1)">this</span>.clazz =<span style="color: rgba(0, 0, 0, 1)"> clazz;
        }
    }
    @Override
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span> setNonNullParameter(PreparedStatement ps, <span style="color: rgba(0, 0, 255, 1)">int</span> i, List<T> ts, JdbcType jdbcType) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> SQLException {
        ps.setString(i, JSONArray.toJSONString(ts));
    }
    @Override
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> List<T> getNullableResult(ResultSet rs, String s) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> SQLException {
        String jsonArrayStr </span>=<span style="color: rgba(0, 0, 0, 1)"> rs.getString(s);
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (<span style="color: rgba(0, 0, 255, 1)">null</span> !=<span style="color: rgba(0, 0, 0, 1)"> jsonArrayStr) {
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> JSONArray.parseArray(jsonArrayStr).toJavaList(clazz);
        }
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    @Override
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> List<T> getNullableResult(ResultSet rs, <span style="color: rgba(0, 0, 255, 1)">int</span> i) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> SQLException {
        String jsonArrayStr </span>=<span style="color: rgba(0, 0, 0, 1)"> rs.getString(i);
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (<span style="color: rgba(0, 0, 255, 1)">null</span> !=<span style="color: rgba(0, 0, 0, 1)"> jsonArrayStr) {
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> JSONArray.parseArray(jsonArrayStr).toJavaList(clazz);
        }
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    @Override
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> List<T> getNullableResult(CallableStatement cs, <span style="color: rgba(0, 0, 255, 1)">int</span> i) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> SQLException {
        String jsonArrayStr </span>=<span style="color: rgba(0, 0, 0, 1)"> cs.getString(i);
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (<span style="color: rgba(0, 0, 255, 1)">null</span> !=<span style="color: rgba(0, 0, 0, 1)"> jsonArrayStr) {
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> JSONArray.parseArray(jsonArrayStr).toJavaList(clazz);
        }
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    }
}</span>

2、继承ObjectJsonArrayHandler

<span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * StringJsonArrayHandler
 *
 * </span><span style="color: rgba(128, 128, 128, 1)">@version</span><span style="color: rgba(0, 128, 0, 1)"> v1.0.0
 * @date 2020/8/11
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">class</span> StringJsonArrayHandler <span style="color: rgba(0, 0, 255, 1)">extends</span> ObjectJsonArrayHandler<String><span style="color: rgba(0, 0, 0, 1)"> {
    </span><span style="color: rgba(0, 0, 255, 1)">public</span> StringJsonArrayHandler(Class<String><span style="color: rgba(0, 0, 0, 1)"> clazz) {
        </span><span style="color: rgba(0, 0, 255, 1)">super</span>(String.<span style="color: rgba(0, 0, 255, 1)">class</span><span style="color: rgba(0, 0, 0, 1)">);
    }
}</span>

 

json存数据库时处理器，jsonHandler/jsonArrayHandler

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