先上DO代码:
@Data
@TableName("dict")
public class DictDo {
@TableId(type=IdType.AUTO)
private String id;
@TableField("`key`")
private String key;
private String value;
private String memo;
}
此处使用了lombok,自动生成对象方法(此处是否与我们的思想有异曲同工之妙呢)!
使用原生的查询条件拼装:
public List<DictDo> selectListEq(DictDo one) {
QueryWrapper<DictDo> wrapper = new QueryWrapper<>();
if (null != one.getId()) {
wrapper.eq("id", one.getId());
}
if (null != one.getKey() && !"".equals(one.getKey())) {
wrapper.eq("`key`", one.getKey());
}
if (null != one.getValue() && !"".equals(one.getValue())) {
wrapper.eq("value", one.getValue());
}
if (null != one.getMemo() && !"".equals(one.getMemo())) {
wrapper.eq("memo", one.getMemo());
}
return dictDao.selectList(wrapper);
}
如上所示,每个对象如果只有几条属性还好说,但是如果有几十条属性呢?
我们应该想到所有重复的劳动都是低价值的、可以被替代的!
工具代码:
public static QueryWrapper parseQuery(Object service) throws Exception {
QueryWrapper<Object> wrapper = new QueryWrapper<>();
Class<? extends Object> doClass = service.getClass();
Method[] methods = doClass.getDeclaredMethods();
Field[] fields = doClass.getDeclaredFields();
for (Field field : fields) {
for (Method method : methods) {
if (method.getName().equalsIgnoreCase("get" + field.getName())) {
String value = doClass.getDeclaredMethod(method.getName()).invoke(service) == null ? ""
: (String) doClass.getDeclaredMethod(method.getName()).invoke(service);
if (null != value && !"".equals(value)) {
wrapper.eq("`"+field.getName()+"`", doClass.getDeclaredMethod(method.getName()).invoke(service));
break;
}
}
}
}
return wrapper;
}
Service进行调用:
/**
* 按对象属性匹配
* @throws Exception
*/
public List<DictDo> selectListEq(DictDo one) throws Exception {
QueryWrapper<DictDo> wrapper = ParamSettingUtil.parseQuery(one);
return dictDao.selectList(wrapper);
}
进行测试:
@SuppressWarnings("unchecked")
@Test
public void testSelect() {
System.out.println("## testSelect");
DictDo dictDo=new DictDo();
dictDo.setKey("233");
QueryWrapper<DictDo> wrapper;
try {
wrapper = ParamSettingUtil.parseQuery(dictDo);
List<DictDo> dictDos= dictDao.selectList(wrapper);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
测试结果:
![](https://img.laitimes.com/img/__Qf2AjLwojIjJCLyojI0JCLicmbw5SN3YDOyE2M3UTZyM2NwcjYkRmM0IGNlVmZ2QWO0ETYj9CX5d2bs92Yl1iclB3bsVmdlR2LcNWaw9CXt92Yu4GZjlGbh5yYjV3Lc9CX6MHc0RHaiojIsJye.png)
如上图看到,我们新加进去的条件已经生效了!