• List对象装一个Map<String,String>

在Java8中新增了stream流的操作,对于代码书写更为简便,而且更容易看的懂

List<Unit> unitList = UnitMapper.selectList(queryWrapper);
Map<String, String> map = unitList.stream().collect(Collectors.toMap(Unit::getStrGuid, Unit::getStrUnit));

• List对象转一个Map<String,Object>

List<Unit> unitList = UnitMapper.selectList(queryWrapper);
unitList.stream().collect(Collectors.toMap(Unit::getStrGuid, Function.identity()));

Function.identity()返回一个跟输入一样的对象，等价于t -> t , 直接放在map的value

List<Unit> unitList = UnitMapper.selectList(queryWrapper);
unitList.stream().collect(Collectors.toMap(Unit::getStrGuid, Unit ->Unit));

这两种效果就是一样的了.