1，List中的引用类型转Map

引入的Jar包:

　import java.util.Map;   　import com.google.common.base.Function;　import com.google.common.collect.Maps;

Maven依赖:　　

       
      
       com.google.guava
        
      
       guava
        
      
       19.0
      
     

具体实现:

List
     
       userDOs = new ArrayList<>();Map
      
        mapUsers = Maps.uniqueIndex(userDOs, new Function 
       
         () {  　　public Long apply(UserDO from) {  　　　　return from.getUid();}});
       
      
     

List
     
       userVos = getUserInfoById(userIds); Map
      
        mapUsers = Maps.uniqueIndex(userVos, new Function
       
        () {
       @Override     public String apply(UserVo input) {
           return input.getId();     } });