直接构建json串：[{"id":"1","name":"name1","password":"password1","remark":"remark1"},{"id":"2","name":"name2","password":"password2","remark":"remark2"},{"id":"3","name":"name3","password":"password3","remark":"remark3"}] 

json串 -> java对象：user1.id=1,user1.name=name1,user1.password=password1,user1.remark=remark1 

user2.id=2,user2.name=name2,user2.password=password2,user2.remark=remark2 

user3.id=3,user3.name=name3,user3.password=password3,user3.remark=remark3 

java对象 -> json串：[{"name":"name1","password":"password1","remark":"remark1"}] 

List-> json串：[{"id":1,"name":"name1","password":"password1","remark":"remark1"},{"id":2,"name":"name2","password":"password2","remark":"remark2"},{"id":3,"name":"name3","password":"password3","remark":"remark3"}] 

对象数组 -> json串：[{"id":1,"name":"name1","password":"password1","remark":"remark1"},{"id":2,"name":"name2","password":"password2","remark":"remark2"},{"id":3,"name":"name3","password":"password3","remark":"remark3"}]