org.springframework.boot
spring-boot-starter-data-mongodb
org.projectlombok
lombok
true
2、新建实体类
注：
1、使用了lombock
2、@document(collection = “letters”)
3、@Id :
@Id private String id; //对应主键 _id
collection=“letters” 表示你要存入到MongoDB 的那个集合中：这里就是指letters集合
@document(collection = "letters")
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Letter {
@Id
private String id;
private Integer userid;
private String nickname;
private String title;
private String content;
private String ctime;
private String stime;
}
3、编写Service
package cn.xhubbq.service.letter;
import cn.xhubbq.pojo.letter.Letter;
import com.mongodb.client.result.DeleteResult;
import java.util.List;
public interface ILetterService {
//写信
Letter addLetter(Letter letter);
//删除
DeleteResult deleteLetterById(String id);
//查询所有
List selectAllLetters();
//分页查询
List selectLettersByPage(int curPage,int pageSize);
//查总数
long letterCount();
}
package cn.xhubbq.service.letter;
import cn.xhubbq.pojo.letter.Letter;
import com.mongodb.client.result.DeleteResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class LetterServiceImpl implements ILetterService{
@Autowired
private MongoTemplate mongoTemplate;
@Override
public Letter addLetter(Letter letter) {
return mongoTemplate.insert(letter);
}
@Override
public List selectAllLetters() {
return mongoTemplate.findAll(Letter.class,"letters");
}
@Override
public List selectLettersByPage(int curPage, int pageSize) {
Query query=new Query();//Query是条件构造器
//从第1页开始
//分页查询，query.skip((curPage-1)*size).limit(size)表示跳过（当前页-1）*每页的大小条数据，输出size条数据
return mongoTemplate.find(query.skip((curPage-1)*pageSize).limit(pageSize),Letter.class);
}
@Override
public DeleteResult deleteLetterById(String id) {
Query query=new Query(Criteria.where("_id").is(id));
return mongoTemplate.remove(query,Letter.class);
}
@Override
public long letterCount() {
Query query=new Query();
return mongoTemplate.count(query,Letter.class);
}
}
说明：
Query query=new Query(Criteria.where("_id").is(id));
这很好理解： 查询 _id == id 的文档
也可以：使用 .and() 连接多个条件
Query query=new Query(Criteria.where("_id").is(id).and().where("name").is("你的名字"));
remove会返回一个DeleteResult 里面包含了删除数据的条数，可一通过 ’ . ’ 的方式来验证。
mongoTemplate.remove(query,Letter.class);
分页查询需要新建一个实体类来控制：
package cn.xhubbq.pojo.page;
import cn.xhubbq.pojo.letter.Letter;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.util.List;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class LetterPage {
private long totalpage;//总页数
private long currentpage;//当前页
private long totalcount;//总数
private long pagesize;//页面大小
private List letters;
public void setPagesize(int psize){
this.pagesize=psize;
totalpage=totalcount%pagesize!=0?totalcount/pagesize+1:totalcount/pagesize;//这段代码一定要在pagesize复制后执行
}
}
4、编程Controller来测试
package cn.xhubbq.controller.letter;
import cn.hutool.extra.ssh.JschRuntimeException;
import cn.xhubbq.pojo.letter.Letter;
import cn.xhubbq.pojo.page.LetterPage;
import cn.xhubbq.service.letter.LetterServiceImpl;
import com.alibaba.fastjson.JSONObject;
import com.mongodb.client.result.DeleteResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@RestController
public class LetterController {
@Autowired
private LetterServiceImpl letterService;
private static final int PAGE_SIZE=5;
@ResponseBody
@RequestMapping("/addLetter")
public Object addLetter(){
Letter letter=new Letter("xadgjadbhjas",1,"小翟","titlename","content__is","创建时间","发布时间");
List lst=new ArrayList<>();
for(int i=0;i<10;++i){
lst.add(new Letter("xadgjadbhjas"+('a'*i),i+1,"小翟"+i,"titlename"+i,"content__is","创建时间","发布时间"));
}
for (Letter let : lst) {
letterService.addLetter(let);
}
return lst;
}
@ResponseBody
@RequestMapping("/findLetters")
public List findLetter(){
return letterService.selectAllLetters();
}
@ResponseBody
@RequestMapping("/letterPage/{curPage}")
public Object letterPage(@PathVariable int curPage){
LetterPage letterPage=new LetterPage();
letterPage.setCurrentpage(curPage);
letterPage.setTotalcount(letterService.letterCount());//查总数
letterPage.setPagesize(PAGE_SIZE);
List letters=letterService.selectLettersByPage(curPage,PAGE_SIZE);
letterPage.setLetters(letters);
return letterPage;
}
@ResponseBody
@RequestMapping("/deleteLetter/{id}")
public String deleteLetter(@PathVariable String id){
Map map=new HashMap<>();
if(id!=null){
DeleteResult deleteResult = letterService.deleteLetterById(id);
if (deleteResult!=null){
return JSONObject.toJSONString(deleteResult);
}
map.put("state",0);
map.put("info","error");
return JSONObject.toJSONString(map);
}
map.put("state",0);
map.put("info","error");
return JSONObject.toJSONString(map);
}
}
说明：
使用了restful风格：也就是访问的时候不是 用问号传参 而是：
例如： @RequestMapping("/deleteLetter/{id}")
是：localhost:8080/deleteLetter/1
而不是：localhost:8080/deleteLetter?id=1
使用阿里巴巴的fastJson：
依赖：
com.alibaba
fastjson
1.2.14
云服务器上安装MongoDB
