MongoDB学习-->Gridfs分布式存储&DBRef关联查询

mongodb自带的一个分布式文件系统

fs.files _id filename md5 size uploaddate contenttype metadata {"user_id":1}

fs.chunks _id files_id n(序号) data

{ "metadata" : { "user_id" : 101} , "filename" : "video.min2.js" , "aliases" : null , "chunkSize" : 261120 , "uploadDate" : { "$date" : "2017-03-28T13:48:20.784Z"} , "length" : 282753 , "_id" : { "$oid" : "58da69a45aa6c70234eb70f1"} , "contentType" : null , "md5" : "e5ab0872d9b25fcb7268df3a93c29873"}

测试GridFs文件上传与下载

package com.tangzhe.gridfs;

import com.mongodb.BasicDBObject;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSFile;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.gridfs.GridFsTemplate;
import org.springframework.test.context.junit4.SpringRunner;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * Created by 唐哲
 * 2018-03-15 9:33
 * 测试GridFs文件上传与下载
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class GridFsTest {

    @Autowired
    private GridFsTemplate gridFsTemplate;

    /**
     * 测试GridFs文件上传
     */
    //@Test
    public void gridFsUpload() throws FileNotFoundException {
        //System.out.println(gridFsTemplate);
        File file = new File("D:\IdeaProjects\cxytiandi\mongodb-demo\upload.txt");
        GridFSFile gridFSFile = gridFsTemplate.store(new FileInputStream(file), file.getName(), new BasicDBObject("user_id", 101));
        System.out.println(gridFSFile.toString());
    }

    /**
     * 测试GridFs文件下载
     */
    //@Test
    public void gridFsDownload() throws IOException {
        GridFSDBFile gridFSDBFile = gridFsTemplate.findOne(Query.query(Criteria.where("_id").is("5aa9cf31d678412b40ff5ab4")));
        gridFSDBFile.writeTo("D:\IdeaProjects\cxytiandi\mongodb-demo\download.txt");
    }

}

DBRef关联查询

package com.tangzhe.dbref;

import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

/**
 * Created by 唐哲
 * 2018-03-15 16:19
 * DBRef关联查询
 */
@Document(collection = "class_info")
@Data
public class ClassInfo {

    @Id
    private String id;
    private String name;

}

package com.tangzhe.dbref;

import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.DBRef;
import org.springframework.data.mongodb.core.mapping.Document;

/**
 * Created by 唐哲
 * 2018-03-15 16:29
 * DBRef关联查询
 */
@Document(collection = "student")
@Data
public class Student {

    @Id
    private String id;
    private String name;
    @DBRef
    private ClassInfo classInfo;

}

package com.tangzhe.dbref;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
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.test.context.junit4.SpringRunner;

/**
 * Created by 唐哲
 * 2018-03-15 16:30
 * 测试DBRef关联查询
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class DbRefTest {

    @Autowired
    private MongoTemplate mongoTemplate;

    //@Test
    public void test1() {
        ClassInfo classInfo = new ClassInfo();
        classInfo.setName("三年一班");
        mongoTemplate.save(classInfo);

        Student student = new Student();
        student.setName("张三");
        student.setClassInfo(classInfo);
        mongoTemplate.save(student);
    }

    //@Test
    public void test2() {
        ClassInfo classInfo = mongoTemplate.findOne(Query.query(Criteria.where("id").is("5aaa30c0d678410bac20db1a")), ClassInfo.class);
        Student student = new Student();
        student.setName("李四");
        student.setClassInfo(classInfo);
        mongoTemplate.save(student);
    }

    //@Test
    public void test3() {
        Student student = mongoTemplate.findOne(Query.query(Criteria.where("id").is("5aaa30c0d678410bac20db1b")), Student.class);
        System.out.println(student);
    }

}