MongoDB|Spring Data MongoDB（使用GridFS保存二进制文件） MongoDB|MongoDB

在MongoDB中，可以使用GridFS保存二进制文件。本文介绍如何使用GridFsTemplate保存和读取图片文件。
1. GridFS - 保存（使用Spring注解方式）

import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.mongodb.config.AbstractMongoConfiguration; import org.springframework.data.mongodb.gridfs.GridFsTemplate; import com.mongodb.Mongo; import com.mongodb.MongoClient; /** * Spring MongoDB configuration file * */ @Configuration public class SpringMongoConfig extends AbstractMongoConfiguration{@Bean public GridFsTemplate gridFsTemplate() throws Exception { return new GridFsTemplate(mongoDbFactory(), mappingMongoConverter()); }@Override protected String getDatabaseName() { return "yourdb"; }@Override @Bean public Mongo mongo() throws Exception { return new MongoClient("127.0.0.1"); }}

import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import org.springframework.context.ApplicationContext; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.data.mongodb.gridfs.GridFsOperations; import com.mkyong.config.SpringMongoConfig; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; /** * GridFs example * * @author zong * */public class GridFsAppStore {public static void main(String[] args) {ApplicationContext ctx = new AnnotationConfigApplicationContext(SpringMongoConfig.class); GridFsOperations gridOperations = (GridFsOperations) ctx.getBean("gridFsTemplate"); DBObject metaData = https://www.it610.com/article/new BasicDBObject(); metaData.put("extra1", "anything 1"); metaData.put("extra2", "anything 2"); InputStream inputStream = null; try { inputStream = new FileInputStream("/Users/mkyong/Downloads/testing.png"); gridOperations.store(inputStream, "testing.png", "image/png", metaData); } catch (FileNotFoundException e) { e.printStackTrace(); } finally { if (inputStream != null) { try { inputStream.close(); } catch (IOException e) { e.printStackTrace(); } } }System.out.println("Done"); }}

使用MongoDB控制台查看保存的文件：

> show dbs yourdb0.203125GB> use yourdb switched to db yourdb> show collections fs.chunks fs.files system.indexes> db.fs.files.find() { "_id" : ObjectId("51641c5630045c9b3db35afc"), "chunkSize" : NumberLong(262144), "length" : NumberLong(4238), "md5" : "9969527cd95a5a573f15e953f0036800", "filename" : "testing.png", "contentType" : "image/png", "uploadDate" : ISODate("2013-04-09T13:49:10.104Z"), "aliases" : null, "metadata" : { "extra1" : "anything 1", "extra2" : "anything 2" } } >> db.fs.chunks.find() { "_id" : ObjectId("51641c5630045c9b3db35afd"), "files_id" : ObjectId("51641c5630045c9b3db35afc"), "n" : 0, "data" : BinData(0,"/9j/4AAQSkZJRgABAgAAZ......EQH/9k=") }

【MongoDB|Spring Data MongoDB（使用GridFS保存二进制文件）】图片信息保存在fs.files，图片的二进制流保存在fs.chunks，通过_id和files_id关联。
2. GridFS - 读取（使用xml方式）

import java.io.IOException; import java.util.List; import org.springframework.context.ApplicationContext; import org.springframework.context.support.GenericXmlApplicationContext; import org.springframework.data.mongodb.core.query.Criteria; import org.springframework.data.mongodb.core.query.Query; import org.springframework.data.mongodb.gridfs.GridFsOperations; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.gridfs.GridFSDBFile; /** * GridFs example * * @author zong * */public class GridFsAppRead {public static void main(String[] args) {ApplicationContext ctx = new GenericXmlApplicationContext("SpringConfig.xml"); GridFsOperations gridOperations = (GridFsOperations) ctx.getBean("gridFsTemplate"); List result = gridOperations.find( new Query().addCriteria(Criteria.where("filename").is("testing.png"))); for (GridFSDBFile file : result) { try { System.out.println(file.getFilename()); System.out.println(file.getContentType()); //save as another image file.writeTo("/Users/mkyong/Downloads/new-testing.png"); } catch (IOException e) { e.printStackTrace(); } }System.out.println("Done"); } }