mongodb文件上传下载删除查询

在mongo-java-driver3.x以上的版本中逐渐弃用了Mongo和getDB等一系列方法，所以原来的GridFS的用法也发生了一些改变

改进前：

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.MongoClient;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;

public class GridTest {

private static final Logger log = LoggerFactory.getLogger(GridTest.class);

public static void main(String[] args) throws FileNotFoundException{
	// 连接到 mongodb 服务
    @SuppressWarnings("resource")
	MongoClient mongoClient = new MongoClient( "localhost" , 27017 );
    @SuppressWarnings("deprecation")
	DB db = mongoClient.getDB("test");
	log.info("成功连接数据库");
    String collectionName="mongoCollectionTest";  
    GridFS gridFS = new GridFS(db,collectionName);
    
    /* 
     * 2、上传文件 
     */  
    //创建测试文件，mongo 默认存在该文件  
    File file=new File("E:-----------.pdf");  
    FileInputStream fileInputStream=new FileInputStream(file);  
    //创建gridFS文件数据流  
    GridFSInputFile createFile=gridFS.createFile(fileInputStream);  
      
    //设置文件属性  
    createFile.put("filename", "123.pdf");  
    createFile.put("contentType", "application/pdf");  
    createFile.save(); 
    
    /* 
     * 3、根据id查询上传文件 
     */  
    GridFSDBFile findOne= gridFS.findOne(new BasicDBObject("_id",createFile.getId()));  
    System.out.print(findOne);
}

}

改进后：

import com.mongodb.MongoClient;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSBuckets;
import com.mongodb.client.gridfs.model.GridFSUploadOptions;

import org.bson.Document;
import org.bson.types.ObjectId;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.util.UUID;

public class MongoDBTest {
private static Logger log = LoggerFactory.getLogger(MongoDbUtil.class);

private static final class MongoInstance {
	public final static MongoClient client;
	static {
		client = new MongoClient("localhost", 27017);
	}
}

public static MongoDatabase getDatabase(String databaseName) {
	return MongoInstance.client.getDatabase(databaseName);
}

/**
 * 上传文件
 * @param file
 * @param databaseName
 * @return
 */
public static String uploadFileToGridFS(File file,String databaseName) {
	InputStream in = null;
	String returnId = null;
	String pathName = file.getPath();
	String[] pathNameArray = pathName.split("\\\\");
    String[] name = pathNameArray[pathNameArray.length-1].split("\\.");
	String filename = name[0];
	String type = name[name.length-1];
	try {
		in = new FileInputStream(file);
		GridFSBucket bucket = GridFSBuckets.create(getDatabase(databaseName));
		GridFSUploadOptions options = new GridFSUploadOptions();
		//设置除filename以为的其他信息
		Document metadata = new Document();
		metadata.append("contentType", type);
		options.metadata(metadata);
		ObjectId fileId = bucket.uploadFromStream(filename+type, in,options);
		returnId = fileId.toHexString();
		log.info("文件上传成功");
	} catch (IOException e) {
		log.info("upload fail:" + e);
	} finally {
		try {
			in.close();
		} catch (IOException e) {
			log.info("close inputstream fail:" + e);
		}
	}
	return returnId;
}

/**
 * 通过objectid和file下载文件
 * @param objectId
 * @param file
 * @param databaseName
 */
public static void downloadFile(String objectId, File file,String databaseName) {
	OutputStream os = null;
	try {
		os = new FileOutputStream(file);
		GridFSBucket bucket = GridFSBuckets.create(getDatabase(databaseName));
		bucket.downloadToStream(new ObjectId(objectId), os);
		log.info("文件下载成功");
	} catch (IOException e) {
		log.info("download fail:" + e);
	} finally {
		if (os != null) {
			try {
				os.close();
			} catch (IOException e) {
				log.info("close outputstream fail:" + e);
			}
		}
	}
}

/**
 * 通过objectid删除文件
 * @param objectId
 * @param databaseName
 */
public static void deleteByObjectId(String objectId,String databaseName) {
	GridFSBucket bucket = GridFSBuckets.create(getDatabase(databaseName));
	bucket.delete(new ObjectId(objectId));
	log.info("文件删除成功");
}


/**
 * 查询文件
 * @param databaseName
 */
public static List find(String databaseName){
	GridFSBucket bucket = GridFSBuckets.create(getDatabase(databaseName));
	GridFSFindIterable iterable = bucket.find();
	MongoCursor mongoCursor= iterable.iterator();
	List results = new ArrayList(); 
	while(mongoCursor.hasNext()){
		results.add(mongoCursor.next());
	}
	return results;
}

/**
 * 查询文件
 * @param databaseName
 */
public static List findBy(String databaseName,Bson filter){
	GridFSBucket bucket = GridFSBuckets.create(getDatabase(databaseName));
	GridFSFindIterable iterable = bucket.find(filter);
	MongoCursor mongoCursor= iterable.iterator();
	List results = new ArrayList(); 
	while(mongoCursor.hasNext()){
		results.add(mongoCursor.next());
	}
	return results;
}

}
import java.io.File;
import org.junit.Test;

public class MongoGridFSTest
{

/**
 * 先上传
 */
@Test
public void upload() {
	File file = new File("C:/Users/Administrator/Desktop/Java持久化之myBatis3.pdf");
	String databaseName = "test";
	String objectId = MongoDbFSUtil.uploadFileToGridFS(file,databaseName);
	System.out.println(objectId);
	System.out.println("文件上传成功");
}

/**
 * 测试下载
 */
@Test
public void download() {
	//System.out.println(objectId);
	File file = new File("D:/1.pdf");
	String databaseName = "test";
	MongoDbFSUtil.downloadFile("594b8298932ed623249dea18", file,databaseName);
	System.out.println("文件下载成功");
}

/**
 * 最后将上传的信息删除
 */
@Test
public void delete() {
	String databaseName = "test";
	MongoDbFSUtil.deleteByObjectId("594b3b53932ed60b043ac4c8",databaseName);
}

 
@Test
public void find(){
	List results= MongoDbFSUtil.find("test");
	for(GridFSFile file: results){
		System.out.println(file.toString());
	}
}


@Test
public void findBy(){
	Document filter = new Document();
	filter.append("filename", "深入理解Java虚拟机：JVM高级特性与最佳实践.pdf");
	List results= MongoDbFSUtil.findBy("test",filter);
	for(GridFSFile file: results){
		System.out.println(file.getId());
	}
}

}