MongoDB 取出文件遇到异常

oughl0007

前些天终于把文件塞进mongoDB里边了，然后开始考虑拉取。

public static void test1() {
    GridFS gfs=new GridFS(new DB(new MongoClient(),"listentome"));
    DBCursor cur=gfs.getFileList();
    int num=0;
    while(cur.hasNext())
    {
        GridFSDBFile dbf=(GridFSDBFile)cur.next();
        try {
            dbf.writeTo("E:/"+(num++)+".mp3");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

然而异常来了

Exception in thread "main" java.lang.IllegalStateException: No GridFS instance defined!
at com.mongodb.gridfs.GridFSDBFile.getChunk(GridFSDBFile.java:95)
at com.mongodb.gridfs.GridFSDBFile.writeTo(GridFSDBFile.java:88)
at com.mongodb.gridfs.GridFSDBFile.writeTo(GridFSDBFile.java:70)
at com.mongodb.gridfs.GridFSDBFile.writeTo(GridFSDBFile.java:56)
at com.listentome.DB.Operations.IDB.test1(IDB.java:112)
at com.listentome.DB.Operations.IDB.main(IDB.java:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)

22265

@oughl0007

你的版本和我不一樣... 我是

1. mongoClient.getDatabase()

2. GridFSBuckets.create(database)

3. gridBucket.uploadFromStream(fileName, inputStream, uploadOptions)