Mr. Yu Qing, the author of FastDFS, has developed a Corresponding SDK for Java for us. Some clarification: Author Yu Qing did not update the latest Java SDK to Maven’s central repository, which is still version 1.27. So we need to go to Github: github.com/happyfish10… Download the project source code, and then run the command MVN clean install to compile the package and import the Maven local repository for use.
Next, we use Java API operation FastDFS to achieve file upload, download, replace, delete, query metadata, query details and other functions.
The cases in this paper have been synchronized to:
- Github:github.com/imrhellowor…
- Gitee:gitee.com/imrhellowor…
Create a project
Add the dependent
Add the following dependencies to the project’s POM.xml. Because we need some common toolkits and unit tests, we need to introduce them.
<! -- fastdfs java client -->
<dependency>
<groupId>org.csource</groupId>
<artifactId>fastdfs-client-java</artifactId>
<version>1.29 the SNAPSHOT</version>
</dependency>
<! Apache Commons Lang3 toolkit -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.11</version>
</dependency>
<! -- Junit Unit Test -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
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Writing configuration files
fdfs_client.conf
Connect_timeout = 10 network_timeout = 30 charset = UTF-8 # tracker Specifies the server port exposed under the HTTP protocol Tracker_http_port = 8080 # tracker_server = 192.168.10.101:22122Copy the code
Utility class
package org.example.client;
import org.apache.commons.lang3.StringUtils;
import org.csource.common.MyException;
import org.csource.common.NameValuePair;
import org.csource.fastdfs.*;
import java.io.*;
/** * FastDFS Java client tools for distributed file system */
public class FastDFSClient {
// Get the configuration file address
private static final String CONF_FILENAME = Thread.currentThread()
.getContextClassLoader().getResource("").getPath() + "fdfs_client.conf";
// Storage Storage server client
private static StorageClient storageClient = null;
static {
try {
// Load the configuration file
ClientGlobal.init(CONF_FILENAME);
// Initialize the Tracker client
TrackerClient trackerClient = new TrackerClient(ClientGlobal.g_tracker_group);
// Initialize the Tracker server
TrackerServer trackerServer = trackerClient.getTrackerServer();
// Initialize the Storage server
StorageServer storageServer = trackerClient.getStoreStorage(trackerServer);
// Initialize the Storage client
storageClient = new StorageClient(trackerServer, storageServer);
} catch (IOException e) {
e.printStackTrace();
} catch(MyException e) { e.printStackTrace(); }}/** * File upload **@paramInputStream the byte inputStream of the uploaded file *@paramFileName Specifies the original name of the uploaded file *@return* /
public static String[] uploadFile(InputStream inputStream, String fileName) {
try {
// Prepare the byte array
byte[] fileBuff = null;
// File metadata
NameValuePair[] metaList = null;
if(inputStream ! =null) {
// Check the length of the file
int len = inputStream.available();
// Initialize the metadata array
metaList = new NameValuePair[2];
// The first set of metadata, the original name of the file
metaList[0] = new NameValuePair("file_name", fileName);
// The second set of metadata, the length of the file
metaList[1] = new NameValuePair("file_length", String.valueOf(len));
// Create an array of bytes of the corresponding length
fileBuff = new byte[len];
// Read bytes from the input stream into the byte array
inputStream.read(fileBuff);
}
/* Upload file. Parameter meanings: The content of the file to be uploaded (passed using a byte array), the type of the file to be uploaded (extension), and the metadata */
String[] fileids = storageClient.upload_file(fileBuff, getFileExt(fileName), metaList);
return fileids;
} catch (IOException e) {
e.printStackTrace();
} catch (MyException e) {
e.printStackTrace();
}
return null;
}
/** * File upload **@paramFile Uploaded file *@paramFileName Specifies the original name of the uploaded file *@return* /
public static String[] uploadFile(File file, String fileName) {
try (FileInputStream fis = new FileInputStream(file)) {
return uploadFile(fis, fileName);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/** * Gets the file name extension (without a dot) **@param fileName
* @returnFor example: "JPG" or "*/
private static String getFileExt(String fileName) {
if(StringUtils.isBlank(fileName) || ! fileName.contains(".")) {
return "";
}
return fileName.substring(fileName.lastIndexOf(".") + 1); // Without the last dot
}
/** * Get file details **@paramGroupName Group/volume name. Default value: group1 *@paramRemoteFileName filename, for example: "M00/00/00 / wKgKZl9tkTCAJAanAADhaCZ_RF0495. JPG" *@returnFile details */
public static FileInfo getFileInfo(String groupName, String remoteFileName) {
try {
return storageClient.get_file_info(groupName == null ? "group1" : groupName, remoteFileName);
} catch (IOException e) {
e.printStackTrace();
} catch (MyException e) {
e.printStackTrace();
}
return null;
}
/** * get metadata **@paramGroupName Group/volume name. Default value: group1 *@paramRemoteFileName filename, for example: "M00/00/00 / wKgKZl9tkTCAJAanAADhaCZ_RF0495. JPG" *@returnFile metadata array */
public static NameValuePair[] getMetaData(String groupName, String remoteFileName) {
try {
// Obtain the metadata array of the file from the Storage client based on the group name and file name
return storageClient.get_metadata(groupName == null ? "group1" : groupName, remoteFileName);
} catch (IOException e) {
e.printStackTrace();
} catch (MyException e) {
e.printStackTrace();
}
return null;
}
/** * File download **@paramGroupName Group/volume name. Default value: group1 *@paramRemoteFileName filename, for example: "M00/00/00 / wKgKZl9tkTCAJAanAADhaCZ_RF0495. JPG" *@returnFile's byte input stream */
public static InputStream downloadFile(String groupName, String remoteFileName) {
try {
// Get the byte array of the file from the Storage client based on the group name and filename
byte[] bytes = storageClient.download_file(groupName == null ? "group1" : groupName, remoteFileName);
// Returns the byte stream object
InputStream inputStream = new ByteArrayInputStream(bytes);
return inputStream;
} catch (IOException e) {
e.printStackTrace();
} catch (MyException e) {
e.printStackTrace();
}
return null;
}
/** * Delete file **@paramGroupName Group/volume name. Default value: group1 *@paramRemoteFileName filename, for example: "M00/00/00 / wKgKZl9tkTCAJAanAADhaCZ_RF0495. JPG" *@return0 indicates success; non-0 indicates failure */
public static int deleteFile(String groupName, String remoteFileName) {
int result = -1;
try {
// Delete a file from the Storage client based on the group name and file name
result = storageClient.delete_file(groupName == null ? "group1" : groupName, remoteFileName);
} catch (IOException e) {
e.printStackTrace();
} catch (MyException e) {
e.printStackTrace();
}
return result;
}
/** * Modifies an existing file **@paramOldGroupName oldGroupName *@paramOldFileName oldFileName *@paramFile New file *@paramFileName indicates a new fileName *@return* /
public static String[] modifyFile(String oldGroupName, String oldFileName, File file, String fileName) {
/ / upload first
String[] fileids = uploadFile(file, fileName);
if (fileids == null) {
return null;
}
/ / delete again
int delResult = deleteFile(oldGroupName, oldFileName);
if(delResult ! =0) {
return null;
}
returnfileids; }}Copy the code
test
File upload
// File upload
@Test
public void testUploadFile(a) {
String[] fileids = FastDFSClient.uploadFile(new File("D:/china.jpg"), "china.jpg");
for (String fileid : fileids) {
System.out.println("fileid = "+ fileid); }}Copy the codeThe return value:
fileid = group1
fileid = M00/00/00/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg
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File for details
// View file details
@Test
public void testGetFileInfo(a) {
FileInfo fileInfo = FastDFSClient.getFileInfo("group1"."M00/00/00/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg");
System.out.println("fileInfo = " + fileInfo);
}
Copy the codeThe return value:
FileInfo = fetch_froM_server = false, file_type = 1, source_IP_ADDR = 192.168.10.102, file_size = 57704, create_timestamp = 2020-09-28 08:44:08, crc32 = 645874781Copy the code
File metadata
// Get file data
@Test
public void testGetMetaData(a) {
NameValuePair[] metaDatas = FastDFSClient.getMetaData("group1"."M00/00/00/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg");
for (NameValuePair metaData : metaDatas) {
System.out.println(metaData.getName() + "-"+ metaData.getValue()); }}Copy the codeThe return value:
file_length---57704
file_name---china.jpg
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File download
// File download
@Test
public void testDownloadFile(a) {
InputStream is = FastDFSClient.downloadFile("group1"."M00/00/00/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg");
try (FileOutputStream fos = new FileOutputStream("D:/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg")) {
int len = 0;
byte[] bytes = new byte[1024];
while((len = is.read(bytes)) ! = -1) {
fos.write(bytes, 0, len); fos.flush(); }}catch (FileNotFoundException e) {
e.printStackTrace();
} catch(IOException e) { e.printStackTrace(); }}Copy the code
File deletion
// Delete files
@Test
public void testDeleteFile(a) {
int result = FastDFSClient.deleteFile("group1"."M00/00/00/wKgKZl9xMdiAcOLdAADhaCZ_RF0096.jpg");
System.out.println("result = " + result);
}
Copy the codeThe return value:
result = 0
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File to replace
// File replacement
@Test
public void testModifyFile(a) {
String[] fileids = FastDFSClient.modifyFile("group1"."M00/00/00/wKgKZl9xOS2ASdu8AADhaCZ_RF0898.jpg".new File("D:/mhw.jpg"), "mhw.jpg");
for (String fileid : fileids) {
System.out.println("fileid = "+ fileid); }}Copy the codeThe return value:
fileid = group1
fileid = M00/00/00/wKgKZl9xOeaAFO00AACmo7QBGtA298.jpg
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So far the Java client FastDFS operation to achieve file upload, download, replace and delete operations to here, next we take you to build FastDFS cluster environment, multiple Tracker multiple Storage and then through the Nginx agent.
This article is licensed under a Creative Commons attribution – Noncommercial – No Deductive 4.0 International license.
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