今天就跟大家聊聊有关mysql中怎么处理blob数据，可能很多人都不太了解，为了让大家更加了解，小编给大家总结了以下内容，希望大家根据这篇文章可以有所收获。
具体代码如下所示：
package epoint.mppdb_01.h4c;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
public class MySQLblobToMPPphoto {
// MySQL连接
public static Connection getMySQLConnection() throws Exception {
String MySQLDRIVER = "com.mysql.jdbc.Driver";
String MySQLURL = "jdbc:mysql://192.168.186.13:3306/bigdata_scene03_rktj";
String MySQLUSERNAME = "root";
String MySQLPASSWORD = "Gepoint";
Connection MySQLconn = DriverManager.getConnection(MySQLURL, MySQLUSERNAME, MySQLPASSWORD);
return MySQLconn;
}
// MPP连接
public static Connection getMPPConnection() throws Exception {
String MPPDRIVER = "com.MPP.jdbc.Driver";
String MPPURL = "jdbc:MPP://192.168.186.14:5258/bigdata_scene03_rktj";
String MPPUSERNAME = "mpp";
String MPPPASSWORD = "h4c";
Connection MPPconn = DriverManager.getConnection(MPPURL, MPPUSERNAME, MPPPASSWORD);
return MPPconn;
}
//
public static void getMySQLblobToHDFS() throws Exception {
Connection conn = getMySQLConnection();
ResultSet rs = null;
try {
String sql = "select ROW_ID,photo from t_rk_baseinfo_blob limit 10";
Statement prest = conn.prepareStatement(sql);
rs = prest.executeQuery(sql);
while (rs.next()) {
int row_id = rs.getInt(1);
Blob photo = rs.getBlob(2);
System.out.println(row_id + " " + photo);
InputStream in = photo.getBinaryStream();
OutputStream out = new FileOutputStream("H:/photo/" + row_id + ".jpg");
int len = 0;
byte[] buffer = new byte[1024];
while ((len = in.read(buffer)) != -1) {
out.write(buffer, 0, len);
}
upload("H:/photo/" + row_id + ".jpg");
}
prest.close();
rs.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭连接
if (conn != null) {
try {
conn.close();
conn = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) throws Exception {
getMySQLblobToHDFS();
}
// HDFS附件上传
public static void upload(String uploadpath) throws Exception {
Configuration conf = new Configuration();
URI uri = new URI("hdfs://192.168.186.14:8020");
FileSystem fs = FileSystem.get(uri, conf, "HDFS");
Path resP = new Path(uploadpath);
Path destP = new Path("/photo");
if (!fs.exists(destP)) {
fs.mkdirs(destP);
}
fs.copyFromLocalFile(resP, destP);
fs.close();
System.out.println("***********************");
System.out.println("上传成功！");
}
// HDFS附件下载
public static void download() throws Exception {
Configuration conf = new Configuration();
String dest = "hdfs://192.168.186.14:/photo/11.png";
String local = "D://11.png";
FileSystem fs = FileSystem.get(URI.create(dest), conf, "hdfs");
FSDataInputStream fsdi = fs.open(new Path(dest));
OutputStream output = new FileOutputStream(local);
IOUtils.copyBytes(fsdi, output, 4096, true);
System.out.println("***********************");
System.out.println("下载成功！");
}
}看完上述内容，你们对mysql中怎么处理blob数据有进一步的了解吗？如果还想了解更多知识或者相关内容，请关注亿速云行业资讯频道，感谢大家的支持。
