具体代码如下所示：

package epoint.mppdb_01.h3c;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 = "h3c"; 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！"); }}

总结

以上所述是小编给大家介绍的mysql中blob数据处理方式，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！