JDBC Handles Big Data

1. Handle large text

1  PackageCom.demo;2 3 ImportJava.io.File;4 Importjava.io.FileNotFoundException;5 ImportJava.io.FileReader;6 ImportJava.io.FileWriter;7 Importjava.io.IOException;8 ImportJava.io.Reader;9 Importjava.sql.Connection;Ten Importjava.sql.PreparedStatement; One ImportJava.sql.ResultSet; A Importjava.sql.SQLException; -  - Importorg.junit.Test; the  - Importcom.utils.DButils; -  - //JDBC to save large text data +  -  Public classDemo1 { + @Test A      Public voidInsert ()throwsSQLException, filenotfoundexception{ atConnection con =NULL; -PreparedStatement st =NULL; -ResultSet result =NULL; -         Try { -Con =dbutils.getconnection (); -String sql = "INSERT into Testclob (Id,resume) VALUES (?,?)"; inSt =con.preparestatement (SQL); -St.setstring (1, "1"); to              +File File =NewFile ("Src/1.txt"); -FileReader reader =Newfilereader (file); the              *             //set columns for large text $St.setcharacterstream (2, Reader, File.length ());Panax Notoginseng             intnum =st.executeupdate (); -             if(num>0){ theSystem.out.println ("Insert succeeded"); +             } A}finally{ the dbutils.release (Con, St, result); +         } -     } $      $     //reading large text data - @Test -      Public voidRead ()throwsSQLException, ioexception{ theConnection con =NULL; -PreparedStatement st =NULL;WuyiResultSet result =NULL; the          -         Try { WuCon =dbutils.getconnection (); -String sql = "Select Id,resume from Testclob where id= ' 1 '"; AboutSt =con.preparestatement (SQL); $result =st.executequery (); -             if(Result.next ()) { -                 //String resume = Result.getstring ("Resume"), cannot be saved with string, takes up too much memory -Reader reader = Result.getcharacterstream ("Resume"); AFileWriter writer =NewFileWriter ("C:\\1.text"); +                 Try{ the                     intLen = 0; -                     CharBuffer[] =New Char[1024]; $                      while(Len=reader.read (buffer)) >0){ theWriter.write (buffer, 0, Len); the                     } the}finally{ the                     if(reader!=NULL){ - reader.close (); in                     } the writer.close (); the                 } About             } the}finally{ the dbutils.release (Con, St, result); the         } +     } -      the}

2. Processing binary files

1  PackageCom.demo;2 3 ImportJava.io.File;4 ImportJava.io.FileInputStream;5 Importjava.io.FileNotFoundException;6 ImportJava.io.FileOutputStream;7 Importjava.io.IOException;8 ImportJava.io.InputStream;9 ImportJava.io.OutputStream;Ten Importjava.sql.Connection; One Importjava.sql.PreparedStatement; A ImportJava.sql.ResultSet; - Importjava.sql.SQLException; -  the Importorg.junit.Test; -  - Importcom.utils.DButils; -  + //JDBC Access binary files -  Public classDemo2 { + @Test A      Public voidInsert ()throwsSQLException, filenotfoundexception{ atConnection con =NULL; -PreparedStatement st =NULL; -ResultSet result =NULL; -         Try{ -Con =dbutils.getconnection (); -String sql = "INSERT into Testblob (id,image) VALUES (?,?)"; inSt =con.preparestatement (SQL); -St.setstring (1, "1"); toFile File =NewFile ("Src/1.jpg"); +FileInputStream in =Newfileinputstream (file); -St.setbinarystream (2, in, File.length ()); the st.executeupdate (); *}finally{ $ dbutils.release (Con, St, result);Panax Notoginseng         } -     } the      + @Test A      Public voidRead ()throwsSQLException, ioexception{ theConnection con =NULL; +PreparedStatement st =NULL; -ResultSet result =NULL; $         Try{ $Con =dbutils.getconnection (); -String sql = "Select Id,image from Testblob where id= ' 1 '"; -St =con.preparestatement (SQL); theresult =st.executequery (); -             if (Result.next ()) {InputStream in = Result.getbinarystream ("image"); OutputStream                      out = new FileOutputStream ("C:\\1.jpg"), try{54 int len = 0;55 byte[] buffer = new byte[1024];56 while ((Len=in.read (buffer)) >0) {in.                         Write (buffer, 0, Len),}59}finally{60 if (in!=null) {61 In.close ();}63 if (out!=null) {Out.clo Se ();}66}67} the}finally{ the dbutils.release (Con, St, result); -         } in     } the}

JDBC Handles Big Data