Db2csv about the learning of spring batch

The previous article has described how to import the contents of a CSV file into a database, and we'll look at how to export the data in the database to a CSV file

On the basis of the previous article, we will not re-create the MAVEN project without new additions.

First in the original project above the Java package to create a new configuration, to configure the job's related content, for the above article, we named Configuration_db_2_csv, the code is as follows:

1 @Configuration2 @EnableBatchProcessing3  Public classConfiguration_db_2_csv {4 @Bean5      PublicItemreader<user>Reader (DataSource DataSource) {6jdbccursoritemreader<user> reader =NewJdbccursoritemreader<user>();7 Reader.setdatasource (dataSource);8Reader.setsql ("Select User_id,user_name,address,birth,gender from User");9Reader.setrowmapper (NewBeanpropertyrowmapper<user> (User.class));Ten         returnReader; One     } A  - @Bean -      PublicItemprocessor<user, string>Processor () { the         return Newuseritemprocessor_db_2_csv (); -     } -  - @Bean +      Publicitemwriter<string> writer ()throwsIOException { -flatfileitemwriter<string> writer =NewFlatfileitemwriter<string>(); +Writer.setresource (NewPathresource ("Test.csv")); ADelimitedlineaggregator<string> Delimitedlineaggregator =NewDelimitedlineaggregator<string>(); atDelimitedlineaggregator.setdelimiter (","); - Writer.setlineaggregator (delimitedlineaggregator); -         returnwriter; -     } -  - @Bean in      PublicJob exportuserjob (jobbuilderfactory jobs, Step s1) { -         returnJobs.get ("Exportuser") to. Incrementer (Newrunidincrementer ()) + . Flow (S1) - . End () the . Build (); *     } $ Panax Notoginseng @Bean -      PublicStep Step1 (stepbuilderfactory stepbuilderfactory, itemreader<user>Reader, theitemwriter<string> writer, Itemprocessor<user, string>processor) { +         returnStepbuilderfactory.get ("Step1") A. <user, string> Chunk (10) the . Reader (reader) + . Processor (processor) - . Writer (writer) $ . Build (); $     } -  - @Bean the      Publicjdbctemplate JdbcTemplate (DataSource DataSource) { -         return NewJdbcTemplate (dataSource);Wuyi     } the  -}

Next, we need to add the handler personitemprocessor_db_2_csv, because we are currently storing the DB database processing in a CSV file, the final form is stored in a string format, so the return value type we are dealing with is set to type string, This will be a lot easier for us to deal with later. Below we will directly post our processing procedures, here, according to the needs of the project, the different filed processing. We're just a demo.

1  Public classUseritemprocessor_db_2_csvImplementsItemprocessor<user, string> {2 3 @Override4      PublicString Process (FinalUser user)throwsException {5         //Db2csv6         FinalString userId = "2014010" +User.getuserid ();7         FinalString gender = User.getgender (). Equals ("M")? " Male ":" Female ";8SimpleDateFormat SDF =NewSimpleDateFormat ("yyyy mm month DD Day");9         FinalString birth =Sdf.format (User.getbirth ());Ten         FinalString userName = User.getusername (). substring (0,1). toUpperCase () +user.getusername (). SUBSTRING (1). toLowerCase (); One         FinalString address= user.getaddress (). substring (0,1). toUpperCase () +user.getaddress (). SUBSTRING (1). toLowerCase (); A         returnUserid+ "," +username+ "," +getaddress+ "," +birth+ "," +gender; -     } -}

The last step, in order to prevent the writing of the file is useless, here I need to remove the schema_all.sql from the previous resources package, or to replace the build table statement, to prevent the data in the database is deleted. It is also necessary to comment out the @configuration and @enablebatchprocessing annotations in the previous configuration file, otherwise the system will be confused with what configuration to start the job.

Db2csv about the learning of spring batch