Admin: 1 версия

2010-06-01T06:34:11Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:44Z

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== Cached RS ==



<source lang="java">

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import javax.sql.rowset.CachedRowSet;
public class CachedRS {
private final static String CRS_FILE_LOC = "cachedrs.crs";
public static void main(String[] args) throws Exception {
FileInputStream fis = new FileInputStream(CRS_FILE_LOC);
ObjectInputStream in = new ObjectInputStream(fis);
CachedRowSet crs = (CachedRowSet) in.readObject();
fis.close();
in.close();

Class.forName("oracle.jdbc.driver.OracleDriver");
crs.setUrl("jdbc:oracle:thin:@localhost:1521:ORCL");
crs.setUsername("yourName");
crs.setPassword("mypwd");
String sql = "SELECT SSN, Name, Salary, Hiredate FROM Employees WHERE SSN=?";
crs.setCommand(sql);
crs.setInt(1, 111111111);
crs.execute();
FileOutputStream fos = new FileOutputStream(CRS_FILE_LOC);
ObjectOutputStream out = new ObjectOutputStream(fos);
out.writeObject(crs);
out.close();
crs.close();

fis = new FileInputStream(CRS_FILE_LOC);
in = new ObjectInputStream(fis);
crs = (CachedRowSet) in.readObject();
fis.close();
in.close();
while (crs.next()) {
System.out.print("SSN: " + crs.getInt("ssn"));
System.out.print(", Name: " + crs.getString("name"));
System.out.print(", Salary: $" + crs.getDouble("salary"));
System.out.print(", HireDate: " + crs.getDate("hiredate"));
}
crs.close();
}
}
</source>



== Save CachedRowSet Back To Database ==



<source lang="java">

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.Types;
import javax.sql.RowSetMetaData;
import javax.sql.rowset.CachedRowSet;
import javax.sql.rowset.RowSetMetaDataImpl;
import com.sun.rowset.CachedRowSetImpl;
public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getHSQLConnection();
System.out.println("Got Connection.");
Statement st = conn.createStatement();
st.executeUpdate("create table survey (id int,name varchar);");
st.executeUpdate("create view surveyView as (select * from survey);");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st.executeUpdate("insert into survey (id,name ) values (2,"anotherValue")");

CachedRowSet crs = null;
RowSetMetaData rsMD = new RowSetMetaDataImpl();
rsMD.setColumnCount(2);
rsMD.setColumnName(1, "id");
rsMD.setColumnType(1, Types.VARCHAR);
rsMD.setColumnName(2, "name");
rsMD.setColumnType(2, Types.VARCHAR);
// sets the designated column"s table name, if any, to the given String.
rsMD.setTableName(1, "survey");
rsMD.setTableName(2, "survey");
// use a custom made RowSetMetaData object for CachedRowSet object
crs = new CachedRowSetImpl();
crs.setMetaData(rsMD);
crs.moveToInsertRow();
crs.updateString(1, "1111");
crs.updateString(2, "alex");
crs.insertRow();
crs.moveToInsertRow();
crs.updateString(1, "2222");
crs.updateString(2, "jane");
crs.insertRow();
// if you want to commit changes from a CachedRowSet
// object to your desired datasource, then you must
// create a Connection object.
//
//conn = getHSQLConnection();
// moves the cursor to the remembered cursor position, usually
// the current row. This method has no effect if the cursor is
// not on the insert row.
crs.moveToCurrentRow();
// when the method acceptChanges() is executed, the CachedRowSet
// object"s writer, a RowSetWriterImpl object, is called behind the
// scenes to write the changes made to the rowset to the underlying
// data source. The writer is implemented to make a connection to
// the data source and write updates to it.
crs.acceptChanges(conn);
conn.close();
}
private static Connection getHSQLConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
String url = "jdbc:hsqldb:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
public static Connection getMySqlConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/demo2s";
String username = "oost";
String password = "oost";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public static Connection getOracleConnection() throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:caspian";
String username = "mp";
String password = "mp2";
Class.forName(driver); // load Oracle driver
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
}

</source>

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Admin: 1 версия

в 18:01, 31 мая 2010