serializer.java

weblogic应用全实例

//声明本类包含在包examples.jdbc.informix4中
package examples.jdbc.informix4;
//声明本类要引入的其他包和类
import java.io.*;
import java.sql.*;
import java.util.Properties;

/**
 * 
 * 这个实例演示怎样插入数据到Informix BLOB 列
 * 它演示这些通过序列化一个对象，并存入到数据库中。
 
 */

public class serializer {
  //主方法
  public static void main(String args[]) {
    //JDBC类
    java.sql.Connection conn         = null;
    java.sql.Statement stmt          = null;
    java.sql.ResultSet rs            = null;
    java.sql.PreparedStatement pstmt = null;
    
    try { 
    	//属性对象
      Properties props = new Properties();
      props.put("user",     "informix");
      props.put("password", "secret");
      props.put("server",   "myDBHost"); 
      props.put("port",     "1493");     
      props.put("db",       "myDB");  
      //加载驱动程序
      Driver myDriver = (Driver) Class.forName("weblogic.jdbc.informix4.Driver").newInstance();
      //建立数据库连接
      conn = myDriver.connect("jdbc:weblogic:informix4", props);
      //创建声明
      stmt = conn.createStatement();
      try {
      	//执行SQL语句，删除表
        stmt.execute("drop table blobtest");
        System.out.println("Dropped table blobtest");
      }
      catch (SQLException e) {
        // 删除的表不存在
      }
      //创建表
      stmt.execute("create table blobtest (foo byte)");
      System.out.println("creating blobtest table");

      // 创建一个要序列化的类实例
      aClass a = new aClass(1234);
      //把对象流转化成一个字节数组
      System.out.println("Created aClass with value 1234");
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      ObjectOutputStream oos = new ObjectOutputStream (baos);
      oos.writeObject(a);
      byte[] aBytes = baos.toByteArray();

      // 把字节数组写到数据表
      pstmt = conn.prepareStatement("insert into blobtest(foo) values (?)");
      pstmt.setBinaryStream(1, new ByteArrayInputStream(aBytes),aBytes.length);
      pstmt.executeUpdate();
      System.out.println("Inserted aClass into the database");
      a = null;
      aBytes = null;

      // 再把写入的对象读出来
      rs = stmt.executeQuery("select foo from blobtest");
      rs.next();
      ObjectInputStream ois = new ObjectInputStream(rs.getBinaryStream(1));
      aClass newa = (aClass)ois.readObject();
      System.out.println("Retrieved the aClass object from the database with value " + newa.getVal());
    } catch (Exception e) {
    	//异常
        System.out.println("Caught Exception: " + e.getMessage());
    } finally {
    	//关闭数据库
        try {
          if (stmt != null)
            stmt.close();
          if (pstmt != null)
            pstmt.close();
          if (rs != null)
            rs.close();
          if (conn != null)
            conn.close();
        } catch (SQLException sqle) {
            System.out.println("SQLExcption was thrown: " + sqle.getMessage());
        }
    }

  }

}
/**
 * 这个类实现接口serializable。用来进行序列化操作

 */ 
class aClass implements Serializable {
  int aValue;
  public aClass(int v) { aValue = v; }
  public int getVal() { return aValue; }
}