getrecordsfromdb.java

一个简单的数据库同步系统

package com.unimas.dbsync.input;


import com.unimas.dbsync.entity.SourceTabBaseBean;

import java.sql.*;
import java.io.IOException;

/**
 * Created by IntelliJ IDEA.
 * User: 孔加亮
 * Date: 2008-12-8
 * Time: 15:11:40
 */

/**
 * 从数据库中读取源端表的记录.
 */
public class GetRecordsFromDb {
    private int ColumnCount;
    private String ServerTabName;//用于插入表名（从配置文件获取*）
    private String TabFieldInf = "";
    private String RecordsInf = "";
    private int RecordsNum = 0;

    /**
     * @param bean 对象bean表示源端表信息
     */
    public void getStuInf(SourceTabBaseBean bean) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet resultSet = null;

        try {
            conn = SourceDataBase.getInstance().getConnection();//建立与数据库的连接
            stmt = conn.createStatement();
            resultSet = stmt.executeQuery("select * from student"); //得到表信息(*应该由列名代替)

            //表字段信息应从配置文件中读取（需改）
            if (!resultSet.wasNull()) {
                ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
                //获取表的基本信息
                System.out.println("表字段个数:" + resultSetMetaData.getColumnCount());
                ColumnCount = resultSetMetaData.getColumnCount(); // 得到表字段个数
                bean.setColumnCount(ColumnCount);
                System.out.println("表字段信息");
                for (int i = 1; i <= ColumnCount; i++) {
                    if (i != ColumnCount) {
                        System.out.println(resultSetMetaData.getColumnName(i) +
                                "(" + resultSetMetaData.getColumnTypeName(i) +
                                "[" + resultSetMetaData.getColumnDisplaySize(i) +
                                "]" + ")");
                        TabFieldInf += resultSetMetaData.getColumnName(i) +
                                "(" + resultSetMetaData.getColumnTypeName(i) +
                                "[" + resultSetMetaData.getColumnDisplaySize(i) +
                                "]" + ")" + "\r\n";
                    } else {
                        System.out.println(resultSetMetaData.getColumnName(i) +
                                "(" + resultSetMetaData.getColumnTypeName(i) +
                                "[" + resultSetMetaData.getColumnDisplaySize(i) +
                                "]" + ")");
                        TabFieldInf += resultSetMetaData.getColumnName(i) +
                                "(" + resultSetMetaData.getColumnTypeName(i) +
                                "[" + resultSetMetaData.getColumnDisplaySize(i) +
                                "]" + ")" + "\r\n\r\n";

                    }
                }
                bean.setFieldName(TabFieldInf);  //将表字段信息存入对象
            }
            if (!resultSet.wasNull()) {
                RecordsNum++;
            }
            //获取服务端中的表的详细信息
            while (resultSet.next()) {
                for (int i = 1; i <= ColumnCount; i++) {
                    if (i != ColumnCount) {
                        RecordsInf += resultSet.getObject(i).toString() + "\r\n";
                    } else {
                        RecordsInf += resultSet.getObject(i).toString() + "\r\n\r\n";
                    }
                }
            }
            bean.setRecordsNum(RecordsNum);
            bean.setTabRecords(RecordsInf);
            bean.setRecordsNum(RecordsNum);
            //异常处理
        } catch (SQLException sqle) {
            System.out.println("未能正常从服务端数据库中获取信息");

        } catch (ClassNotFoundException e) {
            System.out.println("未能与服务端数据库正常通信");
        }
        finally {
            if (resultSet != null) {
                try {
                    resultSet.close();
                } catch (SQLException sqlE) {
                    sqlE.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlE) {
                    sqlE.printStackTrace();
                }
            }
            SourceDataBase.getInstance().closeConnection(conn);
        }

    }
}