使用Jakarta POI EXCEL API自动生成ORACLE数据字典的源代码

import java.io.*;
import java.sql.*;
import org.apache.poi.hssf.usermodel.*;

public class AppMain {
    public AppMain() {
    }

    public static void main(String[] args) {
        try {
            HSSFWorkbook wb = new HSSFWorkbook();
            HSSFSheet sheet =null;

           /**连接ORACLE的数据库,关键在于两个系统级的VIEW:
            all_tab_columns 记录着ORACLE所有的字段定义信息.
            DBA_COL_COMMENTS 记录着字段的注释信息,*/

            Class.forName("oracle.jdbc.driver.OracleDriver");
            Connection con = DriverManager.getConnection(
                    "jdbc:oracle:thin:@127.0.0.1:1521:ORACLE", "用户名",   "密码");
            Statement stmt = con.createStatement();
            StringBuffer strbuf = new StringBuffer();
            strbuf.append("SELECT A.*,B.comments");
            strbuf.append(" FROM all_tab_columns A,DBA_COL_COMMENTS B");
            strbuf.append(" WHERE A.owner=B.owner");
            strbuf.append(" AND A.table_name=B.table_name");
            strbuf.append(" AND A.COLUMN_NAME=B.COLUMN_NAME");
            //owner是建立表的用户名
            strbuf.append(" AND A.owner=myuser");
            strbuf.append(" ORDER BY A.TABLE_NAME");
            ResultSet rs = stmt.executeQuery(strbuf.toString());

            String tb = "";
            int k = 0;
            while (rs.next()) {
                  //对每个表生成一个新的sheet,并以表名命名
                if (!tb.equals(rs.getString("TABLE_NAME"))) {
                    sheet = wb.createSheet(rs.getString("TABLE_NAME"));
                    //设置表头的说明
                    HSSFRow row = sheet.createRow(0);
                    setCellGBKValue(row.createCell((short) 0),"字段名");
                    setCellGBKValue(row.createCell((short) 1),"字段类型");
                    setCellGBKValue(row.createCell((short) 2),"字段长度");
                    setCellGBKValue(row.createCell((short) 3),"数字长度");
                    setCellGBKValue(row.createCell((short) 4),"小数位数");
                    setCellGBKValue(row.createCell((short) 5),"能否为NULL");
                    setCellGBKValue(row.createCell((short) 6),"字段说明");
                    k = 1;
                 } else {
                    k++;
                }
                tb = rs.getString("TABLE_NAME");
                HSSFRow row = sheet.createRow(k);
                row.createCell((short) 0).setCellValue(rs.getString(
                        "COLUMN_NAME"));
                row.createCell((short) 1).setCellValue(rs.getString("DATA_TYPE"));
                row.createCell((short) 2).setCellValue(rs.getString(
                        "DATA_LENGTH"));
                row.createCell((short) 3).setCellValue(rs.getString(
                        "DATA_PRECISION"));
                row.createCell((short) 4).setCellValue(rs.getString(
                        "DATA_SCALE"));
                row.createCell((short) 5).setCellValue(rs.getString("NULLABLE"));
                 setCellGBKValue(row.createCell((short) 6),rs.getString("COMMENTS"));

            }

             //把生成的EXCEL文件输出保存
            FileOutputStream fileOut = new FileOutputStream("F:\\数据字典.xls");
            wb.write(fileOut);
            fileOut.close();

            rs.close();
            stmt.close();
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

             /**

                这个函数是为了设置一个CELL为中文字符串

              */

   private static void setCellGBKValue(HSSFCell cell, String value) {
        cell.setCellType(HSSFCell.CELL_TYPE_STRING);
         //设置CELL的编码信息
        cell.setEncoding(HSSFCell.ENCODING_UTF_16);
        cell.setCellValue(value);
    }
}

这样运行这段代码后,就会生成一个数据字典.如果需要,可以对选择的信息做修改,
只需要修改相关的对ORACLE系统表或者视图的SELECT语句即可.