通過JDBC的DatabaseMetaData獲取數據庫元數據

1.      在項目src目錄下創建jdbc.properties文件

內容：

dbName=JMJL

className=oracle.jdbc.driver.OracleDriver

url=jdbc:oracle:thin:@168.9.202.49:1521:test

user=TEST

password=TEST

2.      寫一個jdbc處理通用的簡單處理工具類JdbcByPropertiesUtil 

參照《JDBC獲取連接、關閉連接的簡單工具類2》，

地址：http://blog.csdn.net/hu_shengyang/article/details/7861187

3.      下面就是一段獲取數據庫元數據的示例代碼：

package com.adam.test.entity;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import com.adam.dev.utils.JdbcByPropertiesUtil;

public class TestDatabaseMetaData {
    private JdbcByPropertiesUtil jbpu = JdbcByPropertiesUtil.getInstance();

    public JdbcByPropertiesUtil getJbpu() {
        return jbpu;
    }

    public void setJbpu(JdbcByPropertiesUtil jbpu){
        this.jbpu = jbpu;
    }

    public Properties getProperties(){
        Properties pros = JdbcByPropertiesUtil.readPropertiesFile();
        return pros;
    }

    /**
     * 讀取配置文件jdbc.properties中的數據庫名稱
     * @return
     * @throws Exception
     */
    public String getDataSourceName()throws Exception{
        Properties pros = this.getProperties();
        String dbName = pros.get("dbName").toString();
        return dbName;
    }

    /**
     * 獲取數據庫中的表名稱與視圖名稱
     * @return
     */
    public List getTablesAndViews()throws Exception{
        Connection conn = jbpu.getConnection();
        ResultSet rs = null;
        List list = new ArrayList();
        try {
            Properties pros = this.getProperties();
            String schema = pros.get("user").toString();
            DatabaseMetaData metaData = conn.getMetaData();
            rs = metaData.getTables(null, schema, null, new String[]{"TABLE","VIEW"});
            while(rs.next()){
                String tableName = rs.getString("TABLE_NAME");
                list.add(tableName);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally{
            jbpu.close(rs, null, conn);
        }
        return list;
    }

    /**
     * 利用表名和數據庫用戶名查詢出該表對應的字段類型
     * @param tableName 表名
     * @return
     * @throws Exception
     */
    public String generateBean()throws Exception{
        Connection conn = jbpu.getConnection();
        ResultSet rs = null;
        String strJavaBean = "";
        String tableName = this.getDataSourceName();
        try{
            Properties pros = this.getProperties();
            String schema = pros.get("user").toString();
            DatabaseMetaData metaData = conn.getMetaData();
            rs = metaData.getColumns(null, schema, tableName, null);
            Map map = new HashMap();
            while(rs.next()){
                String columnName = rs.getString("COLUMN_NAME");//列名
                String dataType  = rs.getString("DATA_TYPE");//字段數據類型(對應java.sql.Types中的常量)
                String typeName = rs.getString("TYPE_NAME");//字段類型名稱(例如：VACHAR2)
                map.put(columnName, dataType+":"+typeName);
            }

            // 其它生成javaBean的相關操作

        }catch(Exception e){
            e.printStackTrace();
        }finally{
            jbpu.close(rs, null, conn);
        }
        return strJavaBean;
    }

}