通过JDBC的DatabaseMetaData获取数据库元数据

1.      在项目src目录下创建jdbc.properties文件

内容：

dbName=JMJL

className=oracle.jdbc.driver.OracleDriver

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

user=TEST

password=TEST

2.      写一个jdbc处理通用的简单处理工具类JdbcByPropertiesUtil 

参照《JDBC获取连接、关闭连接的简单工具类2》，

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

3.      下面就是一段获取数据库元数据的示例代码：

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;}/** * 读取配置文件jdbc.properties中的数据库名称 * @return * @throws Exception */public String getDataSourceName()throws Exception{Properties pros = this.getProperties();String dbName = pros.get("dbName").toString();return dbName;}/** * 获取数据库中的表名称与视图名称 * @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;}/** * 利用表名和数据库用户名查询出该表对应的字段类型 * @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");//字段数据类型(对应java.sql.Types中的常量)String typeName = rs.getString("TYPE_NAME");//字段类型名称(例如：VACHAR2)map.put(columnName, dataType+":"+typeName);}// 其它生成javaBean的相关操作}catch(Exception e){e.printStackTrace();}finally{jbpu.close(rs, null, conn);}return strJavaBean;}}

这只是一些简单常用的jdbc元数据的获取方式，如果需要更加深入请参考java api。