JDBC 连接数据库

1. 配置文件

# 
db.type            = oracle
# 
# Oracle
# jar: ojdbc6.jar
# dir: %ORACLE_HOME%/jdbc/lib
# url: http://www.oracle.com/technetwork/database/features/jdbc/index-091264.html
oracle.driver      = oracle.jdbc.driver.OracleDriver
oracle.url         = jdbc:oracle:thin:@//192.168.1.27:1521/orcl
oracle.user        = sys
oracle.password    = 1234567a?
oracle.props       = internal_logon:sysdba
# 
# DB2
# jar: db2jcc4.jar
# dir: %DB2_HOME%/SQLLIB/java
# url: http://www-01.ibm.com/support/docview.wss?uid=swg21363866
db2.driver         = com.ibm.db2.jcc.DB2Driver
db2.url            = jdbc:db2://192.168.1.27:50000/sample
db2.user           = db2admin
db2.password       = 123456a?
# 
# Sql Server
# jar: sqljdbc4.jar
# url: http://www.microsoft.com/zh-CN/download/details.aspx?displaylang=en&id=11774
sqlserver.driver   = com.microsoft.sqlserver.jdbc.SQLServerDriver
sqlserver.url      = jdbc:sqlserver://192.168.1.27:1433;databaseName=MyTest
sqlserver.user     = user1
sqlserver.password = pass1
# 
# MySql
# jar: mysql-connector-java-5.1.26-bin.jar
# url: http://dev.mysql.com/downloads/connector/j/#downloads
mysql.driver       = com.mysql.jdbc.Driver
mysql.url          = jdbc:mysql://192.168.1.27:3306/dastest
mysql.user         = root
mysql.password     = 123456a?
mysql.props        = useUnicode:yes,characterEncoding:utf8,autoReconnect:true,failOverReadOnly:false
# 
# End

2. Java Code

import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		
		String propFile = Main.class.getResource("jdbc.properties").getFile();
		Properties props = loadJdbcProps(propFile);
		
		// 
		Class.forName(props.getProperty("driver"));
		Connection conn = DriverManager.getConnection(props.getProperty("url"), props);
		DatabaseMetaData dbmd = conn.getMetaData();
		System.out.println("ProductName    = " + dbmd.getDatabaseProductName());
		System.out.println("ProductVersion = " + dbmd.getDatabaseProductVersion());
		conn.close();
	}
    
	/**
	 * load jdbc.properties
	 * @param propFile
	 * @return
	 * @throws IOException
	 */
	@SuppressWarnings("unchecked")
	public static Properties loadJdbcProps(String propFile) throws IOException {
		Properties jdbcProps = new Properties();
		
		FileInputStream fin = null;
		try {
			fin = new FileInputStream(propFile);
			Properties allProps = new Properties();
			allProps.load(fin);
			String dbType = allProps.getProperty("db.type");
			String others = allProps.getProperty(dbType + ".props");
			int prefixLength = dbType.length() + 1;
			
			Iterator<Entry<String, String>> it = (Iterator)allProps.entrySet().iterator();
			while (it.hasNext()) {
				Entry<String, String> entry = it.next();
				String key = entry.getKey();
				if (key.startsWith(dbType)) {
					jdbcProps.setProperty(key.substring(prefixLength), entry.getValue());
				}
				it.remove();
			}
			
			jdbcProps.putAll(toMap(others));
		} 
		finally {
			try { if (fin != null) { fin.close(); } } catch (Exception e) {}
		}
		
		return jdbcProps;
	}
	
	/**
	 * key1:value1,key2:value2 -> map
	 * @param str
	 * @return
	 */
	private static Map<String, String> toMap(String str) {
		Map<String, String> map = new HashMap<String, String>();
		if (str == null) {
			return map;
		}
		
		Pattern p = Pattern.compile("(\\w+):(\\w+),?");
		Matcher m = p.matcher(str);
		while (m.find()) {
			map.put(m.group(1), m.group(2));
		}
		return map;
	}
}