用xml配置连接数据库

实现功能：

           1，在XML文件里配置数据库连接（能修改数据库连接相关参数，如用户名等）

           2，同时配置两个数据库连接

           3，除连接数数据库参数外，其他参数的传送

参考资料：

xml 数据库连接信息 配置与读取(dom4j) - hzh的日志 - 网易博客
http://blog.163.com/woshihezhonghua@126/blog/static/1271436362010510253725/

具体代码：

1，sys-config.xml

需要的jar包：sqljdbc4.jar，ojdbc14.jar

      
	  
        oracle.jdbc.driver.OracleDriver
        jdbc:oracle:thin:@111.111.1.11:1521/orcl
        201
        300
        006
        10
        10
        6
        10
     
    
     
        com.microsoft.sqlserver.jdbc.SQLServerDriver
        jdbc:sqlserver://222.222.0.222:1433;DatabaseName=1111
        b
        b
     
  

2，将要传递的参数实例化

OrclJdbcInfo.java

package utils;

public class OrclJdbcInfo {
	
	    private String orcldriverName;
	    private String orclurl;
	    private String orclusername;
	    private String orclpassword;
	    private String orcldays;
	    private String orclmandt;
	    private String orclpasesize;
	    private String orclrefreshTime;
	    private String orclpageRefresh;


		// 注解，能在编译期间发现错误
	    @Override
	    public String toString() 
	      {
	        // TODO Auto-generated method stub
	        return this.getClass().getName() + "{orcldriverName=" + this.orcldriverName
	                + ",orclurl=" + this.orclurl + ",orclusername=" + this.orclusername
	                + ",orclpassword=" + this.orclpassword + ",orcldays="+this.orcldays
	                +",orclmandt="+this.orclmandt+",orclpagesize="+this.orclpasesize
	                +",orclrefreshtime="+this.orclrefreshTime+",orclpageRefresh="+this.orclpageRefresh+"}";
	        
	      }
	    
		public String getOrclrefreshTime() {
			return orclrefreshTime;
		}

		public void setOrclrefreshTime(String orclrefreshTime) {
			this.orclrefreshTime = orclrefreshTime;
		}


		public String getOrclpageRefresh() {
			return orclpageRefresh;
		}

		public void setOrclpageRefresh(String orclpageRefresh) {
			this.orclpageRefresh = orclpageRefresh;
		}
 

		public String getOrclpasesize() {
			return orclpasesize;
		}
		public void setOrclpasesize(String orclpasesize) {
			this.orclpasesize = orclpasesize;
		}
		public String getOrcldriverName() {
			return orcldriverName;
		}
		public void setOrcldriverName(String orcldriverName) {
			this.orcldriverName = orcldriverName;
		}
		public String getOrclurl() {
			return orclurl;
		}
		public void setOrclurl(String orclurl) {
			this.orclurl = orclurl;
		}
		public String getOrclusername() {
			return orclusername;
		}
		public void setOrclusername(String orclusername) {
			this.orclusername = orclusername;
		}
		public String getOrclpassword() {
			return orclpassword;
		}
		public void setOrclpassword(String orclpassword) {
			this.orclpassword = orclpassword;
		}
	    public String getOrcldays() {
			return orcldays;
		}
		public void setOrcldays(String orcldays) {
			this.orcldays = orcldays;
		}
		public String getOrclmandt() {
			return orclmandt;
		}
		public void setOrclmandt(String orclmandt) {
			this.orclmandt = orclmandt;
		}

}

JdbcInfo.java

package utils;

public class JdbcInfo {
	    private String driverName;
	    private String url;
	    private String username;
	    private String password;

	    // 注解，能在编译期间发现错误
	    @Override
	    public String toString() {
	        // TODO Auto-generated method stub
	        return this.getClass().getName() + "{driverName=" + this.driverName
	                + ",url=" + this.url + ",username=" + this.username
	                + ",password=" + this.password + "}";
	    }

	    public String getDriverName() {
	        return driverName;
	    }

	    public void setDriverName(String driverName) {
	        this.driverName = driverName;
	    }

	    public String getUrl() {
	        return url;
	    }

	    public void setUrl(String url) {
	        this.url = url;
	    }

	    public String getUsername() {
	        return username;
	    }

	    public void setUsername(String username) {
	        this.username = username;
	    }

	    public String getPassword() {
	        return password;
	    }

	    public void setPassword(String password) {
	        this.password = password;
	    }
}

3，解析XML

ConfigReader.java

需要的jar包：dom4j-1.6.1.jar

package utils;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;


/*
 * 讀取xml配置文件sys-config.xml
 * 採用單例模式
 */
public class ConfigReader {
    private static ConfigReader instance = new ConfigReader();
    private Document doc;
    private JdbcInfo jdbcInfo;
    private OrclJdbcInfo orclJdbcInfo;
    private ConfigReader() {
        try {
             doc = new SAXReader().read(Thread.currentThread() .getContextClassLoader().getResourceAsStream("sys-config.xml"));
   
                 jdbcInfo = new JdbcInfo();
                 orclJdbcInfo = new OrclJdbcInfo();
                 
                Element driverNameElt = (Element)doc.selectObject("/config/db-info/driver-name");
                Element urlElt = (Element)doc.selectObject("/config/db-info/url");
                Element usernameElt = (Element)doc.selectObject("/config/db-info/username");
                Element passwordElt = (Element)doc.selectObject("/config/db-info/password");
                
                jdbcInfo.setDriverName(driverNameElt.getStringValue());
                jdbcInfo.setUrl(urlElt.getStringValue());
                jdbcInfo.setUsername(usernameElt.getStringValue());
                jdbcInfo.setPassword(passwordElt.getStringValue());
                
                Element orcldriverNameElt = (Element)doc.selectObject("/config/db-info/orcldriver-name");
                Element orclurlElt = (Element)doc.selectObject("/config/db-info/orclurl");
                Element orclusernameElt = (Element)doc.selectObject("/config/db-info/orclusername");
                Element orclpasswordElt = (Element)doc.selectObject("/config/db-info/orclpassword");
                Element orcldaysElt = (Element)doc.selectObject("/config/db-info/orcldays");
                Element orclmandtElt = (Element)doc.selectObject("/config/db-info/orclmandt");
                Element orclpasesizeElt = (Element)doc.selectObject("/config/db-info/orclpasesize");
                Element orclrefreshTimeElt = (Element)doc.selectObject("/config/db-info/orclrefreshTime");
                Element orclpageRefreshElt = (Element)doc.selectObject("/config/db-info/orclpageRefresh");
                
                
                orclJdbcInfo.setOrcldriverName(orcldriverNameElt.getStringValue());
                orclJdbcInfo.setOrclurl(orclurlElt.getStringValue());
                orclJdbcInfo.setOrclusername(orclusernameElt.getStringValue());
                orclJdbcInfo.setOrclpassword(orclpasswordElt.getStringValue());
                orclJdbcInfo.setOrcldays(orcldaysElt.getStringValue());
                orclJdbcInfo.setOrclmandt(orclmandtElt.getStringValue());
                orclJdbcInfo.setOrclpasesize(orclpasesizeElt.getStringValue());
                orclJdbcInfo.setOrclrefreshTime(orclrefreshTimeElt.getStringValue());
                orclJdbcInfo.setOrclpageRefresh(orclpageRefreshElt.getStringValue());
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public static ConfigReader getInstance() {
        return instance;
    }
    
    public JdbcInfo getjdbcInfo(){
        return jdbcInfo;
    }
    
    public OrclJdbcInfo getorclJdbcInfo(){
        return orclJdbcInfo;
    }
   
    //用於測試是否成功讀取數據
   public static void main(String[] args) {
      System.out.println(ConfigReader.getInstance().getjdbcInfo());
      System.out.println(ConfigReader.getInstance().getorclJdbcInfo());
  }
}

4，实现类

DBUtil.java

package utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServlet;

import entity.Sap;

/**
 * 数据库工具类
 * 
 * @author Administrator
 * 
 */
public class DBUtil extends HttpServlet{

    /**
     * 取得数据库连接
     * 
     * @return
     */
//map方法封装值
    public static Map getConnection() {
    	Map map = new HashMap() ; 
    	Connection orclConn = null;
    	Connection conn = null;
        try {
            JdbcInfo jdbcInfo = ConfigReader.getInstance().getjdbcInfo();
            Class.forName(jdbcInfo.getDriverName());
            conn = DriverManager.getConnection(jdbcInfo.getUrl(), jdbcInfo.getUsername(), jdbcInfo.getPassword());
            
            OrclJdbcInfo orclJdbcInfo = ConfigReader.getInstance().getorclJdbcInfo();
            Class.forName(orclJdbcInfo.getOrcldriverName());
            orclConn = DriverManager.getConnection(orclJdbcInfo.getOrclurl(), orclJdbcInfo.getOrclusername(), orclJdbcInfo.getOrclpassword());
            
            map.put("orcldays",orclJdbcInfo.getOrcldays()); 
            map.put("orclmandt",orclJdbcInfo.getOrclmandt());
            map.put("orclpasesize",orclJdbcInfo.getOrclpasesize());
            map.put("orclrefreshTime",orclJdbcInfo.getOrclrefreshTime());
            map.put("orclpageRefresh",orclJdbcInfo.getOrclpageRefresh());
            
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
  
        map.put("orclConn", orclConn);
        map.put("conn", conn);
        
    	return map;

    }

    public static void close(PreparedStatement pstmt) {
        if (pstmt != null) {
            try {
                pstmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void close(Statement stmt) {
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close(Connection conn) {
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close(ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void commit(Connection conn) {
        if (conn != null) {
            try {
                conn.commit();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void rollback(Connection conn) {
        if (conn != null) {
            try {
                conn.rollback();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void setAutoCommit(Connection conn, boolean autoCommit) {
        if (conn != null) {
            try {
                conn.setAutoCommit(autoCommit);
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }


    //测试是否连接成功
    public static void main(String[] args) {
        DBUtil.getConnection();
        System.out.println("---------ok---------");
    }
}