Java_DBUtil


/**
*DBUtil.java
*连接数据库
*/
import java.io.*;
import java.sql.*;
import java.util.Properties;
public class Db {
private String driver;//定义驱动
private String url;//定义URL
private String user;//定义用户名
private String password;//定义密码
private Connection conn;//定义连接
private Statement stmt;//定义STMT
private ResultSet rs;//定义结果集
//构造函数,默认加裁配置文件为jdbc.driver
public Db(){
this("jdbc.properties");
}
//有参构造函数,传入路径Conf并用方法loadProperties进行加载,用setConn进行设置
public Db(String conf) {
loadProperties(conf);
setConn();
}
//返回Conn
public Connection getConn(){
return this.conn;
}
//传入参数路径Conf加载配置文件取得配置文件中的参数并设置为类变量的参数
private void loadProperties(String conf){
Properties props = new Properties();
try {
props.load(new FileInputStream(conf));//根据配置文件路径Conf加载配置文件
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
this.driver = props.getProperty("driver");//从配置文件中取得相应的参数并设置类变量
this.url = props.getProperty("url");
this.user = props.getProperty("username");
this.password = props.getProperty("password");
}
//implement the Connection
//设置CONN
private void setConn(){
try {
Class.forName(driver);
this.conn = DriverManager.getConnection(url,user,password);
} catch(ClassNotFoundException classnotfoundexception) {
classnotfoundexception.printStackTrace();
System.err.println("db: " + classnotfoundexception.getMessage());
} catch(SQLException sqlexception) {
System.err.println("db.getconn(): " + sqlexception.getMessage());
}
}
//执行插入
public void doInsert(String sql) {
try {
Statement statement = conn.createStatement();
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeInset:" + sqlexception.getMessage());
}finally{

}
}
//执行删除
public void doDelete(String sql) {
try {
stmt = conn.createStatement();
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeDelete:" + sqlexception.getMessage());
}
}
//执行更新
public void doUpdate(String sql) {
try {
stmt = conn.createStatement();
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeUpdate:" + sqlexception.getMessage());
}
}
//查询结果集
public ResultSet doSelect(String sql) {
try {
stmt = conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeQuery: " + sqlexception.getMessage());
}
return rs;
}
/**
*关闭数据库结果集,数据库操作对象,数据库链接
@Function: Close all the statement and conn int this instance and close the parameter ResultSet
@Param: ResultSet
@Exception: SQLException,Exception
**/
public void close(ResultSet rs) throws SQLException, Exception {

if (rs != null) {
rs.close();
rs = null;
}

if (stmt != null) {
stmt.close();
stmt = null;
}

if (conn != null) {
conn.close();
conn = null;
}
}

/**
*关闭数据库操作对象,数据库连接对象
* Close all the statement and conn int this instance
* @throws SQLException
* @throws Exception
*/
public void close() throws SQLException, Exception {
if (stmt != null) {
stmt.close();
stmt = null;
}

if (conn != null) {
conn.close();
conn = null;
}
}
//测试类
public static void main(String[] args){
try{
//根据传入配置路径构造类
Db db = new Db("src\\com\\struts\\properties\\jdbc.properties");
// db.loadProperties("src\\com\\struts\\properties\\jdbc.properties");
// System.out.print(db.driver);
//取得连接
Connection conn = db.getConn();
if(conn != null && !conn.isClosed()) {
System.out.println("連結成功");
ResultSet rs = db.doSelect("select * from usertable");
while(rs.next()){
System.out.println(rs.getString(1)+":"+rs.getString(2)+":"+rs.getString(3));
}
rs.close();
conn.close();
}
}catch(SQLException e) {
e.printStackTrace();
}
}
}





//配置文件jdbc.properties
driver=com.microsoft.jdbc.sqlserver.SQLServerDriver
url=jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=qtliu
username=sa
password=sa




MySQL:
String Driver="com.mysql.jdbc.Driver"; //驱动程序
String URL="jdbc:mysql://localhost:3306/db_name"; //连接的URL,db_name为数据库名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).new Instance();
Connection con=DriverManager.getConnection(URL,Username,Password);
Microsoft SQL Server 2.0驱动(3个jar的那个):
String Driver="com.microsoft.jdbc.sqlserver.SQLServerDriver"; //连接SQL数据库的方法
String URL="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=db_name"; //db_name为数据库名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).new Instance(); //加载数据可驱动
Connection con=DriverManager.getConnection(URL,UserName,Password); //
Microsoft SQL Server 3.0驱动(1个jar的那个): // 老紫竹完善
String Driver="com.microsoft.sqlserver.jdbc.SQLServerDriver"; //连接SQL数据库的方法
String URL="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=db_name"; //db_name为数据库名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).new Instance(); //加载数据可驱动
Connection con=DriverManager.getConnection(URL,UserName,Password); //
Sysbase:
String Driver="com.sybase.jdbc.SybDriver"; //驱动程序
String URL="jdbc:Sysbase://localhost:5007/db_name"; //db_name为数据可名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance();
Connection con=DriverManager.getConnection(URL,Username,Password);
Oracle(用thin模式):
String Driver="oracle.jdbc.driver.OracleDriver"; //连接数据库的方法
String URL="jdbc:oracle:thin:@loaclhost:1521:orcl"; //orcl为数据库的SID
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance(); //加载数据库驱动
Connection con=DriverManager.getConnection(URL,Username,Password);
PostgreSQL:
String Driver="org.postgresql.Driver"; //连接数据库的方法
String URL="jdbc:postgresql://localhost/db_name"; //db_name为数据可名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance();
Connection con=DriverManager.getConnection(URL,Username,Password);
DB2:
String Driver="com.ibm.db2.jdbc.app.DB2.Driver"; //连接具有DB2客户端的Provider实例
//String Driver="com.ibm.db2.jdbc.net.DB2.Driver"; //连接不具有DB2客户端的Provider实例
String URL="jdbc:db2://localhost:5000/db_name"; //db_name为数据可名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance();
Connection con=DriverManager.getConnection(URL,Username,Password);
Informix:
String Driver="com.informix.jdbc.IfxDriver";
String URL="jdbc:Informix-sqli://localhost:1533/db_name:INFORMIXSER=myserver"; //db_name为数据可名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance();
Connection con=DriverManager.getConnection(URL,Username,Password);
JDBC-ODBC:
String Driver="sun.jdbc.odbc.JdbcOdbcDriver";
String URL="jdbc:odbc:dbsource"; //dbsource为数据源名
String Username="username"; //用户名
String Password="password"; //密码
Class.forName(Driver).newInstance();
Connection con=DriverManager.getConnection(URL,Username,Password);



package utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBConnection {

static Connection conn=null;
static PreparedStatement ps=null;
static ResultSet rs=null;

static{
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");

} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

//静态方式取得链接
public static Connection getConn(){
String uname="sa";
String passwd="";
String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=qtliu";
try {
conn=DriverManager.getConnection(url,uname,passwd);
System.out.println("GetConnection success");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}


//释放资源
public static void release(){

if(rs!=null){
try {
rs.close();
System.out.println("rs Closed!");
} catch (SQLException e) {
e.printStackTrace();
}
}
if(ps!=null){
try {
ps.close();
System.out.println("ps Closed!");
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
System.out.println("conn Closed!");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}




=====================
package utils;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class TestGetConn {

/**
* @param args
*/
public static void main(String[] args) {
Connection conn=DBConnection.getConn();
try {
Statement st=conn.createStatement();
String find="select *from qt";
ResultSet rs=st.executeQuery(find);
while(rs.next()){
System.out.println("name:"+rs.getString(2)+"\n");
System.out.println("passwd:"+rs.getString(3));
}
System.out.println();
DBConnection.release();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}


}

}
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