经过长时间的学习后今天又回来练练手,觉得记下来挺好,就针对mysql数据库(其他数据库亦同)写下java连接数据库的一个例子,仅供参考……
此文是针对java连接数据库的第二个类型——用。properities属性文件连接。
首先你得在mysql数据库里新建数据库如:test,再添加数据;
其次,在new file文件名为**.properities如:DbConfig.properities,内容如下:
driver = com.mysql.jdbc.Driver
url = jdbc:mysql://127.0.0.1:3306/test
user = root
password = 1234
再次,别忘记导入mysql-connector-java-5.1.7-bin.jar包;新建项目后直接上代码,代码可以说明一切的。
进入正题,直接上代码:
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class JdbcPropritiesConnection {
private final static String filePath = "src/DbConfig.properities";
public static Connection getConn() {
InputStream ins = null;
Connection conn = null;
String driver = "";
String url = "";
String user = "";
String password = "";
Properties props = new Properties();
try {
ins = new FileInputStream(filePath);
props.load(ins);
driver = props.getProperty("driver");
url = props.getProperty("url");
user = props.getProperty("user");
password = props.getProperty("password");
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
if (!conn.isClosed()) System.out.println("mysql 连接成功。。。。");
} catch (Exception e) {
e.printStackTrace();
System.out.println("出错了。。。mysql 连接失败。。。。");
}finally{
if(ins!=null)
try {
ins.close();
} catch (Exception e) {
e.printStackTrace();
}
}
return conn;
}
public static void main(String[] args) {
Connection con = null;
ResultSet rs= null;
Statement stmt = null;
try {
con = getConn();
stmt = con.createStatement();
String sql = "select * from user";
rs = stmt.executeQuery(sql);
while(rs.next()){
String userId = rs.getString("userID");
String username = rs.getString("username");
String age = rs.getString("age");
String sex = rs.getString("sex");
System.out.println("useID="+userId+" username="+username+" age="+age+" sex="+sex);
}
rs.close();
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
结果如下:
成功了……