JDBC例子

package dao;

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

public class BaseDao {
	
	//连接数据库的方法
	public Connection getConn() throws Exception{
		Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		String url="jdbc:sqlserver://localhost:1433;"
			+ "DatabaseName=scmng";
		String user="sa";
		String password="yuyu668668";
		return DriverManager.getConnection(url, user, password);
	}
	
	//关闭数据库的方法
	public void closeAll(Connection conn,Statement stmt,ResultSet rs){
		
		if(rs!=null){
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(stmt!=null){
			try {
				stmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(conn!=null){
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}

package entity;

public class Student {
	private String id;
	private String sno;
	private String name;
	private String gender;

	public Student() {
		super();
	}

	public Student(String sno, String name, String gender) {
		super();
		this.sno = sno;
		this.name = name;
		this.gender = gender;
	}

	public Student(String id, String sno, String name, String gender) {
		super();
		this.id = id;
		this.sno = sno;
		this.name = name;
		this.gender = gender;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getSno() {
		return sno;
	}

	public void setSno(String sno) {
		this.sno = sno;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getGender() {
		return gender;
	}

	public void setGender(String gender) {
		this.gender = gender;
	}
}

package dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import entity.Student;

public class StudentDao extends BaseDao{
	
	//查询所有的方法
	public List<Student> findAll(){
		
		List<Student> list=new ArrayList<Student>();
		String sql="select * from student";
		Student stu=null;
		
		Connection conn=null;
		Statement stmt=null;
		ResultSet rs=null;
		
		try {
			conn=this.getConn();
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);
			
			while(rs.next()){
				stu=new Student(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4));
				list.add(stu);
			}
			
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			this.closeAll(conn, stmt, rs);
		}
		
		return list;
	}
}

package test;

import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import com.mysql.jdbc.Connection;

public class TestJDBC {
	public static void main(String[] args) throws Exception {
		//1.加载驱动包
		Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		System.out.println("驱动加载成功！");
		
		//2.连接数据库
		String url="jdbc:sqlserver://localhost:1433;"
			+ "DatabaseName=scmng";
		String user="sa";
		String psd="yuyu668668";
		java.sql.Connection conn=DriverManager.getConnection(url, user, psd);
		System.out.println("数据库连接成功！");
		
		//3.语句
		String sql="select * from student";
		Statement stmt=conn.createStatement();
		System.out.println("语句获取成功");
		
		//4.结果集
		ResultSet rs=stmt.executeQuery(sql);
		System.out.println("执行查询成功！");
		
		//5.处理结果集,使用循环处理
		//rs.next()指针乡下移动一条语句，如果到达最后一条后面，则结果为FALSE，循环结束
		while(rs.next()){
			System.out.println(rs.getString(1)+"\t"+rs.getString(2)+"\t"+
		rs.getString(3)+"\t"+rs.getString(4));
		}
		
		//6.关闭结果集
		rs.close();
		//7.关闭语句
		stmt.close();
		//8.关闭连接
		conn.close();
	
	}
}