• jdbc封装代码



    jdbc封装代码

    
    package jdbcUtil;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import jdbc.RowMap;
    
    public class JdbcUtil {
    	public static Connection getConnection(){
    		Connection connection=null;
    		//加载驱动
    		try {
    			Class.forName("com.mysql.jdbc.Driver");
    			//2创建连接(主机名,端口号,用户名,密码)
    			connection= DriverManager.getConnection("jdbc:mysql://localhost:3306/student", "root", "123456");
    		}
    		 catch (ClassNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		 return connection;
    	
    	}
    
    	public static void close(Connection connection){
    		try {
    			if(connection!=null){
    				connection.close();
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    	}
    
    	public static int executeUpdate(String sql,Object... params){
    		int result=0;
    		Connection connection=getConnection();
    		PreparedStatement pstmt;
    		try {
    			pstmt = connection.prepareStatement(sql);
    			if(params!=null){
    				for(int i=0;i<params.length;i++){
    					pstmt.setObject(i+1, params[i]);
    				}
    			result=pstmt.executeUpdate();
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}finally {
    			close(connection);
    		}
    		return result;
    	}	
    	
    	
    	public static <T>List<T> executeSelect(String sql,RowMap<T> rowMap,Object...params){
    		List<T> result=new ArrayList<>();
    		Connection connection=getConnection();
    		try {
    			PreparedStatement pstmt=connection.prepareStatement(sql);
    			if(params!=null){
    				for(int i=0;i<params.length;i++){
    					pstmt.setObject(i+1, params[i]);
    				}
    			}
    			ResultSet rs=pstmt.executeQuery();
    			while(rs.next()){
    				//将数据行 映射到对象中
    				T t=rowMap.rowMapping(rs);
    				result.add(t);
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}finally {
    			close(connection);
    		}
    		return result;
    	} 
    
    }
    
    


    JdbcUtil.java

    
    package jdbcUtil;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import jdbc.RowMap;
    
    public class JdbcUtil {
    	public static Connection getConnection(){
    		Connection connection=null;
    		//加载驱动
    		try {
    			Class.forName("com.mysql.jdbc.Driver");
    			//2创建连接(主机名,端口号,用户名,密码)
    			connection= DriverManager.getConnection("jdbc:mysql://localhost:3306/student", "root", "123456");
    		}
    		 catch (ClassNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		 return connection;
    	
    	}
    
    	public static void close(Connection connection){
    		try {
    			if(connection!=null){
    				connection.close();
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    	}
    
    	public static int executeUpdate(String sql,Object... params){
    		int result=0;
    		Connection connection=getConnection();
    		PreparedStatement pstmt;
    		try {
    			pstmt = connection.prepareStatement(sql);
    			if(params!=null){
    				for(int i=0;i<params.length;i++){
    					pstmt.setObject(i+1, params[i]);
    				}
    			result=pstmt.executeUpdate();
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}finally {
    			close(connection);
    		}
    		return result;
    	}	
    	
    	
    	public static <T>List<T> executeSelect(String sql,RowMap<T> rowMap,Object...params){
    		List<T> result=new ArrayList<>();
    		Connection connection=getConnection();
    		try {
    			PreparedStatement pstmt=connection.prepareStatement(sql);
    			if(params!=null){
    				for(int i=0;i<params.length;i++){
    					pstmt.setObject(i+1, params[i]);
    				}
    			}
    			ResultSet rs=pstmt.executeQuery();
    			while(rs.next()){
    				//将数据行 映射到对象中
    				T t=rowMap.rowMapping(rs);
    				result.add(t);
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}finally {
    			close(connection);
    		}
    		return result;
    	}
    	
        
    
    }
    
    


    jdbcBean.java

    
    package jdbc;
    
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Scanner;import jdbcUtil.JdbcUtil;class jdbcBean {
    	public static void main(String[] args) {
    		List<Student> list=select();
    		System.out.println(list);
    		/*jdbcBean jdbcBean=new jdbcBean();
    		jdbcBean.tset();*/
    		/*delete();*/
    		/*add();*/
    	}
    	
    	public static int delete(){	
    		return JdbcUtil.executeUpdate("delete from student where sid=? and sname=?", 10,"¹þÊ¿Ææ");
    		
    	}
    	
    	public static int update(){	
    		return JdbcUtil.executeUpdate("update student set sname=?,age=?,sex=? where sid=?","mojie",2,"ÐÛ",1);
    		
    	}
    	
    	public static int add(){
    		return JdbcUtil.executeUpdate("insert into student(sname,age,sex) values(?,?,?)", "ÍÛ¹þ",3,"ÐÛ");
    		
    	}
    	 public static List select(){
    		 
    		 return jdbcUtil.JdbcUtil.executeSelect("select * from student",new RowMap<Student>(){
    			 @Override
    			 public Student rowMapping(ResultSet rs){
    				 Student student=new Student();	
    				try {
    					student.setAge(rs.getInt("age"));
    					student.setName(rs.getString("sname"));
    					student.setSex(rs.getString("sex"));
    					student.setSid(rs.getInt("sid"));
    				} catch (SQLException e) {
    					// TODO Auto-generated catch block
    					e.printStackTrace();
    				}
    				 return student;
    			 }
    		 }, null);
    			/*Connection connection=JdbcUtil.getConnection();
    			List<Student> list=new ArrayList<>();
    			try {
    				PreparedStatement pstmt=connection.prepareStatement("select * from student");
    				ResultSet rs= pstmt.executeQuery();
    				while (rs.next()) {
    					Student student=new Student();	
    					student.setAge(rs.getInt("age"));
    					student.setName(rs.getString("sname"));
    					student.setSex(rs.getString("sex"));
    					student.setSid(rs.getInt("sid"));
    					list.add(student);
    					
    				}
    			} catch (SQLException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}finally {
    				JdbcUtil.close(connection);
    			}
    			return list;*/
    	}
    	 public void tset(){
    		 HashMap<String,Student> sHashMap=new HashMap<>();
    		 for(int i=0;i<4;i++){
    			 System.out.println("qingshuru");
    			 Scanner scanner=new Scanner(System.in);
    			 Integer sid=scanner.nextInt();
    			 String sname=scanner.next();
    			 Integer age=scanner.nextInt();
    			 String sex=scanner.next();
    			 Student student=new Student(sname, age, sid, sex);
    			 sHashMap.put("Student"+i, student);
    		 }
    		 for(int i=0;i<4;i++){
    			 System.out.println(sHashMap.get("Student"+i));
    		 }
    			 
    		
    	 }
    }
    
    


    RowMap.java

    
    package jdbc;
    
    import java.sql.ResultSet;
    
    public interface RowMap<T> {
    	public T rowMapping(ResultSet rs);
    }
    
    


    Student.java

    
    package jdbc;
    
    public class Student {
    	private String name;
    	private int age;
    	private int sid;
    	private String sex;
    	public String getName() {
    		return name;
    	}
    	public Student(String name, int age, int sid, String sex) {
    		super();
    		this.name = name;
    		this.age = age;
    		this.sid = sid;
    		this.sex = sex;
    	}
    	public int getSid() {
    		return sid;
    	}
    	public void setSid(int sid) {
    		this.sid = sid;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public int getAge() {
    		return age;
    	}
    	public void setAge(int age) {
    		this.age = age;
    	}
    	public String getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	@Override
    	public String toString() {
    		return "Student [name=" + name + ", age=" + age + ", sex=" + sex + "]";
    	}
    	public Student(String name, int age, String sex) {
    		super();
    		this.name = name;
    		this.age = age;
    		this.sex = sex;
    	}
    	public Student() {
    		super();
    		// TODO Auto-generated constructor stub
    	}
    	
    	
    }
    
    
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  • 原文地址:https://www.cnblogs.com/qixidi/p/10221719.html
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