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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
}
}
