1.DAO层
dao层处理增删改查
AccountDao
package cn.itcast.dbutils.demo;
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import cn.itcast.domain.Account;
import cn.itcast.utils.JdbcUtils;
public class AccountDao {
public AccountDao() {
super();
// TODO Auto-generated constructor stub
}
private Connection conn;
public AccountDao(Connection conn){
this.conn = conn;
}
public void update(Account a){
try{
QueryRunner runner = new QueryRunner();
String sql = "update account set money=? where id=?";
Object params[] = {a.getMoney(),a.getId()};
runner.update(JdbcUtils.getConnection(),sql, params);
}catch (Exception e) {
throw new RuntimeException(e);
}
}
public Account find(int id){
try{
QueryRunner runner = new QueryRunner();
String sql = "select * from account where id=?";
return (Account) runner.query(JdbcUtils.getConnection(),sql, id, new BeanHandler(Account.class));
}catch (Exception e) {
throw new RuntimeException(e);
}
}
//从a--->b帐户转100元
public void transfer() throws SQLException{
Connection conn = null;
try{
conn = JdbcUtils.getConnection();
conn.setAutoCommit(false);
QueryRunner runner = new QueryRunner();
String sql1 = "update account set money=money-100 where name='aaa'";
runner.update(conn,sql1);
String sql2 = "update account set money=money+100 where name='bbb'";
runner.update(conn,sql2);
conn.commit();
}finally{
if(conn!=null){
conn.close();
}
}
}
}
Demo1
package cn.itcast.dbutils.demo;
import java.sql.SQLException;
import java.util.Date;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.junit.Test;
import cn.itcast.domain.User;
import cn.itcast.utils.JdbcUtils;
public class Demo1 {
/*
create database day17;
use day17;
create table users(
id int primary key,
name varchar(40),
password varchar(40),
email varchar(60),
birthday date
);
*/
//使用dbutils完成数据库的crud
@Test
public void insert() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "insert into users(id,name,password,email,birthday) values(?,?,?,?,?)";
Object params[] = {2,"bbb","123","aa@sina.com",new Date()};
runner.update(sql, params);
}
@Test
public void update() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "update users set email=? where id=?";
Object params[] = {"aaaaaa@sina.com",1};
runner.update(sql, params);
}
@Test
public void delete() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "delete from users where id=?";
runner.update(sql, 1);
}
@Test
public void find() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users where id=?";
User user = (User) runner.query(sql, 1, new BeanHandler(User.class));
System.out.println(user.getEmail());
}
@Test
public void getAll() throws Exception{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users";
List list = (List) runner.query(sql, new BeanListHandler(User.class));
System.out.println(list);
}
@Test
public void batch() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "insert into users(id,name,password,email,birthday) values(?,?,?,?,?)";
Object params[][] = new Object[3][5];
for(int i=0;i<params.length;i++){ //3
params[i] = new Object[]{i+1,"aa"+i,"123",i + "@sina.com",new Date()};
}
runner.batch(sql, params);
}
}
Demo2
package cn.itcast.dbutils.demo;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.ArrayHandler;
import org.apache.commons.dbutils.handlers.ArrayListHandler;
import org.apache.commons.dbutils.handlers.KeyedHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.Test;
import cn.itcast.utils.JdbcUtils;
public class Demo2 {
//测试dbutils的各个结果集处理器
@Test
public void test1() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users";
Object result[] = (Object[]) runner.query(sql, new ArrayHandler());
System.out.println(result[0]);
System.out.println(result[1]);
}
@Test
public void test2() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users";
List list = (List) runner.query(sql, new ArrayListHandler());
System.out.println(list);
}
@Test
public void test3() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users";
List list = (List) runner.query(sql, new ColumnListHandler1("name"));
System.out.println(list);
}
@Test
public void test4() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from users";
Map<Integer,Map<String,Object>> map = (Map) runner.query(sql, new KeyedHandler("id"));
for(Map.Entry<Integer,Map<String,Object>> me : map.entrySet()){
int id = me.getKey();
for(Map.Entry<String, Object> entry : me.getValue().entrySet()){
String name = entry.getKey();
Object value = entry.getValue();
System.out.println(name + "=" + value);
}
}
}
@Test
public void test5() throws SQLException{
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select count(*) from users";
//Object result[] = (Object[]) runner.query(sql, new ArrayHandler());
/*long totalrecord = (Long)result[0];
int num = (int)totalrecord;
System.out.println(num);
int totalrecord = ((Long)result[0]).intValue();
*/
int totalrecord = ((Long)runner.query(sql, new ScalarHandler(1))).intValue();
System.out.println(totalrecord);
}
}
class ColumnListHandler1 implements ResultSetHandler{
private String columnName;
public ColumnListHandler1(String columnName){
this.columnName = columnName;
}
public Object handle(ResultSet rs) throws SQLException {
List list = new ArrayList();
while(rs.next()){
list.add(rs.getObject(columnName));
}
return list;
}
}
2.SERVER层
BusinessService
package cn.itcast.service;
import java.sql.Connection;
import java.sql.SQLException;
import org.junit.Test;
import cn.itcast.dbutils.demo.AccountDao;
import cn.itcast.domain.Account;
import cn.itcast.utils.JdbcUtils;
public class BusinessService {
/*
create table account(
id int primary key auto_increment,
name varchar(40),
money float
)character set utf8 collate utf8_general_ci;
insert into account(name,money) values('aaa',1000);
insert into account(name,money) values('bbb',1000);
insert into account(name,money) values('ccc',1000);
*/
@Test
public void test() throws SQLException{
transfer2(1, 2, 100);
}
public void transfer1(int sourceid,int targetid,double money) throws SQLException{
Connection conn = null;
try{
conn = JdbcUtils.getConnection();
conn.setAutoCommit(false);
AccountDao dao = new AccountDao(conn);
Account a = dao.find(sourceid); //select
Account b = dao.find(targetid); //select
a.setMoney(a.getMoney()-money);
b.setMoney(b.getMoney()+money);
dao.update(a); //update
dao.update(b);//update
conn.commit();
}finally{
if(conn!=null) conn.close();
}
}
//用上ThreadLocal的事务管理
public void transfer2(int sourceid,int targetid,double money) throws SQLException{
try{
JdbcUtils.startTransaction();
AccountDao dao = new AccountDao();
Account a = dao.find(sourceid); //select
Account b = dao.find(targetid); //select
a.setMoney(a.getMoney()-money);
b.setMoney(b.getMoney()+money);
dao.update(a); //update
dao.update(b);//update
JdbcUtils.commitTransaction();
}finally{
JdbcUtils.closeConnection();
}
}
}
3.Servlet 层
4.工具层 Util层
JdbcUtils
package cn.itcast.utils;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSourceFactory;
public class JdbcUtils {
private static DataSource ds;
private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); //map
static{
try{
Properties prop = new Properties();
InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("dbcpconfig.properties");
prop.load(in);
BasicDataSourceFactory factory = new BasicDataSourceFactory();
ds = factory.createDataSource(prop);
}catch (Exception e) {
throw new ExceptionInInitializerError(e);
}
}
public static DataSource getDataSource(){
return ds;
}
public static Connection getConnection() throws SQLException{
try{
//得到当前线程上绑定的连接
Connection conn = tl.get();
if(conn==null){ //代表线程上没有绑定连接
conn = ds.getConnection();
tl.set(conn);
}
return conn;
}catch (Exception e) {
throw new RuntimeException(e);
}
}
public static void startTransaction(){
try{
//得到当前线程上绑定连接开启事务
Connection conn = tl.get();
if(conn==null){ //代表线程上没有绑定连接
conn = ds.getConnection();
tl.set(conn);
}
conn.setAutoCommit(false);
}catch (Exception e) {
throw new RuntimeException(e);
}
}
public static void commitTransaction(){
try{
Connection conn = tl.get();
if(conn!=null){
conn.commit();
}
}catch (Exception e) {
throw new RuntimeException(e);
}
}
public static void closeConnection(){
try{
Connection conn = tl.get();
if(conn!=null){
conn.close();
}
}catch (Exception e) {
throw new RuntimeException(e);
}finally{
tl.remove(); //千万注意,解除当前线程上绑定的链接(从threadlocal容器中移除对应当前线程的链接)
}
}
}
5.Domain 层
package cn.itcast.domain;
import java.util.Date;
public class User {
private int id;
private String name;
private String password;
private String email;
private Date birthday;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
}
Account层
package cn.itcast.domain;
public class Account {
private int id;
private String name;
private double money;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getMoney() {
return money;
}
public void setMoney(double money) {
this.money = money;
}
}
dbcpconfig.properties
#连接设置
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/day17
username=root
password=root
#<!-- 初始化连接 -->
initialSize=10
#最大连接数量
maxActive=50
#<!-- 最大空闲连接 -->
maxIdle=20
#<!-- 最小空闲连接 -->
minIdle=5
#<!-- 超时等待时间以毫秒为单位 6000毫秒/1000等于60秒 -->
maxWait=60000
#JDBC驱动建立连接时附带的连接属性属性的格式必须为这样:[属性名=property;]
#注意:"user" 与 "password" 两个属性会被明确地传递,因此这里不需要包含他们。
connectionProperties=useUnicode=true;characterEncoding=utf8
#指定由连接池所创建的连接的自动提交(auto-commit)状态。
defaultAutoCommit=true
#driver default 指定由连接池所创建的连接的只读(read-only)状态。
#如果没有设置该值,则“setReadOnly”方法将不被调用。(某些驱动并不支持只读模式,如:Informix)
defaultReadOnly=
#driver default 指定由连接池所创建的连接的事务级别(TransactionIsolation)。
#可用值为下列之一:(详情可见javadoc。)NONE,READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ, SERIALIZABLE
defaultTransactionIsolation=READ_COMMITTED