ConstClass
public class ConstClass {
public static final String MYDB_CONF_NAME="mydb.properties";
public static final String MYSQL_DRIVER_STR="mysqldriver";
public static final String MYSQL_USER_STR="user";
public static final String MYSQL_PWD_STR="password";
public static final String MYSQL_URL_STR="url";
public static final String MYSQL_MAX_STR="max";
public static final String MYSQL_MIN_STR="min";
public static final String MYSQL_INCREASE_STR="increase";
public static final String MYSQL_INIT_STR="initNum";
}
JdbcUtils
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
public class JdbcUtils {
private static String driver;
private static String url;
private static String user;
private static String pwd;
static {
try {
Properties properties = PropertyUtils.getProperties(ConstClass.MYDB_CONF_NAME);
driver = properties.getProperty(ConstClass.MYSQL_DRIVER_STR);
url = properties.getProperty(ConstClass.MYSQL_URL_STR);
user = properties.getProperty(ConstClass.MYSQL_USER_STR);
pwd = properties.getProperty(ConstClass.MYSQL_PWD_STR);
} catch (IOException e) {
e.printStackTrace();
}
}
public static Connection getConnection(){
Connection connection = null;
try {
Class.forName(driver);
connection = DriverManager.getConnection(url, user, pwd);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
// 释放Connection连接
public static void close(Connection conn, PreparedStatement pstmt, ResultSet rs){
if (rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(pstmt!=null){
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close(Connection conn, PreparedStatement pstmt){
close(conn, pstmt, null);
}
public static void close(Connection conn){
close(conn,null,null);
}
public static void main(String[] args) {
for(int i=0; i<200;i++){
new Thread(new Runnable() {
@Override
public void run() {
Connection connection = JdbcUtils.getConnection();
System.out.println(connection);
JdbcUtils.close(connection);
}
}).start();
}
}
}
MyConnectionPool
import java.io.IOException;
import java.sql.Connection;
import java.util.linkedList;
import java.util.Properties;
public class MyConnectionPool {
private Integer initNum = 100; // 初始化Connection的数量
private Integer min = 30; // 允许连接池中拥有Connection的最小数量
private Integer max = 150; // 允许连接池中拥有Connection的最大数量
private Integer increase = 30; // 每次与数据库创建Connection的数量
private Byte b = 1; // 同步锁 标记
private Boolean xiaofango = false; // 跑腿去购买Connection的人，是否已经出去购买 true：表示已经去购买 false：表示在家
// 用于存放Connection对象
private linkedList pool = new linkedList<>();
// 用于创建 Connection 的私有方法
private void produceConnection(Integer num){
for (int i = 0; i < num; i++) {
if(checkPoolMaxNum()) {
// 创建 Connection 对象
Connection conn = JdbcUtils.getConnection();
pool.add(conn);
xiaofango=false;
}
}
}
private boolean checkPoolMaxNum(){
if(pool.size()>=max){
return false;
}
return true;
}
private MyConnectionPool(){
try {
Properties prop = PropertyUtils.getProperties("mydb.properties");
String property = prop.getProperty(ConstClass.MYSQL_INCREASE_STR);
increase = prop.getProperty(ConstClass.MYSQL_INCREASE_STR)==null?increase: Integer.parseInt(prop.getProperty(ConstClass.MYSQL_INCREASE_STR)) ;
max = prop.getProperty(ConstClass.MYSQL_MAX_STR)==null?max: Integer.parseInt(prop.getProperty(ConstClass.MYSQL_MAX_STR));
min =prop.getProperty(ConstClass.MYSQL_MIN_STR)==null? min: Integer.parseInt(prop.getProperty(ConstClass.MYSQL_MIN_STR));
initNum = prop.getProperty(ConstClass.MYSQL_INIT_STR)==null? increase:Integer.parseInt(prop.getProperty(ConstClass.MYSQL_INIT_STR));
produceConnection(initNum);
} catch (IOException e) {
e.printStackTrace();
}
}
// 提供 Connection 对象
public Connection getConnection(){
synchronized (b){
while (pool.size()==0){
System.out.println("waring,连接池中没有Connection对象。。。。。。");
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
if(pool.size()<=min && !xiaofango){
xiaofango=true;
new Thread(new Runnable() {
@Override
public void run() {
produceConnection(increase);
}
}).start();
}
return pool.pop();
}
}
// 还回 Connection 对象
public void close(Connection conn){
if(pool.size()>max){
JdbcUtils.close(conn);
}else {
pool.add(conn);
}
}
private static MyConnectionPool poolInstance = new MyConnectionPool();
public static MyConnectionPool getPoolInstance(){
return poolInstance;
}
public static void main(String[] args) {
// MyConnectionPool myConnectionPool = new MyConnectionPool();
for (int i = 0; i < 10; i++) {
new Thread(new Runnable() {
@Override
public void run() {
//
MyConnectionPool source = MyConnectionPool.getPoolInstance();
Connection connection = source.getConnection();
System.out.println(Thread.currentThread().getName()+""+ connection);
source.close(connection);
}
}).start();
}
}
}
MyPoolUtils
import java.sql.Connection;
public class MyPoolUtils {
static MyConnectionPool source=MyConnectionPool.getPoolInstance();
public static Connection getConnection(){
Connection connection=null;
connection =source.getConnection();
return connection;
}
public static void close(Connection connection){
source.close(connection);}
public static void main(String[] args) {
for(int i=0;i<5;i++){
Connection connection = MyPoolUtils.getConnection();
System.out.println(connection);
MyPoolUtils.close(connection);
}
}
}
PropertyUtils
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class PropertyUtils {
public static Properties getProperties(String proFileName) throws IOException {
ClassLoader classLoader = PropertyUtils.class.getClassLoader();
InputStream is = classLoader.getResourceAsStream(proFileName);
Properties props = new Properties();
props.load(is);
return props;
}
public static void main(String[] args) throws IOException {
Properties props = PropertyUtils.getProperties("mydb.properties");
String driver = props.getProperty("mysqldriver");
String url = props.getProperty("url");
String user = props.getProperty("user");
String pwd = props.getProperty("password");
System.out.println(driver);
System.out.println(url);
System.out.println(user);
System.out.println(pwd);
}
}
TestMyPool
public class TestMyPool {
public static void main(String[] args) {
// MyConnectionPool myConnectionPool = new MyConnectionPool();
}
}
