連接池的管理用了了享元模式,這里對連接池進行簡單設計。
一、設計思路
1.連接池配置屬性DBbean:里面存放可以配置的一些屬性
2.連接池接口IConnectionPool:里面定義一些基本的獲取連接的一些方法
3.接口實現ConnectionPool:對上面操作進行實現,並加入一些其他方法
4.連接池管理ConnectionPoolManager:管理所有的不同的連接池,所有的連接都能通過這里進行獲得連接
5.另外還有幾個測試類,和連接信息模擬的類,這里就不進行xml 和配置文件信息的讀取了
- package pool;
- /**
- * 這是外部可以配置的連接池屬性
- * 可以允許外部配置,擁有默認值
- * @author Ran
- *
- */
- public class DBbean {
- // 連接池屬性
- private String driverName;
- private String url;
- private String userName;
- private String password;
- // 連接池名字
- private String poolName;
- private int minConnections = 1; // 空閑池,最小連接數
- private int maxConnections = 10; // 空閑池,最大連接數
- private int initConnections = 5;// 初始化連接數
- private long connTimeOut = 1000;// 重復獲得連接的頻率
- private int maxActiveConnections = 100;// 最大允許的連接數,和數據庫對應
- private long connectionTimeOut = 1000*60*20;// 連接超時時間,默認20分鍾
- private boolean isCurrentConnection = true; // 是否獲得當前連接,默認true
- private boolean isCheakPool = true; // 是否定時檢查連接池
- private long lazyCheck = 1000*60*60;// 延遲多少時間后開始 檢查
- private long periodCheck = 1000*60*60;// 檢查頻率
- public DBbean(String driverName, String url, String userName,
- String password, String poolName) {
- super();
- this.driverName = driverName;
- this.url = url;
- this.userName = userName;
- this.password = password;
- this.poolName = poolName;
- }
- public DBbean() {
- }
- public String getDriverName() {
- if(driverName == null){
- driverName = this.getDriverName()+"_"+this.getUrl();
- }
- return driverName;
- }
- public void setDriverName(String driverName) {
- this.driverName = driverName;
- }
- public String getUrl() {
- return url;
- }
- public void setUrl(String url) {
- this.url = url;
- }
- public String getUserName() {
- return userName;
- }
- public void setUserName(String userName) {
- this.userName = userName;
- }
- public String getPassword() {
- return password;
- }
- public void setPassword(String password) {
- this.password = password;
- }
- public String getPoolName() {
- return poolName;
- }
- public void setPoolName(String poolName) {
- this.poolName = poolName;
- }
- public int getMinConnections() {
- return minConnections;
- }
- public void setMinConnections(int minConnections) {
- this.minConnections = minConnections;
- }
- public int getMaxConnections() {
- return maxConnections;
- }
- public void setMaxConnections(int maxConnections) {
- this.maxConnections = maxConnections;
- }
- public int getInitConnections() {
- return initConnections;
- }
- public void setInitConnections(int initConnections) {
- this.initConnections = initConnections;
- }
- public int getMaxActiveConnections() {
- return maxActiveConnections;
- }
- public void setMaxActiveConnections(int maxActiveConnections) {
- this.maxActiveConnections = maxActiveConnections;
- }
- public long getConnTimeOut() {
- return connTimeOut;
- }
- public void setConnTimeOut(long connTimeOut) {
- this.connTimeOut = connTimeOut;
- }
- public long getConnectionTimeOut() {
- return connectionTimeOut;
- }
- public void setConnectionTimeOut(long connectionTimeOut) {
- this.connectionTimeOut = connectionTimeOut;
- }
- public boolean isCurrentConnection() {
- return isCurrentConnection;
- }
- public void setCurrentConnection(boolean isCurrentConnection) {
- this.isCurrentConnection = isCurrentConnection;
- }
- public long getLazyCheck() {
- return lazyCheck;
- }
- public void setLazyCheck(long lazyCheck) {
- this.lazyCheck = lazyCheck;
- }
- public long getPeriodCheck() {
- return periodCheck;
- }
- public void setPeriodCheck(long periodCheck) {
- this.periodCheck = periodCheck;
- }
- public boolean isCheakPool() {
- return isCheakPool;
- }
- public void setCheakPool(boolean isCheakPool) {
- this.isCheakPool = isCheakPool;
- }
- }
package pool; /** * 這是外部可以配置的連接池屬性 * 可以允許外部配置,擁有默認值 * @author Ran * */ public class DBbean { // 連接池屬性 private String driverName; private String url; private String userName; private String password; // 連接池名字 private String poolName; private int minConnections = 1; // 空閑池,最小連接數 private int maxConnections = 10; // 空閑池,最大連接數 private int initConnections = 5;// 初始化連接數 private long connTimeOut = 1000;// 重復獲得連接的頻率 private int maxActiveConnections = 100;// 最大允許的連接數,和數據庫對應 private long connectionTimeOut = 1000*60*20;// 連接超時時間,默認20分鍾 private boolean isCurrentConnection = true; // 是否獲得當前連接,默認true private boolean isCheakPool = true; // 是否定時檢查連接池 private long lazyCheck = 1000*60*60;// 延遲多少時間后開始 檢查 private long periodCheck = 1000*60*60;// 檢查頻率 public DBbean(String driverName, String url, String userName, String password, String poolName) { super(); this.driverName = driverName; this.url = url; this.userName = userName; this.password = password; this.poolName = poolName; } public DBbean() { } public String getDriverName() { if(driverName == null){ driverName = this.getDriverName()+"_"+this.getUrl(); } return driverName; } public void setDriverName(String driverName) { this.driverName = driverName; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getPoolName() { return poolName; } public void setPoolName(String poolName) { this.poolName = poolName; } public int getMinConnections() { return minConnections; } public void setMinConnections(int minConnections) { this.minConnections = minConnections; } public int getMaxConnections() { return maxConnections; } public void setMaxConnections(int maxConnections) { this.maxConnections = maxConnections; } public int getInitConnections() { return initConnections; } public void setInitConnections(int initConnections) { this.initConnections = initConnections; } public int getMaxActiveConnections() { return maxActiveConnections; } public void setMaxActiveConnections(int maxActiveConnections) { this.maxActiveConnections = maxActiveConnections; } public long getConnTimeOut() { return connTimeOut; } public void setConnTimeOut(long connTimeOut) { this.connTimeOut = connTimeOut; } public long getConnectionTimeOut() { return connectionTimeOut; } public void setConnectionTimeOut(long connectionTimeOut) { this.connectionTimeOut = connectionTimeOut; } public boolean isCurrentConnection() { return isCurrentConnection; } public void setCurrentConnection(boolean isCurrentConnection) { this.isCurrentConnection = isCurrentConnection; } public long getLazyCheck() { return lazyCheck; } public void setLazyCheck(long lazyCheck) { this.lazyCheck = lazyCheck; } public long getPeriodCheck() { return periodCheck; } public void setPeriodCheck(long periodCheck) { this.periodCheck = periodCheck; } public boolean isCheakPool() { return isCheakPool; } public void setCheakPool(boolean isCheakPool) { this.isCheakPool = isCheakPool; } }
- package pool;
- import java.sql.Connection;
- import java.sql.SQLException;
- public interface IConnectionPool {
- // 獲得連接
- public Connection getConnection();
- // 獲得當前連接
- public Connection getCurrentConnecton();
- // 回收連接
- public void releaseConn(Connection conn) throws SQLException;
- // 銷毀清空
- public void destroy();
- // 連接池是活動狀態
- public boolean isActive();
- // 定時器,檢查連接池
- public void cheackPool();
- }
package pool; import java.sql.Connection; import java.sql.SQLException; public interface IConnectionPool { // 獲得連接 public Connection getConnection(); // 獲得當前連接 public Connection getCurrentConnecton(); // 回收連接 public void releaseConn(Connection conn) throws SQLException; // 銷毀清空 public void destroy(); // 連接池是活動狀態 public boolean isActive(); // 定時器,檢查連接池 public void cheackPool(); }
- package pool;
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.SQLException;
- import java.util.List;
- import java.util.Timer;
- import java.util.TimerTask;
- import java.util.Vector;
- public class ConnectionPool implements IConnectionPool {
- // 連接池配置屬性
- private DBbean dbBean;
- private boolean isActive = false; // 連接池活動狀態
- private int contActive = 0;// 記錄創建的總的連接數
- // 空閑連接
- private List<Connection> freeConnection = new Vector<Connection>();
- // 活動連接
- private List<Connection> activeConnection = new Vector<Connection>();
- // 將線程和連接綁定,保證事務能統一執行
- private static ThreadLocal<Connection> threadLocal = new ThreadLocal<Connection>();
- public ConnectionPool(DBbean dbBean) {
- super();
- this.dbBean = dbBean;
- init();
- cheackPool();
- }
- // 初始化
- public void init() {
- try {
- Class.forName(dbBean.getDriverName());
- for (int i = 0; i < dbBean.getInitConnections(); i++) {
- Connection conn;
- conn = newConnection();
- // 初始化最小連接數
- if (conn != null) {
- freeConnection.add(conn);
- contActive++;
- }
- }
- isActive = true;
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- // 獲得當前連接
- public Connection getCurrentConnecton(){
- // 默認線程里面取
- Connection conn = threadLocal.get();
- if(!isValid(conn)){
- conn = getConnection();
- }
- return conn;
- }
- // 獲得連接
- public synchronized Connection getConnection() {
- Connection conn = null;
- try {
- // 判斷是否超過最大連接數限制
- if(contActive < this.dbBean.getMaxActiveConnections()){
- if (freeConnection.size() > 0) {
- conn = freeConnection.get(0);
- if (conn != null) {
- threadLocal.set(conn);
- }
- freeConnection.remove(0);
- } else {
- conn = newConnection();
- }
- }else{
- // 繼續獲得連接,直到從新獲得連接
- wait(this.dbBean.getConnTimeOut());
- conn = getConnection();
- }
- if (isValid(conn)) {
- activeConnection.add(conn);
- contActive ++;
- }
- } catch (SQLException e) {
- e.printStackTrace();
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (InterruptedException e) {
- e.printStackTrace();
- }
- return conn;
- }
- // 獲得新連接
- private synchronized Connection newConnection()
- throws ClassNotFoundException, SQLException {
- Connection conn = null;
- if (dbBean != null) {
- Class.forName(dbBean.getDriverName());
- conn = DriverManager.getConnection(dbBean.getUrl(),
- dbBean.getUserName(), dbBean.getPassword());
- }
- return conn;
- }
- // 釋放連接
- public synchronized void releaseConn(Connection conn) throws SQLException {
- if (isValid(conn)&& !(freeConnection.size() > dbBean.getMaxConnections())) {
- freeConnection.add(conn);
- activeConnection.remove(conn);
- contActive --;
- threadLocal.remove();
- // 喚醒所有正待等待的線程,去搶連接
- notifyAll();
- }
- }
- // 判斷連接是否可用
- private boolean isValid(Connection conn) {
- try {
- if (conn == null || conn.isClosed()) {
- return false;
- }
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return true;
- }
- // 銷毀連接池
- public synchronized void destroy() {
- for (Connection conn : freeConnection) {
- try {
- if (isValid(conn)) {
- conn.close();
- }
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- for (Connection conn : activeConnection) {
- try {
- if (isValid(conn)) {
- conn.close();
- }
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- isActive = false;
- contActive = 0;
- }
- // 連接池狀態
- @Override
- public boolean isActive() {
- return isActive;
- }
- // 定時檢查連接池情況
- @Override
- public void cheackPool() {
- if(dbBean.isCheakPool()){
- new Timer().schedule(new TimerTask() {
- @Override
- public void run() {
- // 1.對線程里面的連接狀態
- // 2.連接池最小 最大連接數
- // 3.其他狀態進行檢查,因為這里還需要寫幾個線程管理的類,暫時就不添加了
- System.out.println("空線池連接數:"+freeConnection.size());
- System.out.println("活動連接數::"+activeConnection.size());
- System.out.println("總的連接數:"+contActive);
- }
- },dbBean.getLazyCheck(),dbBean.getPeriodCheck());
- }
- }
- }
package pool; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.List; import java.util.Timer; import java.util.TimerTask; import java.util.Vector; public class ConnectionPool implements IConnectionPool { // 連接池配置屬性 private DBbean dbBean; private boolean isActive = false; // 連接池活動狀態 private int contActive = 0;// 記錄創建的總的連接數 // 空閑連接 private List<Connection> freeConnection = new Vector<Connection>(); // 活動連接 private List<Connection> activeConnection = new Vector<Connection>(); // 將線程和連接綁定,保證事務能統一執行 private static ThreadLocal<Connection> threadLocal = new ThreadLocal<Connection>(); public ConnectionPool(DBbean dbBean) { super(); this.dbBean = dbBean; init(); cheackPool(); } // 初始化 public void init() { try { Class.forName(dbBean.getDriverName()); for (int i = 0; i < dbBean.getInitConnections(); i++) { Connection conn; conn = newConnection(); // 初始化最小連接數 if (conn != null) { freeConnection.add(conn); contActive++; } } isActive = true; } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } } // 獲得當前連接 public Connection getCurrentConnecton(){ // 默認線程里面取 Connection conn = threadLocal.get(); if(!isValid(conn)){ conn = getConnection(); } return conn; } // 獲得連接 public synchronized Connection getConnection() { Connection conn = null; try { // 判斷是否超過最大連接數限制 if(contActive < this.dbBean.getMaxActiveConnections()){ if (freeConnection.size() > 0) { conn = freeConnection.get(0); if (conn != null) { threadLocal.set(conn); } freeConnection.remove(0); } else { conn = newConnection(); } }else{ // 繼續獲得連接,直到從新獲得連接 wait(this.dbBean.getConnTimeOut()); conn = getConnection(); } if (isValid(conn)) { activeConnection.add(conn); contActive ++; } } catch (SQLException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } return conn; } // 獲得新連接 private synchronized Connection newConnection() throws ClassNotFoundException, SQLException { Connection conn = null; if (dbBean != null) { Class.forName(dbBean.getDriverName()); conn = DriverManager.getConnection(dbBean.getUrl(), dbBean.getUserName(), dbBean.getPassword()); } return conn; } // 釋放連接 public synchronized void releaseConn(Connection conn) throws SQLException { if (isValid(conn)&& !(freeConnection.size() > dbBean.getMaxConnections())) { freeConnection.add(conn); activeConnection.remove(conn); contActive --; threadLocal.remove(); // 喚醒所有正待等待的線程,去搶連接 notifyAll(); } } // 判斷連接是否可用 private boolean isValid(Connection conn) { try { if (conn == null || conn.isClosed()) { return false; } } catch (SQLException e) { e.printStackTrace(); } return true; } // 銷毀連接池 public synchronized void destroy() { for (Connection conn : freeConnection) { try { if (isValid(conn)) { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } } for (Connection conn : activeConnection) { try { if (isValid(conn)) { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } } isActive = false; contActive = 0; } // 連接池狀態 @Override public boolean isActive() { return isActive; } // 定時檢查連接池情況 @Override public void cheackPool() { if(dbBean.isCheakPool()){ new Timer().schedule(new TimerTask() { @Override public void run() { // 1.對線程里面的連接狀態 // 2.連接池最小 最大連接數 // 3.其他狀態進行檢查,因為這里還需要寫幾個線程管理的類,暫時就不添加了 System.out.println("空線池連接數:"+freeConnection.size()); System.out.println("活動連接數::"+activeConnection.size()); System.out.println("總的連接數:"+contActive); } },dbBean.getLazyCheck(),dbBean.getPeriodCheck()); } } }
- package pool;
- import java.sql.Connection;
- import java.sql.SQLException;
- import java.util.Hashtable;
- /**
- * 連接管理類
- * @author Ran
- *
- */
- public class ConnectionPoolManager {
- // 連接池存放
- public Hashtable<String,IConnectionPool> pools = new Hashtable<String, IConnectionPool>();
- // 初始化
- private ConnectionPoolManager(){
- init();
- }
- // 單例實現
- public static ConnectionPoolManager getInstance(){
- return Singtonle.instance;
- }
- private static class Singtonle {
- private static ConnectionPoolManager instance = new ConnectionPoolManager();
- }
- // 初始化所有的連接池
- public void init(){
- for(int i =0;i<DBInitInfo.beans.size();i++){
- DBbean bean = DBInitInfo.beans.get(i);
- ConnectionPool pool = new ConnectionPool(bean);
- if(pool != null){
- pools.put(bean.getPoolName(), pool);
- System.out.println("Info:Init connection successed ->" +bean.getPoolName());
- }
- }
- }
- // 獲得連接,根據連接池名字 獲得連接
- public Connection getConnection(String poolName){
- Connection conn = null;
- if(pools.size()>0 && pools.containsKey(poolName)){
- conn = getPool(poolName).getConnection();
- }else{
- System.out.println("Error:Can't find this connecion pool ->"+poolName);
- }
- return conn;
- }
- // 關閉,回收連接
- public void close(String poolName,Connection conn){
- IConnectionPool pool = getPool(poolName);
- try {
- if(pool != null){
- pool.releaseConn(conn);
- }
- } catch (SQLException e) {
- System.out.println("連接池已經銷毀");
- e.printStackTrace();
- }
- }
- // 清空連接池
- public void destroy(String poolName){
- IConnectionPool pool = getPool(poolName);
- if(pool != null){
- pool.destroy();
- }
- }
- // 獲得連接池
- public IConnectionPool getPool(String poolName){
- IConnectionPool pool = null;
- if(pools.size() > 0){
- pool = pools.get(poolName);
- }
- return pool;
- }
- }
package pool; import java.sql.Connection; import java.sql.SQLException; import java.util.Hashtable; /** * 連接管理類 * @author Ran * */ public class ConnectionPoolManager { // 連接池存放 public Hashtable<String,IConnectionPool> pools = new Hashtable<String, IConnectionPool>(); // 初始化 private ConnectionPoolManager(){ init(); } // 單例實現 public static ConnectionPoolManager getInstance(){ return Singtonle.instance; } private static class Singtonle { private static ConnectionPoolManager instance = new ConnectionPoolManager(); } // 初始化所有的連接池 public void init(){ for(int i =0;i<DBInitInfo.beans.size();i++){ DBbean bean = DBInitInfo.beans.get(i); ConnectionPool pool = new ConnectionPool(bean); if(pool != null){ pools.put(bean.getPoolName(), pool); System.out.println("Info:Init connection successed ->" +bean.getPoolName()); } } } // 獲得連接,根據連接池名字 獲得連接 public Connection getConnection(String poolName){ Connection conn = null; if(pools.size()>0 && pools.containsKey(poolName)){ conn = getPool(poolName).getConnection(); }else{ System.out.println("Error:Can't find this connecion pool ->"+poolName); } return conn; } // 關閉,回收連接 public void close(String poolName,Connection conn){ IConnectionPool pool = getPool(poolName); try { if(pool != null){ pool.releaseConn(conn); } } catch (SQLException e) { System.out.println("連接池已經銷毀"); e.printStackTrace(); } } // 清空連接池 public void destroy(String poolName){ IConnectionPool pool = getPool(poolName); if(pool != null){ pool.destroy(); } } // 獲得連接池 public IConnectionPool getPool(String poolName){ IConnectionPool pool = null; if(pools.size() > 0){ pool = pools.get(poolName); } return pool; } }
- package pool;
- import java.util.ArrayList;
- import java.util.List;
- /**
- * 初始化,模擬加載所有的配置文件
- * @author Ran
- *
- */
- public class DBInitInfo {
- public static List<DBbean> beans = null;
- static{
- beans = new ArrayList<DBbean>();
- // 這里數據 可以從xml 等配置文件進行獲取
- // 為了測試,這里我直接寫死
- DBbean beanOracle = new DBbean();
- beanOracle.setDriverName("oracle.jdbc.driver.OracleDriver");
- beanOracle.setUrl("jdbc:oracle:thin:@7MEXGLUY95W1Y56:1521:orcl");
- beanOracle.setUserName("mmsoa");
- beanOracle.setPassword("password1234");
- beanOracle.setMinConnections(5);
- beanOracle.setMaxConnections(100);
- beanOracle.setPoolName("testPool");
- beans.add(beanOracle);
- }
- }
package pool; import java.util.ArrayList; import java.util.List; /** * 初始化,模擬加載所有的配置文件 * @author Ran * */ public class DBInitInfo { public static List<DBbean> beans = null; static{ beans = new ArrayList<DBbean>(); // 這里數據 可以從xml 等配置文件進行獲取 // 為了測試,這里我直接寫死 DBbean beanOracle = new DBbean(); beanOracle.setDriverName("oracle.jdbc.driver.OracleDriver"); beanOracle.setUrl("jdbc:oracle:thin:@7MEXGLUY95W1Y56:1521:orcl"); beanOracle.setUserName("mmsoa"); beanOracle.setPassword("password1234"); beanOracle.setMinConnections(5); beanOracle.setMaxConnections(100); beanOracle.setPoolName("testPool"); beans.add(beanOracle); } }
測試:
- package pool;
- import java.sql.Connection;
- /**
- * 模擬線程啟動,去獲得連接
- * @author Ran
- *
- */
- public class ThreadConnection implements Runnable{
- private IConnectionPool pool;
- @Override
- public void run() {
- pool = ConnectionPoolManager.getInstance().getPool("testPool");
- }
- public Connection getConnection(){
- Connection conn = null;
- if(pool != null && pool.isActive()){
- conn = pool.getConnection();
- }
- return conn;
- }
- public Connection getCurrentConnection(){
- Connection conn = null;
- if(pool != null && pool.isActive()){
- conn = pool.getCurrentConnecton();
- }
- return conn;
- }
- }
package pool; import java.sql.Connection; /** * 模擬線程啟動,去獲得連接 * @author Ran * */ public class ThreadConnection implements Runnable{ private IConnectionPool pool; @Override public void run() { pool = ConnectionPoolManager.getInstance().getPool("testPool"); } public Connection getConnection(){ Connection conn = null; if(pool != null && pool.isActive()){ conn = pool.getConnection(); } return conn; } public Connection getCurrentConnection(){ Connection conn = null; if(pool != null && pool.isActive()){ conn = pool.getCurrentConnecton(); } return conn; } }
- package pool;
- public class Client {
- public static void main(String[] args) throws InterruptedException {
- // 初始化連接池
- Thread t = init();
- t.start();
- t.join();
- ThreadConnection a = new ThreadConnection();
- ThreadConnection b = new ThreadConnection();
- ThreadConnection c = new ThreadConnection();
- Thread t1 = new Thread(a);
- Thread t2 = new Thread(b);
- Thread t3 = new Thread(c);
- // 設置優先級,先讓初始化執行,模擬 線程池 先啟動
- // 這里僅僅表面控制了,因為即使t 線程先啟動,也不能保證pool 初始化完成,為了簡單模擬,這里先這樣寫了
- t1.setPriority(10);
- t2.setPriority(10);
- t3.setPriority(10);
- t1.start();
- t2.start();
- t3.start();
- System.out.println("線程A-> "+a.getConnection());
- System.out.println("線程B-> "+b.getConnection());
- System.out.println("線程C-> "+c.getConnection());
- }
- // 初始化
- public static Thread init() {
- Thread t = new Thread(new Runnable() {
- @Override
- public void run() {
- IConnectionPool pool = initPool();
- while(pool == null || !pool.isActive()){
- pool = initPool();
- }
- }
- });
- return t;
- }
- public static IConnectionPool initPool(){
- return ConnectionPoolManager.getInstance().getPool("testPool");
- }
- }
package pool; public class Client { public static void main(String[] args) throws InterruptedException { // 初始化連接池 Thread t = init(); t.start(); t.join(); ThreadConnection a = new ThreadConnection(); ThreadConnection b = new ThreadConnection(); ThreadConnection c = new ThreadConnection(); Thread t1 = new Thread(a); Thread t2 = new Thread(b); Thread t3 = new Thread(c); // 設置優先級,先讓初始化執行,模擬 線程池 先啟動 // 這里僅僅表面控制了,因為即使t 線程先啟動,也不能保證pool 初始化完成,為了簡單模擬,這里先這樣寫了 t1.setPriority(10); t2.setPriority(10); t3.setPriority(10); t1.start(); t2.start(); t3.start(); System.out.println("線程A-> "+a.getConnection()); System.out.println("線程B-> "+b.getConnection()); System.out.println("線程C-> "+c.getConnection()); } // 初始化 public static Thread init() { Thread t = new Thread(new Runnable() { @Override public void run() { IConnectionPool pool = initPool(); while(pool == null || !pool.isActive()){ pool = initPool(); } } }); return t; } public static IConnectionPool initPool(){ return ConnectionPoolManager.getInstance().getPool("testPool"); } }
小結 :
1.連接池誕生原因是,如果每次都從數據庫獲得連接,時間比較長,因此我們提前做建立一些連接,放在連接池里面,每次都從里面取
2.上面僅僅寫了連接池基本原理,關於多線程下連接池的管理沒寫,后面對多線程操作熟練了添加吧