008-ThreadLocal

一、基本用法

　　ThreadLocal是一个容器，用于存放线程的局部变量。如果ThreadLocalVariable(线程局部变量)更加好理解。

　　在Jdk 1.2 java.lang.ThreadLocal开始使用，他是为解决多线程并发设计的.

　　示例序列号生成，保证每个线程生成唯一序列号

编写Sequence接口

package com.lhx.test.dbutil2;

import java.sql.Connection;
import java.sql.DriverManager;

public class DBUtil {
private static final String driver = "com.mysql.jdbc.Driver";
private static final String url = "jdbc:mysql://localhost:3306/demo";
private static final String username = "root";
private static final String password = "root";

private static ThreadLocal<Connection> conContainer = new ThreadLocal<>();

public static Connection getConnection() {
Connection conn = conContainer.get();
try {
if (conn == null) {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
}
} catch (Exception e) {
e.printStackTrace();
}
finally {
conContainer.set(conn);
}
return conn;
}

public static void colseConnection() {
Connection conn = conContainer.get();
try {
if (conn != null) {
conn.close();
}
} catch (Exception e) {
e.printStackTrace();
}
finally {
conContainer.remove();
}
}
}

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