opc connection

Summary: I was a little confused about these concepts. I checked some materials and summarized their differences. If any error occurs, take a picture ~~~ First look at the figure: What is TCP/IP? TCP/IP is a protocol group, which can be divided into three layers: network layer, transport layer and application layer.The IP protocol, ICMP protocol, ARP protocol, RARP protocol, and BOOTP protocol are available at the network layer.There are TCP and UDP protocols in the transport layer.The

Keep HTTP Connection Reference the following descriptions on the website:Most Web browsers require the server to keep the connection open in multiple requests. This is called to maintain an HTTP connection. Keep the connection is an HTTPSpecifications, which can significantly enhance server performance. Without it, the

Label:Proxy Mode Requirements: Extend (enhance) the functionality of a class already in the system Requirements: In the case of non-modification of the source code, the existing functions are enhanced Static proxy Abstract interface: An object that guarantees an object with enhanced functionality and an existing function, providing the same method externally Target object: Encapsulates the original functionality Proxy object: Encapsulates enhancements and legacy functionality (implemented by hol

C3P0 connection pool, DBCP connection pool, C3P0 connection pool: Profile: c3p0-config.xml Test: Data preparation: CREATE DATABASE mybase;USE mybase;CREATE TABLE users(uid INT PRIMARY KEY AUTO_INCREMENT,username VARCHAR(64),upassword VARCHAR(64));INSERT INTO users (username,upassword) VALUES("zhangsan","123"),("lisi","456"),("wangwu","789");SELECT * FROM users;V

DruidDataSource connection pool configuration, druiddatasource connection Data source connection pool Configuration The maximum number of database connections in the connection pool. If it is set to 0, there is no limit. You can set maxActive to a possible concurrency.Initialization sizeMaximum number of waits in mil

Use jar Packs: Commons-dbcp-1.4.jar, Commons-pool-1.6.jar, Commons-logging-1.1.3.jar, plus JDBC driver for the database, for JAVA6 and above platforms Connection Pooling Management class Copy Code code as follows: Package cn.songxinqiang.samples.commonsdbcp.util; Import java.sql.Connection;Import Java.sql.DatabaseMetaData;Import java.sql.SQLException;Import java.util.Properties; Import Javax.sql.DataSource; Import Org.apache.common

connection pool (not the C3P0 connection pool used here) to get the database connection, so the connection pool must be constructed first. Here are four actions: Add and delete and check @Test public Void Add () { //because JdbcTemplate is dependent on the database

Today, an httpclient exception is solved. Khan, a httpclient can be destroyed if it is used accidentally. Here is a previously handled server exception caused by improper route configuration: http://blog.csdn.net/shootyou/article/details/6415248 The httpconnectionmanager implementation is what I use here. Problem: A large number of exceptions are found in Tomcat background logs. org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for conne