Shulou(Shulou.com)06/01 Report--

Database-Mysql (JDBC implementation & solving the problem of storage garbled)

1, the solution to the garbled problem is very simple!

First of all, when you set up the database, you need to specify the character set as utf-8, and then when you program with JDBC, add the parameter characterEncoding after the url of the following code! For more information on the settings of url parameters, please see the documentation on mysql's official website:

Http://dev.mysql.com/doc/connector-j/5.1/en/connector-j-reference-configuration-properties.html

2. The JDBC URL format for Connector/J of MySQL is as follows:

Jdbc:mysql:// [host] [, failoverhost...] [: port] / [database]

[? propertyName1] [= propertyValue1] [& propertyName2] [= propertyValue2]...

Jdbc:mysql:// [host:port], [host:port]... / [database]

[? propertyName1] [= propertyValue1] [& propertyName2] [= propertyValue2]...

Example:

Jdbc:mysql://localhost:3306/sakila?profileSQL=true

Package java_data_jdbc

Only a few important parameters are listed, as shown in the following table:

Parameter name Parameter description default minimum version requires user database user name (used to connect to the database)

All versions of password user password (used to connect to the database)

Whether all versions of useUnicode use the Unicode character set. If the parameter characterEncoding is set to gb2312 or gbk, the value of this parameter must be set to truefalse1.1gcharacterEncoding. When useUnicode is set to true, specify the character encoding. For example, it can be set to gb2312 or gbkfalse1.1gautoReconnect. Does it reconnect automatically when the database connection is broken abnormally? Does false1.1autoReconnectForPools use the reconnection policy for database connection pooling false3.1.3failOverReadOnly to automatically reconnect, and is the connection set to read-only after successful reconnection? When true3.0.12maxReconnectsautoReconnect is set to true and the number of retry connections is set to true, the time interval between two reconnections, in seconds, when 21.1connectTimeout and the database server establish a socket connection (in milliseconds). 0 means never timeout, applicable to JDK 1.4 and later 03.0.1socketTimeoutsocket operation (read and write) timeout (in milliseconds). 0 means never time out 03.0.1

For the Chinese environment, usually the mysql connection URL can be set to:

Jdbc:mysql://localhost:3306/test?user=root&password=&useUnicode=true&characterEncoding=gbk&autoReconnect=true&failOverReadOnly=false

In the case of database connection pooling, it is best to set the following two parameters:

AutoReconnect=true&failOverReadOnly=false

It is important to note that in the xml configuration file, the & symbol in url needs to be escaped to &. For example, when configuring database connection pooling in tomcat's server.xml, the mysql jdbc url example is as follows:

Jdbc:mysql://localhost:3306/test?user=root&password=&useUnicode=true&characterEncoding=gbk

& autoReconnect=true&failOverReadOnly=false

3. The code is as follows:

Import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class Jdbc_01 {public static void main (String [] args) {String userName = "root"; String password = "root" / * * this url format can be followed by many parameters. For more information, please refer to mysql official website http://dev.mysql.com/doc/connector-j/5.1/en/connector-j-reference-configuration-properties.html * / String url = "jdbc:mysql://localhost:3306?characterEncoding=utf-8&useSSL=true". String sql1 = "Select * from Class"; String sql = "INSERT INTO Class (name,age) VALUES ('Hello', '21')" Try {/ * * is written in two ways, the two are inherited, and the other is: org.gjt.mm.mysql.Driver * / Class.forName ("com.mysql.jdbc.Driver") Connection conn = DriverManager.getConnection (url, userName, password); Statement stmt = conn.createStatement (); stmt.execute ("use student;"); stmt.execute (sql) ResultSet res = stmt.executeQuery (sql1); while (res.next ()) {String id = res.getString ("id"); String name = res.getString ("name") Int age = res.getInt ("age"); System.out.println ("serial number:" + id + "" + "name:" + name + "" + age+ "year!") Catch (Exception e) {e.printStackTrace ();}

Partial source: http://elf8848.iteye.com/blog/1684414

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