Mysql connection url in useUnicode = true & amp; characterEncoding = UTF-8

Mysql connection url useUnicode = true & characterEncoding = UTF-8 in our connection to the mysql database will generally add useUnicode = true & characterEncoding = UTF-8 after the url, but what do you want to add? Www.2cto.com is used to specify the encoding and decoding formats of characters. For example, the mysql database uses gbk encoding, while the project database uses UTF-8 encoding. At this time, if useUnicode = true & characterEncoding = UTF-8 is added, the role of the following two aspects: 1. data storage: the database will first use the UTF-8 format to decode the data into bytecode, and then the decoded bytecode re-use GBK encoding to store in the database. 2. data Retrieval: When www.2cto.com retrieves data from the database, the database first decodes the data in the database into bytecode in GBK format, then encode the decoded bytecode again in UTF-8 format, and finally return the data to the client. Note: When configuring the database URL in the xml configuration file, use the & escape character, that is, & amp; for example: <property name = "url" value = "jdbc: mysql: // localhost: 3306/email? UseUnicode = true & amp; characterEncoding = UTF-8 "/> special characters commonly used in HTML: Character Entities) the display result indicates that Entity Name Entity Number displays a Space & nbsp; & #160; <less than & lt; & #60;> greater than & gt; & #62; & Symbol & amp; & #38; "Double quotation marks & quot; & #34; display result description of other commonly used Character Entities (Character Entities) Entity Name Entity Number? Copyright & copy; & #169 ;? Registered Trademark & reg; & #174; × multiplication number & times; & #215; except for "divide" & #247;