Why is my Java application displaying distorted UTF-8 characters when interacting with a MySQL database?

Troubleshooting UTF-8 Encoding Issues in JDBC MySQL Interactions

In a Java-MySQL integration scenario using JDBC Connector 5.1, peculiar encoding issues arise when reading and writing UTF-8 data. Characters appear distorted or garbled, causing unexpected visualizations in both database interactions and web applications.

To solve this enigma, inspect the database settings:

character_set_client-->utf8
character_set_connection-->utf8
character_set_database-->utf8
...
character_set_server-->latin1
...

The issue stems from mismatched character sets. The database server uses 'latin1,' which does not support UTF-8 natively. To rectify this, explicitly set 'useUnicode' and 'characterEncoding' parameters in the JDBC connection string:

DriverManager.getConnection(
           "jdbc:mysql://" + host + "/" + dbName 
           + "?useUnicode=true&characterEncoding=UTF-8", user, pass);

This ensures that both reading and writing operations use UTF-8 consistently.

The problem may not be solely related to database configurations. Java applications may also handle UTF-8 incorrectly. If the encoding issue persists after adjusting database settings, consider decoding the data from the database using:

new String(data.getBytes("UTF-8"));

This converts the data to a UTF-8 string, enabling proper visualization in Java applications. However, avoid this as a general solution, as it may interfere with database writes.

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