JDBC MySQL UTF-8字符串写入问题

连接到db：

public DBSource(ConnectionInfo ci) throws ClassNotFoundException, InstantiationException, IllegalAccessException, SQLException { Class.forName("com.mysql.jdbc.Driver").newInstance(); String dbPath = String.format( "jdbc:mysql://%s:%d/%s?user=%s&password=%s&characterEncoding=utf-8&" + "useUnicode=true", ci.host, ci.port, ci.dbName, ci.user, ci.password); conn = java.sql.DriverManager.getConnection(dbPath); prepareTables(); } 

表创建代码：

 private void prepareTables() throws SQLException { java.sql.Statement stat = conn.createStatement(); String query = "set names utf8"; stat.execute(query); query = "set character set utf8"; stat.execute(query); query = "show variables like '%char%'"; stat.execute(query); java.sql.ResultSet rs = stat.getResultSet(); while (rs.next()) { String k = rs.getString(1); String v = rs.getString(2); System.out.println(k + " - " + v); } query = "drop table if exists clt"; stat.execute(query); query = "create table clt" + "(" + " id bigint not null" + ", text varchar(50) not null" + ") default character set utf8"; stat.execute(query); } 

行插入：

 public void visit(Insert i) throws SQLException { String query = "insert into clt" + " (id, text) values (?, ?)"; java.sql.PreparedStatement stmt = conn.prepareStatement(query); if (i.rowData.id == 12656697) { String toOut = "<<< " + Long.toString(i.rowData.id) + " - " + i.rowData.text; System.out.println(toOut); } int it = 0; stmt.setLong(++it, i.rowData.id); stmt.setString(++it, i.rowData.text); stmt.execute(); stmt.close(); } 

检查数据：

  public void checkText() throws SQLException { java.sql.Statement stmt = conn.createStatement(); String query = "select id, text from clt where id = '12656697'"; stmt.execute(query); java.sql.ResultSet rs = stmt.getResultSet(); while (rs.next()) { String k = rs.getString(1); String v = rs.getString(2); String toOut = ">>> " + k + " - " + v; System.out.println(toOut); } } 

输出：

 character_set_client - utf8 character_set_connection - latin1 character_set_database - latin1 character_set_filesystem - binary character_set_results - utf8 character_set_server - utf8 character_set_system - utf8 character_sets_dir - /usr/share/mysql/charsets/ <<>> 12656697 - ??????? 

问题 ：在表格中，我在文本字段中有“ ??????????? ”符号。

预期的字符串是 ： Апарати
结果 ： ???????

这是某种魔力
我解决了一个问题…但如果smbd会向我解释，我仍会感激。
所以。

1. 我添加到Costis Aivalis建议的/etc/mysql/my.cnf行
   结果一样
2. 我从代码中删除了一行：
   query =“set character set utf8”;
   stat.execute（查询）;

这是工作！！！ 🙂

Answer 1

确保正确定义了MySQL配置编码。 使用以下命令检查您的设置和修改的正确性：

 show variables like 'character%'; 

并show variables like 'collation%';

将这些行添加到my.cnf或my.ini ：

对于MySQL 5.1.nn和更高版本5.5.29，您只需要这两行：

 [mysqld] character-set-server = utf8 character-set-filesystem = utf8 

对于MySQL 5.0.nn和更早版本，请使用以下设置：

 [client] default-character-set=utf8 

 [mysql] default-character-set=utf8 

 [mysqld] default-character-set=utf8 character-set-server=utf8 

使用MySQL-Workbench进行设置可能更方便。 版本5+非常好。

在您的Java程序中连接如下：

 con = DriverManager.getConnection("jdbc:mysql://localhost:3306/myDatabase?useUnicode=true&characterEncoding=UTF-8","user","passwd"); 

Answer 2

如果你得到????????? 添加参数characterEncoding=utf-8而不是useUnicode=true 。 请参阅以下示例。

对于英文文本：

 String url = "jdbc:mysql://localhost:" + port + "/DBName?useUnicode=true&..."; 

对于俄语laguage中的文本：

 String url = "jdbc:mysql://localhost:" + port + "/DBName&characterEncoding=utf-8&...";