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java - 从 MySQL (JDBC,JSP) 显示文本时如何设置 UTF-8 编码

问题描述

我正在努力寻找解决这个编码问题的方法。我尝试了在 Internet/论坛上找到的几种替代方法，但它们似乎都不起作用。

连接类

public class ConnectionFactory {
public Connection getConnection() {
    try {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return DriverManager.getConnection("jdbc:mysql://localhost/fj21?useTimezone=true&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8", "root", "");
    } catch (SQLException e) {
        throw new RuntimeException(e);
    }
}
}

在我的 JSP 页面上，我使用了以下说明：

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>

在“my.cnf”文件中，我添加了：

[client]
default-character-set = utf8mb4

[mysql]
default-character-set = utf8mb4

[mysld]
default-character-set = utf8mb4
collation-server = utf8mb4_unicode_ci 
init-connect = 'SET NAMES utf8mb4'
character-set-server = utf8mb4
character-set-database = utf8mb4

我的 MySQL 变量是：

mysql> show variables like '%char%';
+--------------------------+---------------------------------------------------------+
| Variable_name            | Value                                                   |
+--------------------------+---------------------------------------------------------+
| character_set_client     | utf8                                                    |
| character_set_connection | utf8                                                    |
| character_set_database   | utf8mb4                                                 |
| character_set_filesystem | binary                                                  |
| character_set_results    | utf8                                                    |
| character_set_server     | utf8mb4                                                 |
| character_set_system     | utf8                                                    |
| character_sets_dir       | /usr/local/mysql-5.6.34-osx10.11-x86_64/share/charsets/ |
+--------------------------+---------------------------------------------------------+

mysql> show variables like '%coll%';
+----------------------+--------------------+
| Variable_name        | Value              |
+----------------------+--------------------+
| collation_connection | utf8_general_ci    |
| collation_database   | utf8mb4_general_ci |
| collation_server     | utf8mb4_general_ci |
+----------------------+--------------------+

而且我仍然没有在记录中得到正确的字符（“ç”、“ã”、“á”等）：

+----+----------------------+----------------------------+--------------------------------+----------------+
| id | name                 | email                      | address                        | dataNascimento |
+----+----------------------+----------------------------+--------------------------------+----------------+
| 25 | Conceição          | con@email                  | Rua Conceição, 1             | 2020-10-04     |
+----+----------------------+----------------------------+--------------------------------+----------------

我错过了什么？... :(

标签： javamysqljdbcencodingutf-8

解决方案

尝试将此过滤器添加到您的项目中：

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter("/*")
public class CharacterEncodingFilter implements Filter {

    @Override
    public void init(FilterConfig config) throws ServletException {
        // NOOP.
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("UTF-8");
        filterChain.doFilter(servletRequest, servletResponse);
    }



    @Override
    public void destroy() {
        // NOOP.
    }
}

您可能还需要将此添加到您的 web.xml 文件中

 <filter>
    <filter-name>CharacterEncodingFilter </filter-name>
    <filter-class>your-class-name</filter-class>
      <init-param>
        <param-name>CharacterEncodingFilter </param-name>
        <param-value>UTF-8</param-value>
      </init-param>
  </filter>

  <filter-mapping>
    <filter-name>CharacterEncodingFilter </filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

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