java后台乱码怎么办

//将乱码字符串按照错误的编码方式转换为原始的字符串序列
byte[] bs = 乱码字段.getBytes("ISO8859-1");
//将原始的字符串序列按照正确的编码转换为正确的文字即可
新字段 = new String(bs,"UTF-8");

<!--编码过滤器 -->
    <filter>
        <description>字符集过滤器</description>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <description>字符集编码</description>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <!-- 路径映射 -->
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>