jQuery.Ajax回调函数success返回字符串中文乱码问题

$.post请求到 /a3 成功后获取返回的中文字符串 data 结果在浏览器输出 出现乱码

js代码

$('#update-button').on('click',function () {
        var stuID = $('#stuID').val();
        var num = $('#rf_num').val();
        var password = $('#rf_password').val();
        var realName = $('#rf_name').val();
        var college = $('#rf_college').val();
        var grade = $('#rf_grade').val();
        var profession = $('#rf_profession').val();
        var classNum = $('#rf_class').val();
        var tel = $('#rf_tel').val();
        $.ajax({
            type:"POST",
            url:getRootPath()+"/manager/updateStudent.action",
            data:{
                stuId:stuID,
                num:num,
                password:password,
                realName:realName,
                college:college,
                grade:grade,
                profession:profession,
                classNum:classNum,
                tel:tel
            },
            success: function (data) {
                alert(data);
                console.log(data);
            }
        });
    });

java 代码

@RequestMapping("updateStudent")
    @ResponseBody
    public String updateStudent(Integer stuId, String num, String password, String realName, String college, String grade,
                                String profession, String classNum, String tel){
        //先改学生信息
        Sstudent student = studentService.getStudentById(stuId);
        student.setRealName(realName);
        student.setStuGrade(grade);
        student.setStuClass(classNum);
        student.setStuPhone(tel);
        //获取所有专业匹配一下
        List<Professional> professionalList = professionalService.selectAll();
        for (Professional professional : professionalList) {
            if (professional.getProfessionalName().equals(profession)){
                student.setProfessionalId(professional.getProfessionalId());
                student.setStuCollegeId(professional.getCollegeId());
                break;
            }
        }
        //User信息
        Uuser user = userService.getUserById(stuId);
        user.setUsername(num);
        user.setPassword(password);

        //更改两个表 1.学生表 2.user表
        studentService.updateStudent(student);
        userService.updateUser(user);
        return "修改成功";

解决方法：在web.xml配置文件中加入spring的filter过滤器

  <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

如果在web.xml中加入spring编码过滤器还是无效，就在springmvc-servlet.xml配置文件中加入以下代码

<!--支持mvc注解-->
    <mvc:annotation-driven>
        <!--    json乱码解决-->
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

加入之后就成功解决