springmvc项目中使用过滤器来解决请求方式为post时出现乱码的问题

在spring项目中，当请求方式为post时，可能在获取数据之后会有乱码的情况，其中一种解决方法就是在拿到请求参数之前设置编码格式为utf-8，如下

        request.setCharacterEncoding("utf-8");
        String strId = request.getParameter("id");
        String strName = request.getParameter("name");
        String strSex = request.getParameter("sex");

但是当有多个处理器方法的时候每个方法中都要设置编码格式就显得过于繁琐，所以推荐第二种解决方案：使用过滤器

只要在web.xml中对过滤器进行声明注册就可以了

    
        characterEncodingFilter
        org.springframework.web.filter.CharacterEncodingFilter

        
            encoding
            utf-8
        

        
            forceRequestEncoding
            true
        

        
            forceResponseEncoding
            true
        
    

    

        characterEncodingFilter
        /*
    

另外，我们可以看一下CharacterEncodingFilter的实现方法的实现就知道为什么要设置后边的encoding，forceRequestEncoding，forceResponseEncoding这三个参数了，因为这三个参数是这个方法中的是三个私有属性

public class CharacterEncodingFilter extends OncePerRequestFilter {
    @Nullable
    private String encoding;
    private boolean forceRequestEncoding;
    private boolean forceResponseEncoding;

    public CharacterEncodingFilter() {
        this.forceRequestEncoding = false;
        this.forceResponseEncoding = false;
    }

    public CharacterEncodingFilter(String encoding) {
        this(encoding, false);
    }

    public CharacterEncodingFilter(String encoding, boolean forceEncoding) {
        this(encoding, forceEncoding, forceEncoding);
    }

    public CharacterEncodingFilter(String encoding, boolean forceRequestEncoding, boolean forceResponseEncoding) {
        this.forceRequestEncoding = false;
        this.forceResponseEncoding = false;
        Assert.hasLength(encoding, "Encoding must not be empty");
        this.encoding = encoding;
        this.forceRequestEncoding = forceRequestEncoding;
        this.forceResponseEncoding = forceResponseEncoding;
    }