springboot 使用过滤器filter

定义filter过滤拦截的path:

@Configuration
public class FilterConfig {

    @Bean
    public FilterRegistrationBean filterRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean(new TestFilter());
        registration.addUrlPatterns("/alarm/*","/order/*","/esee/*");
        registration.setName("testFilter");
        registration.setOrder(1);
        return registration;
    }
}

定义过滤器

public class TestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        Map extraParams = new HashMap();
        extraParams.put("token", httpRequest.getHeader("token"));

        //利用原始的request对象创建自己扩展的request对象并添加自定义参数
        testRequestWrapper testRequestWrapper = new testRequestWrapper(httpRequest);
        testRequestWrapper.addParameters(extraParams);
        filterChain.doFilter(testRequestWrapper, response);
    }

    @Override
    public void destroy() {
    }
}

定义wrapper

public class TestRequestWrapper extends HttpServletRequestWrapper {

    private Map params = new HashMap();

    public TestRequestWrapper(HttpServletRequest request) {
        super(request);
        //将现有parameter传递给params
        this.params.putAll(request.getParameterMap());
    }

    /**
     * 重载构造函数
     * @param request
     * @param extraParams
     */
    public TestRequestWrapper(HttpServletRequest request, Map extraParams) {
        this(request);
        addParameters(extraParams);
    }

    public void addParameters(Map extraParams) {
        for (Map.Entry entry : extraParams.entrySet()) {
            addParameter(entry.getKey(), entry.getValue());
        }
    }

    /**
     * 重写getParameter，代表参数从当前类中的map获取
     * @param name
     * @return
     */
    @Override
    public String getParameter(String name) {
        String[]values = params.get(name);
        if(values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }

    /**
     * 同上
     * @param name
     * @return
     */
    @Override
    public String[] getParameterValues(String name) {
        return params.get(name);
    }

    /**
     * 添加参数
     * @param name
     * @param value
     */
    public void addParameter(String name, Object value) {
        if (value != null) {
            System.out.println(value);
            if (value instanceof String[]) {
                params.put(name, (String[]) value);
            } else if (value instanceof String) {
                params.put(name, new String[]{(String) value});
            } else {
                params.put(name, new String[]{String.valueOf(value)});
            }
        }
    }
}