spring-boot使用教程(二)：增加自定义filter

传统的javaEE增加Filter是在web.xml中配置，如以下代码：

<filter>
     <filter-name>TestFilter</filter-name>
        <filter-class>com.cppba.filter.TestFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>TestFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <init-param>
       <param-name>paramName</param-name>
       <param-value>paramValue</param-value>
    </init-param>
</filter-mapping>

然而spring-boot中很明显不能这样实现，那怎么办呢？看完下面的教程，答案自然知道了。

老方法（新方法请直接下拉）

1.创建自定义Filter

package com.cppba.filter;

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

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

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
            throws IOException, ServletException {
        System.out.println("TestFilter");
    }

    @Override
    public void destroy() {

    }
}

2.在ApplicationConfiguration.java中增加一个@bean

 @Bean
    public FilterRegistrationBean testFilterRegistration() {

        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new TestFilter());
        registration.addUrlPatterns("/*");
        registration.addInitParameter("paramName", "paramValue");
        registration.setName("testFilter");
        registration.setOrder(1);
        return registration;
    }

3.启动项目

你会看到控制台打印如下代码：

https://github.com/bigbeef/cppba-spring-boot

4.访问项目

最后我们访问以下http://127.0.0.1:8080/test
如果你看到控制台打印出:TestFilter

https://github.com/bigbeef/cppba-spring-boot
恭喜你，配置成功！

 

2017-04-20 最新spring-boot增加Filter方法

首先定义一个Filter

@Order(1)
//重点
@WebFilter(filterName = "testFilter1", urlPatterns = "/*")
public class TestFilterFirst implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
            throws IOException, ServletException {
        System.out.println("TestFilter1");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

比较核心的代码是自定义类上面加上@WebFilter，其中@Order注解表示执行过滤顺序，值越小，越先执行

我们在spring-boot的入口处加上如下注解@ServletComponentScan：

@SpringBootApplication(scanBasePackages = "com.cppba")
//重点
@ServletComponentScan
public class Application {
    public static void main(String[] args) throws UnknownHostException {
        SpringApplication app = new SpringApplication(Application.class);
        Environment environment = app.run(args).getEnvironment();
    }
}

这种方法效果和上面版本一样，但是用起来更加方便！