spring-boot过滤器篇
本文记录在spring-boot环境下，添加配置过滤器。以及过滤器的一些常见使用……
在spring-boot项目中添加过滤器
方式一
1.创建类TestFilter,并实现Filter接口
package com.ymu.servicecommon.filter;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import javax.servlet.*;
import java.io.IOException;
/**
* 功能简述:<br>
* 过滤器配置测试。
*
* @author zmt
* @create 2018-04-26 下午5:15
* @updateTime
* @since 1.0.0
*/
public class TestFilter implements Filter {
protected final Logger logger = LogManager.getLogger(this.getClass());
@Override
public void init(FilterConfig filterConfig) throws ServletException {
logger.debug(">>>>testFilter init");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
logger.debug(">>>>testFilter doFilter");
filterChain.doFilter(servletRequest,servletResponse);
}
@Override
public void destroy() {
logger.debug(">>>>testFilter destroy");
}
}
2.注解bean
package com.ymu.servicecommon.config;
import com.ymu.servicecommon.filter.TestFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MainConfig {
/**
* 配置过滤器
* @return
*/
@Bean
public FilterRegistrationBean indexFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean(new TestFilter());
registration.addUrlPatterns("/*");
// registration.addInitParameter("abc", "abc-value");
registration.setName("testFilter");
return registration;
}
}
方式二
1.创建过滤器IndexFilter2
package com.example.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
@WebFilter(urlPatterns = "/*", filterName = "indexFilter2")
public class IndexFilter2 implements Filter{
@Override
public void destroy() {
System.out.println("filter2 destroy method");
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
System.out.println("filter2 doFilter method");
}
@Override
public void init(FilterConfig arg0) throws ServletException {
System.out.println("filter2 init method");
}
}
2.在程序启动入库加入注解ServletComponentScan
@SpringBootApplication
@ServletComponentScan
public class SpringBootSimpleApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootSimpleApplication.class, args);
}
}
多个过滤器调用顺序
在spring-boot中通过注解@Order来标识。这个order的默认值是Integer.MAX_VALUE 也就是int的最大值。多个过滤器会按照order属性的大小从小到大执行。
1.代码设置
package com.ymu.servicecommon.config;
import com.ymu.servicecommon.filter.Test2Filter;
import com.ymu.servicecommon.filter.TestFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MainConfig {
/**
* 配置过滤器
* @return
*/
@Bean
public FilterRegistrationBean testFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean(new TestFilter());
registration.addUrlPatterns("/*");
// registration.addInitParameter("abc", "abc-value");
registration.setName("testFilter");
registration.setOrder(Integer.MAX_VALUE); //设置过滤器执行先后顺序，多个按从小到大执行
return registration;
}
@Bean
public FilterRegistrationBean test2FilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean(new Test2Filter());
registration.addUrlPatterns("/*");
// registration.addInitParameter("abc", "abc-value");
registration.setName("test2Filter");
registration.setOrder(Integer.MAX_VALUE-1); //设置过滤器执行先后顺序，多个按从小到大执行
return registration;
}
}
- 启动程序，观察执行顺序。
- 请求接口，观察执行顺序。
在过滤器中为请求添加http请求头信息
1.定义类ModifyHttpServletRequestWrapper.java
package com.ymu.framework.web;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.*;
public class ModifyHttpServletRequestWrapper extends HttpServletRequestWrapper {
private Map<String, String> customHeaders;
public ModifyHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
this.customHeaders = new HashMap<>();
}
public void putHeader(String name, String value) {
this.customHeaders.put(name, value);
}
public String getHeader(String name) {
String value = this.customHeaders.get(name);
if (value != null) {
return value;
}
return ((HttpServletRequest) getRequest()).getHeader(name);
}
public Enumeration<String> getHeaderNames() {
Set<String> set = new HashSet<>(customHeaders.keySet());
Enumeration<String> enumeration = ((HttpServletRequest) getRequest()).getHeaderNames();
while (enumeration.hasMoreElements()) {
String name = enumeration.nextElement();
set.add(name);
}
return Collections.enumeration(set);
}
}
2.定义过滤器，编辑
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
logger.debug(">>>>indexFilter doFilter");
//添加或者更改header信息
HttpServletRequest request = (HttpServletRequest) servletRequest;
String apiVersion = request.getHeader("Content-Version");
if (null == apiVersion || "".equals(apiVersion)) {
ModifyHttpServletRequestWrapper requestWrapper = new ModifyHttpServletRequestWrapper(request);
requestWrapper.putHeader("Content-Version","-1");
filterChain.doFilter(requestWrapper,servletResponse);
} else {
filterChain.doFilter(request,servletResponse);
}
}
重点代码：
ModifyHttpServletRequestWrapper requestWrapper = new ModifyHttpServletRequestWrapper(request);
requestWrapper.putHeader("Content-Version","-1");
filterChain.doFilter(requestWrapper,servletResponse);