包结构
paramsfilter.png
- 创建ParamsFilter实现Filter接口
package com.example.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/**
* @author chengdongyi
* @description: 请求参数过滤器
* @date 2019/7/1 10:33
*/
public class ParamsFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
ParamsRequestWrapper requestWrapper = new ParamsRequestWrapper(httpRequest);
filterChain.doFilter(requestWrapper, servletResponse);
}
@Override
public void destroy() {
}
}
- 过滤请求参数
package com.example.filter;
import com.alibaba.fastjson.JSON;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* @author chengdongyi
* @description: 对请求参数进行过滤
* @date 2019/7/1 11:02
*/
public class ParamsRequestWrapper extends HttpServletRequestWrapper {
private Map<String, String[]> params = new HashMap<>();
private static final String ENCODING = "UTF-8";
private static final String CLASSTYPE = "java.lang.String";
public ParamsRequestWrapper(HttpServletRequest request) {
super(request);
// 将参数表，赋予给当前的Map以便于持有request中的参数
Map<String, String[]> requestMap = request.getParameterMap();
System.out.println("转化前参数：" + JSON.toJSONString(requestMap));
this.params.putAll(requestMap);
this.modifyParameters();
System.out.println("转化后参数：" + JSON.toJSONString(params));
}
/**
* 重写getInputStream方法 post请求参数必须通过流才能获取到值
*/
@Override
public ServletInputStream getInputStream() throws IOException {
ServletInputStream stream = super.getInputStream();
//非json类型，直接返回
if (!super.getHeader(HttpHeaders.CONTENT_TYPE).equalsIgnoreCase(MediaType.APPLICATION_JSON_VALUE)) {
return stream;
}
String json = IOUtils.toString(stream, ENCODING);
if (StringUtils.isBlank(json)) {
return stream;
}
System.out.println("转化前参数：" + json);
Map<String, Object> map = modifyParams(json);
System.out.println("转化后参数：" + JSON.toJSONString(map));
ByteArrayInputStream bis = new ByteArrayInputStream(JSON.toJSONString(map).getBytes(ENCODING));
return new ParamsServletInputStream(bis);
}
private static Map<String, Object> modifyParams(String json) {
Map<String, Object> params = JSON.parseObject(json);
Map<String, Object> maps = new HashMap<>(params.size());
for (String key : params.keySet()) {
Object value = getValue(params.get(key));
maps.put(key, value);
}
return maps;
}
private static Object getValue(Object obj) {
if (obj == null) {
return null;
}
String type = obj.getClass().getName();
// 对字符串的处理
if (CLASSTYPE.equals(type)) {
obj = obj.toString().trim();
}
return obj;
}
/**
* 将parameter的值去除空格后重写回去
*/
private void modifyParameters() {
Set<String> set = params.keySet();
Iterator<String> it = set.iterator();
while (it.hasNext()) {
String key = (String) it.next();
String[] values = params.get(key);
values[0] = values[0].trim();
params.put(key, values);
}
}
/**
* 重写getParameter 参数从当前类中的map获取
*/
@Override
public String getParameter(String name) {
String[] values = params.get(name);
if (values == null || values.length == 0) {
return null;
}
return values[0];
}
}
- 字节数据转换流（Map → ByteArrayInputStream → ServletInputStream ）
package com.example.filter;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
/**
* @author chengdongyi
* @description: 请求参数输入流
* @date 2019/7/1 10:46
*/
public class ParamsServletInputStream extends ServletInputStream {
private ByteArrayInputStream bis;
public ParamsServletInputStream(ByteArrayInputStream bis) {
this.bis = bis;
}
@Override
public boolean isFinished() {
return true;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return bis.read();
}
}
- 过滤器配置类
package com.example.config;
import com.example.filter.ParamsFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.DispatcherType;
/**
* @description: 过滤器配置类
* @author chengdongyi
* @date 2019/7/1 10:31
*/
@Configuration
public class FilterConfig {
@Bean
public FilterRegistrationBean parmsFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setDispatcherTypes(DispatcherType.REQUEST);
registration.setFilter(new ParamsFilter());
registration.addUrlPatterns("/*");
registration.setName("ParamsFilter");
registration.setOrder(Integer.MAX_VALUE - 1);
return registration;
}
}
过滤器过滤的请求为所有请求(/*)，排除部分请求
- 在配置类中添加不需要过滤的请求的url
package com.example.config;
import com.example.filter.ParamsFilter;
import org.apache.commons.lang3.StringUtils;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.DispatcherType;
import java.util.HashSet;
import java.util.Set;
/**
* @description: 过滤器配置类
* @author chengdongyi
* @date 2019/7/1 10:31
*/
@Configuration
public class FilterConfig {
@Bean
public FilterRegistrationBean parmsFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setDispatcherTypes(DispatcherType.REQUEST);
registration.setFilter(new ParamsFilter());
registration.addUrlPatterns("/*");
// 排除不需要过滤的请求
Set<String> set = new HashSet<>();
set.add("/hello");
set.add("/testFilter");
String urls = StringUtils.join(set.toArray(), ",");
registration.addInitParameter("exclusions", urls);
registration.setName("ParamsFilter");
registration.setOrder(Integer.MAX_VALUE - 1);
return registration;
}
}
package com.example.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
/**
* @author chengdongyi
* @description: 请求参数过滤器
* @date 2019/7/1 10:33
*/
public class ParamsFilter implements Filter {
public static final String PARAM_NAME_EXCLUSIONS = "exclusions";
public static final String SEPARATOR = ",";
private Set<String> excludesUrls;
@Override
public void init(FilterConfig filterConfig) throws ServletException {
String param = filterConfig.getInitParameter(PARAM_NAME_EXCLUSIONS);
if (param != null && param.trim().length() != 0) {
this.excludesUrls = new HashSet(Arrays.asList(param.split(SEPARATOR)));
}
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
String requestURI = httpRequest.getRequestURI();
if (this.isExclusion(requestURI)) {
// 不过滤
filterChain.doFilter(servletRequest, servletResponse);
} else {
// 过滤
ParamsRequestWrapper requestWrapper = new ParamsRequestWrapper(httpRequest);
filterChain.doFilter(requestWrapper, servletResponse);
}
}
@Override
public void destroy() {
}
public boolean isExclusion(String requestURI) {
if (this.excludesUrls == null) {
return false;
}
for (String url : this.excludesUrls) {
if (url.equals(requestURI)) {
return true;
}
}
return false;
}
}
