目录
目的
在Springboot中创建过滤器，用来过滤所有POST类型请求并获取body中的参数进行校验内容是否合法；该方法仅适用于POST类型请求，因为POST和GET请求的参数位置不一样所以处理方式也不一样，如果想要实现拦截获取GET类型请求校验参数，可以参考以下示例：
https://blog.csdn.net/weixin_45151960/article/details/132184917?spm=1001.2014.3001.5501实现步骤
1、创建Filter过滤器用来过滤所有请求；
2、将PSOT类型请求中的body参数内容进行转换；
3、处理body数据进行校验：
3.1、当body数据仅为json对象时进行处理校验；
3.2、当body数据仅为json数组时进行处理校验；
3.3、当body数据为json对象且包含json数组时进行处理校验；
3.4、当body数据为json数组且包含json对象时进行处理校验；
完整代码
过滤器
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.boc.ljh.utils.Result;
import com.boc.ljh.utils.status.AppErrorCode;
import org.springframework.context.annotation.Configuration;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* @Author: ljh
* @ClassName SqlFilter
* @Description 过滤请求内容 防止sql注入
* @date 2023/8/8 16:15
* @Version 1.0
*/
@WebFilter(urlPatterns = "/*", filterName = "sqlFilter")
@Configuration
public class SqlFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) servletResponse;
response.setContentType("application/json;charset=utf-8");
Result result = new Result();
result.setStatus(500);
result.setMessage(AppErrorCode.REQUEST_DATA_FULL.message);
String data = JSON.toJSONString(result);
BodyReaderRequestWrapper wrapper = null;
HttpServletRequest request = (HttpServletRequest) servletRequest;
if (request.getMethod().equals("POST")) {
String contentType = request.getContentType();
if ("application/json".equals(contentType)) {
wrapper = new BodyReaderRequestWrapper(request);
String requestPostStr = wrapper.getBody();
if (requestPostStr.startsWith("{")) {
//解析json对象
boolean b = resolveJSONObjectObj(requestPostStr);
if (!b) {
response.getWriter().print(data);
return;
}
} else if (requestPostStr.startsWith("[")) {
//把数据转换成json数组
JSONArray jsonArray = JSONArray.parseArray(requestPostStr);
List<String> list = JSONObject.parseArray(jsonArray.toJSONString(), String.class);
for (String str : list) {
if (str.startsWith("{")) {
//解析json对象
boolean b = resolveJSONObjectObj(requestPostStr);
if (!b) {
response.getWriter().print(data);
return;
}
} else {
boolean b = verifySql(str);
if (b) {
try {
response.getWriter().print(data);
return;
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
} else {
//application/x-www-form-urlencoded
Map<String, String[]> parameterMap = request.getParameterMap();
for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
//校验参数值是否合法
String[] value = entry.getValue();
for (String s : value) {
//校验参数值是否合法
boolean b = verifySql(s);
if (b) {
response.getWriter().print(data);
return;
}
}
}
}
}
if (wrapper == null) {
filterChain.doFilter(servletRequest, servletResponse);
} else {
filterChain.doFilter(wrapper, servletResponse);
}
}
/**
* @Author: ljh
* @Description: 对JSONObject对象进行递归参数解析
* @DateTime: 14:26 2023/8/9
* @Params:
* @Return
*/
private boolean resolveJSONObjectObj(String requestPostStr) {
boolean isover = true;
// 创建需要处理的json对象
JSONObject jsonObject = JSONObject.parseObject(requestPostStr);
// 获取所有的参数key
Set<String> keys = jsonObject.keySet();
if (keys.size() > 0) {
for (String key : keys) {
//获取参数名称
String value;
if (jsonObject.get(key) != null) {
value = String.valueOf(jsonObject.get(key));
//当value为数组时
if (value.startsWith("[")) {
//把数据转换成json数组
JSONArray jsonArray = JSONArray.parseArray(value);
for (Object o : jsonArray) {
if (o.toString().startsWith("{")) {
//解析json对象
boolean b = resolveJSONObjectObj(o.toString());
if (!b) {
isover = false;
break;
}
} else {
boolean b = verifySql(value);
if (b) {
isover = false;
break;
}
}
}
} else if (value.startsWith("{")) {
boolean b = resolveJSONObjectObj(value);
if (!b) {
isover = false;
break;
}
} else {
//校验参数值是否合法
boolean b = verifySql(value);
if (b) {
isover = false;
break;
}
}
}
}
}
return isover;
}
@Override
public void destroy() {
}
/**
* @Author: ljh
* @Description: 校验参数非法字符
* @DateTime: 14:26 2023/8/9
* @Params:
* @Return
*/
public boolean verifySql(String parameter) {
String s = parameter.toLowerCase();
// 过滤掉的sql关键字，特殊字符前面需要加\\进行转义
String badStr =
"select|update|and|or|delete|insert|truncate|char|into|substr|ascii|declare|exec|count|master|into|drop|execute|table|" +
"char|declare|sitename|xp_cmdshell|like|from|grant|use|group_concat|column_name|" +
"information_schema.columns|table_schema|union|where|order|by|" +
"'\\*|\\;|\\-|\\--|\\+|\\,|\\//|\\/|\\%|\\#";
//使用正则表达式进行匹配
boolean matches = s.matches(badStr);
return matches;
}
}解析body数据 工具类
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
/**
* @Author: ljh
* @ClassName BodyReaderRequestWrapper
* @Description 解析body数据
* @date 2023/8/8 16:14
* @Version 1.0
*/
public class BodyReaderRequestWrapper extends HttpServletRequestWrapper {
private final String body;
public String getBody() {
return body;
}
/**
* 取出请求体body中的参数（创建对象时执行）
*
* @param request
*/
public BodyReaderRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
StringBuilder sb = new StringBuilder();
InputStream ins = request.getInputStream();
BufferedReader isr = null;
try {
if (ins != null) {
isr = new BufferedReader(new InputStreamReader(ins));
char[] charBuffer = new char[128];
int readCount;
while ((readCount = isr.read(charBuffer)) != -1) {
sb.append(charBuffer, 0, readCount);
}
}
} finally {
if (isr != null) {
isr.close();
}
}
sb.toString();
body = sb.toString();
}
@Override
public BufferedReader getReader() {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
@Override
public ServletInputStream getInputStream() {
final ByteArrayInputStream byteArrayIns = new ByteArrayInputStream(body.getBytes());
return new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() {
return byteArrayIns.read();
}
};
}
}