springboot清除字符串前后空格与防xss攻击方法

springboot清除字符串前后空格与防xss攻击

一、查看WebMvcAutoConfiguration.class中的方法源码

protected ConfigurableWebBindingInitializer getConfigurableWebBindingInitializer() {
    try {
        //从容器中获取
        return (ConfigurableWebBindingInitializer)this.beanFactory.getBean(ConfigurableWebBindingInitializer.class);
    } catch (NoSuchBeanDefinitionException ex) {
      return super.getConfigurableWebBindingInitializer();
    }

可以发现ConfigurableWebBindingInitializer是从容器（beanFactory）中获取到的，所以我们可以配置一个

ConfigurableWebBindingInitializer来替换默认的，只需要在容器中添加一个我们自定义的转换器即可。

当我们创建了自己的ConfigurableWebBindingInitializer这个Bean，Spring boot就会自动使用它来配置Spring MVC实现参数的类型转换。

二、自定义属性编辑器

/**
     *
     * @description 与spring mvc的@InitBinder结合 用于防止XSS攻击
     */
     class StringEscapeEditor extends PropertyEditorSupport {
        /** 转义HTML */
        private boolean escapeHTML;
        /** 转义javascript */
        private boolean escapeJavaScript;
        /** 是否将空字符串转换为null */
        private final boolean emptyAsNull;
        /** 是否去掉前后空格 */
        private final boolean trimmed;
        public StringEscapeEditor() {
            this(true,true,false,true);
        }
        public StringEscapeEditor(boolean escapeHTML, boolean escapeJavaScript) {
            this(true,true,escapeHTML,escapeJavaScript);
        }
        public StringEscapeEditor(boolean emptyAsNull,boolean trimmed, boolean escapeHTML, boolean escapeJavaScript) {
            super();
            this.emptyAsNull = emptyAsNull;
            this.trimmed = trimmed;
            this.escapeHTML = escapeHTML;
            this.escapeJavaScript = escapeJavaScript;
        }
        @Override
        public String getAsText() {
            Object value = getValue();
            if(Objects.nonNull(value))
            {
                return value.toString();
            }
            return value != null ? value.toString() : null;
        }
        @Override
        public void setAsText(String text) throws IllegalArgumentException {
            String value = text;
            if (value == null || emptyAsNull && text.isEmpty()) {
                //do nothing
            } else if (trimmed) {
                //去字符传参数前后空格
                value = value.trim();
            }
            if (escapeHTML) {
                //HTML转义（防止XSS攻击）
                //HtmlUtils.htmlEscape 默认的是ISO-8859-1编码格式，会将中文的某些符号进行转义。
                //如果不想让中文符号进行转义请使用UTF-8的编码格式。例如：HtmlUtils.htmlEscape(text, "UTF-8")
                value = HtmlUtils.htmlEscape(value, "UTF-8");
            }
            if (escapeJavaScript) {
                //javascript转义（防止XSS攻击）
                value = JavaScriptUtils.javaScriptEscape(value);
            }
            setValue(value);
        }
    }

三、创建WebBindingInitializerConfiguration类

加上@Bean注解，交给spring容器管理。

@Configuration
public class WebBindingInitializerConfiguration {
    @Bean
    public ConfigurableWebBindingInitializer getConfigurableWebBindingInitializer() {
        ConfigurableWebBindingInitializer initializer = new ConfigurableWebBindingInitializer();
        FormattingConversionService conversionService = new DefaultFormattingConversionService();
        //we can add our custom converters and formatters
        //conversionService.addConverter(...);
        //conversionService.addFormatter(...);
        initializer.setConversionService(conversionService);
        //we can set our custom validator
        //initializer.setValidator(....);
        //here we are setting a custom PropertyEditor
        initializer.setPropertyEditorRegistrar(propertyEditorRegistry -> {
            propertyEditorRegistry.registerCustomEditor(String.class,
                    new StringEscapeEditor());
        });
        return initializer;
    }
}

springboot去除参数中前后空格说明

一、 需求

使用SpringBoot使用过滤器去除@RequestBody参数两端的空格；一般我们去普通的请求我们都会对请求参数进行验证。

Java也提供了@notNull和@notBlank这种验证方式，但是对@RequestBody 这种只能验证是不是非空，对数据两端的空格未进行处理，同时大家也不想遍历一遍参数然后再处理再封装到对象中，正好项目中有这个需要，所以就参考别的做了Post请求中针对application/json格式的有@RequestBody注解的参数进行了去空格处理

二、 解决方法

2.1 新建一个过滤器

@Component
@WebFilter(urlPatterns = "/**", filterName = "ParamsFilter", dispatcherTypes = DispatcherType.REQUEST)
public class ParamsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        ParameterRequestWrapper parmsRequest = new ParameterRequestWrapper((HttpServletRequest) request);
        chain.doFilter(parmsRequest, response);
    }
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void destroy() {
    }
}

2.2 实现ParameterRequestWrapper

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import com.alibaba.fastjson.JSON;
/**
 * @author : 
 * @description
 * @date : 2021/4/22
 */
public class ParameterRequestWrapper extends HttpServletRequestWrapper {
    private Map<String , String[]> params = new HashMap<>();
    public ParameterRequestWrapper(HttpServletRequest request) {
        super(request);
        Map<String, String[]> requestMap=request.getParameterMap();
        this.params.putAll(requestMap);
        this.modifyParameterValues();
    }
    @Override
    public ServletInputStream getInputStream() throws IOException {
        if(!super.getHeader(HttpHeaders.CONTENT_TYPE).equalsIgnoreCase(MediaType.APPLICATION_JSON_VALUE)){
            return super.getInputStream();
        }
        String json = IOUtils.toString(super.getInputStream(), "utf-8");
        if (StringUtils.isEmpty(json)) {
            return super.getInputStream();
        }
        Map<String,Object> map= jsonStringToMap(json);
        ByteArrayInputStream bis = new ByteArrayInputStream(JSON.toJSONString(map).getBytes("utf-8"));
        return new MyServletInputStream(bis);
    }
    public void modifyParameterValues(){
        Set<String> set = params.keySet();
        Iterator<String> it = set.iterator();
        while(it.hasNext()){
            String key= it.next();
            String[] values = params.get(key);
            values[0] = values[0].trim();
            params.put(key, values);
        }
    }
    @Override
    public String getParameter(String name) {
        String[]values = params.get(name);
        if(values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }
    @Override
    public String[] getParameterValues(String name) {
        return params.get(name);
    }
    class MyServletInputStream extends ServletInputStream {
        private ByteArrayInputStream bis;
        public MyServletInputStream(ByteArrayInputStream bis){
            this.bis=bis;
        }
        @Override
        public boolean isFinished() {
            return true;
        }
        @Override
        public boolean isReady() {
            return true;
        }
        @Override
        public void setReadListener(ReadListener listener) {
        }
        @Override
        public int read(){
            return bis.read();
        }
    }
    public static Map<String, Object> jsonStringToMap(String jsonString) {
        Map<String, Object> map = new HashMap<>();
        JSONObject jsonObject = JSONObject.parseObject(jsonString);
        for (Object k : jsonObject.keySet()) {
            Object o = jsonObject.get(k);
            if (o instanceof JSONArray) {
                List<Map<String, Object>> list = new ArrayList<>();
                Iterator<Object> it = ((JSONArray) o).iterator();
                while (it.hasNext()) {
                    Object obj = it.next();
                    list.add(jsonStringToMap(obj.toString()));
                }
                map.put(k.toString(), list);
            } else if (o instanceof JSONObject) {
                map.put(k.toString(), jsonStringToMap(o.toString()));
            } else {
                if (o instanceof String) {
                    map.put(k.toString(), o.toString().trim());
                } else {
                    map.put(k.toString(), o);
                }
            }
        }
        return map;
    }
}

三、 完美解决

参数前后空格完美去除！

以上为个人经验，希望能给大家一个参考，也希望大家多多支持猪先飞。