今天在项目中获取request的请求数据为空,消耗了一天的时间
百度了两篇文章解决了这个问题:原因 解决方案
- 阐述下问题:
项目是记录请求数据及响应数据,但在获取请求数据时使用request.getInputStream()为空,而使用
Enumeration enu=request.getParameterNames();
while(enu.hasMoreElements()){
String paraName=(String)enu.nextElement();
System.out.println(paraName+": "+request.getParameter(paraName));
}
但是获取的值是不完整的,它将原数据前面部分作为参数key,后面部分作为参数value。
- 分析原因
经过一顿操作,发现客户端上送的Content-Type的值为 这里可以看下
application/x-www-form-urlencoded;charset=UTF-8
而不是
text/xml
text/plain
application/json
所以请求数据的值是以key/value形式存储的。
若在使用request.getInputStream()前已经使用过getParameter或者@requestParam注解方式,则request.getInputStream()获取为空。
3 解决方案
1 将post请求的Content-Type 设置为text/xml
2 通过遍历获取所有参数,再获取参数值
3 避免在request.getInputStream()之前使用getParameter或者@requestParam注解方式
4 对httprequest进行修饰
定义InputStreamHttpServletRequestWrapper类继承于HttpServletRequestWrapper对请求数据进行处理
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.stream.Collectors;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import org.springframework.web.bind.annotation.RequestMethod;
public class InputStreamHttpServletRequestWrapper extends HttpServletRequestWrapper{
private final byte[] streamBody;
private static final int BUFFER_SIZE = 4096;
//对请求数据判断,getInputStream()为空的数据对key和value值进行拼接
public InputStreamHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
byte[] bytes = inputStream2Byte(request.getInputStream());
if (bytes.length == 0 && RequestMethod.POST.name().equals(request.getMethod())) {
//从ParameterMap获取参数,并保存以便多次获取
bytes = request.getParameterMap().entrySet().stream()
.map(entry -> {
String result;
String[] value = entry.getValue();
if (value != null && value.length > 1) {
result = Arrays.stream(value).map(s -> entry.getKey() + "=" + s)
.collect(Collectors.joining("&"));
} else {
result = entry.getKey() + "=" + value[0];
}
return result;
}).collect(Collectors.joining("&")).getBytes();
}
//System.err.println(new String(bytes));
streamBody = bytes;
}
private byte[] inputStream2Byte(InputStream inputStream) throws IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] bytes = new byte[BUFFER_SIZE];
int length;
while ((length = inputStream.read(bytes, 0, BUFFER_SIZE)) != -1) {
outputStream.write(bytes, 0, length);
}
return outputStream.toByteArray();
}
@Override
public ServletInputStream getInputStream() throws IOException {
ByteArrayInputStream inputStream = new ByteArrayInputStream(streamBody);
return new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener listener) {
}
@Override
public int read() throws IOException {
return inputStream.read();
}
};
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(getInputStream()));
}
}
写doFilterInternal类对InputStreamHttpServletRequestWrapper 进行调用即过滤器对请求的处理,该类继承于OncePerRequestFilter,一次请求只调用一次
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.filter.OncePerRequestFilter;
public class InputStreamWrapperFilter extends OncePerRequestFilter{
@Override
protected void doFilterInternal(HttpServletRequest httpServletRequest,
HttpServletResponse httpServletResponse, FilterChain filterChain) throws ServletException, IOException {
ServletRequest servletRequest = new InputStreamHttpServletRequestWrapper(httpServletRequest);
filterChain.doFilter(servletRequest, httpServletResponse);
}
}
最后确定过滤器调用的顺序
在application类中
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.embedded.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.core.annotation.Order;
import com.springboot.SpringBootUtill.InputStreamWrapperFilter;
@SpringBootApplication
@Slf4j
public class Application
{
public static void main(String[] args)
{
log.info("=================开始成功=================");
SpringApplication.run(Application.class, args);
log.info("=================启动成功=================");
}
@Bean
@Order(1)
public FilterRegistrationBean inputStreamWrapperFilterRegistration() {
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
registrationBean.setFilter(new InputStreamWrapperFilter());
registrationBean.setName("inputStreamWrapperFilter");
registrationBean.addUrlPatterns("/*");
return registrationBean;
}
}
到此为止该问题已经解决了,可以获取到参数了
//获取请求body
String getRequestMsg(HttpServletRequest request) throws IOException {
BufferedReader br = request.getReader();
String str, wholeStr = "";
while((str = br.readLine()) != null){
wholeStr += str;
}
return wholeStr;
}
现在还有个疑问,我并没有在request.getInputStream()前使用过getParameter或者@requestParam注解方式。是不是springboot在嵌入tomcat后,请求自动调用了getParameter方法呢。