功能描述
在SpringBoot中如要实现记录接口被调用的频率和生成api日志，以便查看接口使用情况，那么监听所有api请求的功能就诞生了。
功能实现
一、自定义request继承HttpServletRequestWrapper
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import com.alibaba.fastjson.JSONObject;
public class MyRequestWrapper extends HttpServletRequestWrapper {
private byte[] body;
private ServletInputStreamWrapper inputStreamWrapper;
private Object requestBody;
public MyRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
int le = request.getContentLength();
if (le > 0) {
body = new byte[le];
request.getInputStream().read(body);
requestBody = JSONObject.parse(body, 0, body.length, Charset.forName("UTF-8").newDecoder(), 0);
} else {
body = new byte[0];
requestBody = "";
}
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(this.body);
this.inputStreamWrapper = new ServletInputStreamWrapper(byteArrayInputStream);
resetInputStream();
}
public String getRequestBody() {
return String.valueOf(requestBody);
}
public void setRequestBody(Object requestBody) {
this.requestBody = requestBody;
}
private void resetInputStream() {
this.inputStreamWrapper.setInputStream(new ByteArrayInputStream(this.body != null ? this.body : new byte[0]));
}
@Override
public ServletInputStream getInputStream() throws IOException {
return this.inputStreamWrapper;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.inputStreamWrapper));
}
private static class ServletInputStreamWrapper extends ServletInputStream {
private InputStream inputStream;
public ServletInputStreamWrapper(InputStream inputStream) {
super();
this.inputStream = inputStream;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
@Override
public boolean isFinished() {
return true;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return this.inputStream.read();
}
}
}
二、自定义response继承HttpServletResponseWrapper
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.nio.charset.Charset;
import javax.servlet.ServletOutputStream;
import javax.servlet.WriteListener;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import com.alibaba.fastjson.JSONObject;
public class MyResponseWrapper extends HttpServletResponseWrapper {
private ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
private HttpServletResponse response;
private Object reponseBody;
public MyResponseWrapper(HttpServletResponse response) {
super(response);
this.response = response;
}
public String getResponseBody() {
byte[] bytes = byteArrayOutputStream.toByteArray();
reponseBody = JSONObject.parse(bytes, 0, bytes.length, Charset.forName("UTF-8").newDecoder(), 0);
return String.valueOf(reponseBody);
}
@Override
public ServletOutputStream getOutputStream() {
return new ServletOutputStreamWrapper(this.byteArrayOutputStream, this.response);
}
@Override
public PrintWriter getWriter() throws IOException {
return new PrintWriter(
new OutputStreamWriter(this.byteArrayOutputStream, this.response.getCharacterEncoding()));
}
private static class ServletOutputStreamWrapper extends ServletOutputStream {
private ByteArrayOutputStream outputStream;
private HttpServletResponse response;
public ServletOutputStreamWrapper(ByteArrayOutputStream outputStream, HttpServletResponse response) {
this.outputStream = outputStream;
this.response = response;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setWriteListener(WriteListener listener) {
}
@Override
public void write(int b) throws IOException {
this.outputStream.write(b);
}
@Override
public void flush() throws IOException {
if (!this.response.isCommitted()) {
byte[] body = this.outputStream.toByteArray();
ServletOutputStream outputStream = this.response.getOutputStream();
outputStream.write(body);
outputStream.flush();
}
}
}
三、新建一个类RequestWrapperFilter继承OncePerRequestFilter，重写doFilterInternal()方法，具体如下。
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;
import com.lkl.web.maven1.api.help.MyRequestWrapper;
import com.lkl.web.maven1.api.help.MyResponseWrapper;
/**
* 监听所有请求
*
* @author Administrator
*
*/
@Component
public class RequestWrapperFilter extends OncePerRequestFilter {
private MyRequestWrapper requestWrapper;
private MyResponseWrapper reponseWrapper;
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
try {
requestWrapper = new MyRequestWrapper(request);
reponseWrapper = new MyResponseWrapper(response);
filterChain.doFilter(requestWrapper, reponseWrapper);
String requestBody = requestWrapper.getRequestBody();
String reponseBody = reponseWrapper.getResponseBody();
//做你想做的事情
} catch (Exception e) {
//失败时，默认即可
filterChain.doFilter(request, response);
}
}
}
简单总结
1.自定义reques和response无非就是想从流中拿到byte[]，因为在outputStream和inputStream中read()后再次read()会读不到数据。
2.有时候会因为各种请求体或响应体为空导致doFilterInternal失败，因此加个try catch块。
3.注意RequestWrapperFilter中标注@Component。
4.保存日志有可能是高频率的io操作，可通过定时器来定时，选择性保存日志。
以上都是我的个人理解，如有不足，请在评论区指出。不胜感激。
