From 3f7f8007817dae6bc187c361cdb098cf1c8a3966 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=AC=BC=E7=94=BB=E7=AC=A6?= <mail@xnx3.com>
Date: Sat, 26 Oct 2024 10:14:12 +0800
Subject: [PATCH] When using it to intercept responses, if the content of the
 response is compressed, such as gzip, then when fetching the response content
 normally, it is garbled. This solves the problem of garbled characters. If it
 is found to be compressed, the compressed content will be decompressed and
 converted into normal plain text.

---
 .../lightbody/bmp/util/HttpObjectUtil.java    | 70 ++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

diff --git a/browsermob-core/src/main/java/net/lightbody/bmp/util/HttpObjectUtil.java b/browsermob-core/src/main/java/net/lightbody/bmp/util/HttpObjectUtil.java
index 169a878f6..e900a313c 100644
--- a/browsermob-core/src/main/java/net/lightbody/bmp/util/HttpObjectUtil.java
+++ b/browsermob-core/src/main/java/net/lightbody/bmp/util/HttpObjectUtil.java
@@ -5,9 +5,17 @@
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpMessage;
 import net.lightbody.bmp.exception.UnsupportedCharsetException;
+
+import org.apache.commons.io.IOUtils;
+import org.brotli.dec.BrotliInputStream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+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;
 
 /**
@@ -67,6 +75,12 @@ public static void replaceBinaryHttpEntityBody(FullHttpMessage message, byte[] n
 
         // update the Content-Length header, since the size may have changed
         message.headers().set(HttpHeaders.Names.CONTENT_LENGTH, newBinaryContents.length);
+        
+        //find content-encoding , remove it 
+        String encoding = message.headers().get("Content-Encoding");
+        if(encoding != null && encoding.equals("br")) {
+        	message.headers().remove(HttpHeaders.Names.CONTENT_ENCODING);
+        }
     }
 
     /**
@@ -88,6 +102,34 @@ public static String extractHttpEntityBody(HttpContent httpContent, Charset char
         return new String(contentBytes, charset);
     }
 
+    /**
+     * Extracts the entity body from an HTTP content object, according to the specified character set. The character set cannot be null. If
+     * the character set is not specified or is unknown, you still must specify a suitable default charset (see {@link BrowserMobHttpUtil#DEFAULT_HTTP_CHARSET}).
+     *
+     * @param httpContent HTTP content object to extract the entity body from
+     * @param charset character set of the entity body
+     * @param headers headers
+     * @return String representation of the entity body
+     * @throws IllegalArgumentException if the charset is null
+     */
+    public static String extractHttpEntityBody(HttpContent httpContent, Charset charset, HttpHeaders headers) {
+        if (charset == null) {
+            throw new IllegalArgumentException("No charset specified when extracting the contents of an HTTP message");
+        }
+       
+        byte[] contentBytes = BrowserMobHttpUtil.extractReadableBytes(httpContent.content());
+        
+        //经过 br 压缩的要单独处理
+        if(headers != null) {
+        	String en = headers.get(HttpHeaders.Names.CONTENT_ENCODING);
+        	if(en != null && en.equalsIgnoreCase("br")) {
+        		return BrotliToString(new ByteArrayInputStream(contentBytes));
+        	}
+        }
+        
+        return new String(contentBytes, charset);
+    }
+    
     /**
      * Extracts the entity body from a FullHttpMessage, according to the character set in the message's Content-Type header. If the Content-Type
      * header is not present or does not specify a charset, assumes the ISO-8859-1 character set (see {@link BrowserMobHttpUtil#DEFAULT_HTTP_CHARSET}).
@@ -111,7 +153,9 @@ public static String extractHttpEntityBody(FullHttpMessage httpMessage) {
             throw cause;
         }
 
-        return extractHttpEntityBody(httpMessage, charset);
+        //Those that are compressed by br need to be processed separately and converted to plain text.
+        HttpHeaders headers = httpMessage.headers();
+        return extractHttpEntityBody(httpMessage, charset, headers);
     }
 
     /**
@@ -143,4 +187,28 @@ public static Charset getCharsetFromMessage(HttpMessage httpMessage) throws Unsu
     public static byte[] extractBinaryHttpEntityBody(HttpContent httpContent) {
         return BrowserMobHttpUtil.extractReadableBytes(httpContent.content());
     }
+    
+    /**
+     * Convert the compressed text to plain text.
+     * @param is compressed text
+     * @return plain text.
+     */
+    public static String BrotliToString(InputStream is) {
+        try {
+            BrotliInputStream stream = new BrotliInputStream(is);
+            BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
+            StringBuilder result = new StringBuilder();
+            String str = null;
+            while ((str = reader.readLine()) != null) {
+                result.append(str);
+            }
+            return result.toString();
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        } finally {
+            IOUtils.closeQuietly(is);
+        }
+    }
+    
 }