UrlUtil.getFileName先尝试截取

app/src/main/java/io/legado/app/utils/UrlUtil.kt

@@ -1,5 +1,7 @@
 package io.legado.app.utils
 
+import io.legado.app.model.analyzeRule.AnalyzeUrl
+import io.legado.app.constant.AppLog
 import java.net.HttpURLConnection
 import java.net.URL
 import java.net.URLDecoder
@@ -29,19 +31,33 @@ object UrlUtil {
             .replace("|", "%7C")
     }
 
+
+    /* 阅读定义的url,{urlOption} */
+    fun getFileName(analyzeUrl: AnalyzeUrl): String? {
+        return getFileName(analyzeUrl.url, analyzeUrl.headerMap)
+    }
+
     /**
-     * 根据网络url获取文件名
+     * 根据网络url获取文件信息 文件名
      */
-    fun getFileName(fileUrl: String): String? {
+    fun getFileName(fileUrl: String, headerMap: <String, String>? = null): String? {
+        // 如果获取到后缀可直接截取链接
+        if (getSuffix(fileUrl, "") != "") return fileUrl.substringAfterLast("/")
         return kotlin.runCatching {
             var fileName: String
             val url = URL(fileUrl)
             val conn: HttpURLConnection = url.openConnection() as HttpURLConnection
-            // head方式
+            // HEAD方式获取返回头信息
             conn.requestMethod = "HEAD"
+            // 下载链接可能还需要书源header才能成功访问
+            headerMap?.forEach { key, value ->
+                conn.setRequestProperty(key, value)
+            }
             conn.connect()
 
-            // 方法一
+            // val contentLength = conn.getContentLengthLong()
+            // Content-Disposition
+            // 解析文件名 filename= filename*=
             val raw: String? = conn.getHeaderField("Content-Disposition")
             if (raw != null && raw.indexOf("=") > 0) {
                 fileName = raw.split("=".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()[1]
@@ -50,16 +66,33 @@ object UrlUtil {
                         fileName.toByteArray(StandardCharsets.ISO_8859_1),
                         StandardCharsets.UTF_8 //?
                     )
-            } else {
-                // 方法二 截取
+            } else if (conn.getHeaderField("Location") != null) {
+                // Location跳转到实际的下载链接
                 var newUrl: String = conn.url.path ?: return null
                 newUrl = URLDecoder.decode(newUrl, "UTF-8")
-                fileName = newUrl.substringAfterLast("/")
+                if (getSuffix(newUrl, "") != "") {
+                    fileName = newUrl.substringAfterLast("/")
+                }
+            } else {
+                // 其余情况 返回响应头
+                val headers = conn.getHeaderFields()
+                val headersString = buildString {
+                    headers.forEach( key, value ->
+                        value.forEach {
+                            append(key)
+                            append(": ")
+                            append(it)
+                            append("\n")
+                        }
+                    )
+                }
+                AppLog.putDebug("Cannot obtain URL file name:\n$headersString")
             }
             fileName
         }.getOrNull()
     }
 
+    /* 获取合法的文件后缀 */
     fun getSuffix(url: String, default: String): String {
         val suffix = url.substringAfterLast(".").substringBeforeLast(",")
         //检查截取的后缀字符是否合法 [a-zA-Z0-9]