fix: fix download failed with 405 response code when backend can't su…

…pport HEAD method

close #942

demo/src/main/assets/filedownloader.properties

@@ -78,3 +78,13 @@ file.non-pre-allocation=false
 # Default false.
 #
 broadcast.completed=false
+
+# Whether you want the first trial connection with HEAD method to request to backend or not.
+#
+# if this value is true, the first trial connection will with HEAD method instead of GET method and
+# then you will reduce 1 byte cost on the response body, but if the backend can't support HEAD
+# method you will receive 405 response code and failed to download.
+#
+# Default false.
+#
+download.trial-connection-head-method=false

library/src/main/java/com/liulishuo/filedownloader/download/ConnectionProfile.java

@@ -17,6 +17,7 @@
 package com.liulishuo.filedownloader.download;
 
 import com.liulishuo.filedownloader.connection.FileDownloadConnection;
+import com.liulishuo.filedownloader.util.FileDownloadProperties;
 import com.liulishuo.filedownloader.util.FileDownloadUtils;
 
 import java.net.ProtocolException;
@@ -73,7 +74,7 @@ private ConnectionProfile(long startOffset, long currentOffset, long endOffset,
     public void processProfile(FileDownloadConnection connection) throws ProtocolException {
         if (isForceNoRange) return;
 
-        if (isTrialConnect) {
+        if (isTrialConnect && FileDownloadProperties.getImpl().trialConnectionHeadMethod) {
             connection.setRequestMethod("HEAD");
         }
 

library/src/main/java/com/liulishuo/filedownloader/util/FileDownloadProperties.java

@@ -112,6 +112,16 @@
  * 'filedownloader.intent.action.completed' action name on 'AndroidManifest.xml'.
  * <p>
  * You can use {@link FileDownloadBroadcastHandler} class to parse the received intent.
+ * <p/>
+ * Key {code download.trial-connection-head-method}
+ * Value: {@code true} or {@code false}
+ * Default: {@code false}.
+ * Such as download.trial-connection-head-method=false
+ * Description:
+ * Whether you want the first trial connection with HEAD method to request to backend or not, if
+ * this value is true, the first trial connection will with HEAD method instead of GET method and
+ * then you will reduce 1 byte cost on the response body, but if the backend can't support HEAD
+ * method you will receive 405 response code and failed to download.
  */
 public class FileDownloadProperties {
 
@@ -123,6 +133,7 @@ public class FileDownloadProperties {
             "download.max-network-thread-count";
     private static final String KEY_FILE_NON_PRE_ALLOCATION = "file.non-pre-allocation";
     private static final String KEY_BROADCAST_COMPLETED = "broadcast.completed";
+    private static final String KEY_TRIAL_CONNECTION_HEAD_METHOD = "download.trial-connection-head-method";
 
     public final int downloadMinProgressStep;
     public final long downloadMinProgressTime;
@@ -131,6 +142,7 @@ public class FileDownloadProperties {
     public final int downloadMaxNetworkThreadCount;
     public final boolean fileNonPreAllocation;
     public final boolean broadcastCompleted;
+    public final boolean trialConnectionHeadMethod;
 
     public static class HolderClass {
         private static final FileDownloadProperties INSTANCE = new FileDownloadProperties();
@@ -160,6 +172,7 @@ private FileDownloadProperties() {
         String downloadMaxNetworkThreadCount = null;
         String fileNonPreAllocation = null;
         String broadcastCompleted = null;
+        String downloadTrialConnectionHeadMethod = null;
 
         Properties p = new Properties();
         InputStream inputStream = null;
@@ -177,6 +190,7 @@ private FileDownloadProperties() {
                         .getProperty(KEY_DOWNLOAD_MAX_NETWORK_THREAD_COUNT);
                 fileNonPreAllocation = p.getProperty(KEY_FILE_NON_PRE_ALLOCATION);
                 broadcastCompleted = p.getProperty(KEY_BROADCAST_COMPLETED);
+                downloadTrialConnectionHeadMethod = p.getProperty(KEY_TRIAL_CONNECTION_HEAD_METHOD);
             }
         } catch (IOException e) {
             if (e instanceof FileNotFoundException) {
@@ -262,6 +276,7 @@ private FileDownloadProperties() {
             this.fileNonPreAllocation = false;
         }
 
+        // broadcast.completed
         if (broadcastCompleted != null) {
             if (!broadcastCompleted.equals(TRUE_STRING)
                     && !broadcastCompleted.equals(FALSE_STRING)) {
@@ -275,15 +290,31 @@ private FileDownloadProperties() {
             this.broadcastCompleted = false;
         }
 
+        // download.trial-connection-head-method
+        if (downloadTrialConnectionHeadMethod != null) {
+            if (!downloadTrialConnectionHeadMethod.equals(TRUE_STRING)
+                    && !downloadTrialConnectionHeadMethod.equals(FALSE_STRING)) {
+                throw new IllegalStateException(
+                        FileDownloadUtils.formatString("the value of '%s' must be '%s' or '%s'",
+                                KEY_TRIAL_CONNECTION_HEAD_METHOD, TRUE_STRING, FALSE_STRING));
+            }
+            this.trialConnectionHeadMethod = downloadTrialConnectionHeadMethod.equals(TRUE_STRING);
+        } else {
+            this.trialConnectionHeadMethod = false;
+        }
+
         if (FileDownloadLog.NEED_LOG) {
             FileDownloadLog.i(FileDownloadProperties.class, "init properties %d\n load properties:"
-                            + " %s=%B; %s=%B; %s=%d; %s=%d; %s=%d",
+                            + " %s=%B; %s=%B; %s=%d; %s=%d; %s=%d; %s=%B; %s=%B; %s=%B",
                     System.currentTimeMillis() - start,
                     KEY_HTTP_LENIENT, this.httpLenient,
                     KEY_PROCESS_NON_SEPARATE, this.processNonSeparate,
                     KEY_DOWNLOAD_MIN_PROGRESS_STEP, this.downloadMinProgressStep,
                     KEY_DOWNLOAD_MIN_PROGRESS_TIME, this.downloadMinProgressTime,
-                    KEY_DOWNLOAD_MAX_NETWORK_THREAD_COUNT, this.downloadMaxNetworkThreadCount);
+                    KEY_DOWNLOAD_MAX_NETWORK_THREAD_COUNT, this.downloadMaxNetworkThreadCount,
+                    KEY_FILE_NON_PRE_ALLOCATION, this.fileNonPreAllocation,
+                    KEY_BROADCAST_COMPLETED, this.broadcastCompleted,
+                    KEY_TRIAL_CONNECTION_HEAD_METHOD, this.trialConnectionHeadMethod);
         }
     }