[Fix #11] 修复在图片缓存失效的情况下, 'getImageToBotCode'依然会尝试从缓存获取图片File对象导致NPE;

[Change] BotCommandProcess 调整字符串拼接形式, 统一错误提示语的格式;

src/main/java/net/lamgc/cgj/bot/cache/ImageCacheHandler.java

@@ -1,6 +1,7 @@
 package net.lamgc.cgj.bot.cache;
 
 import net.lamgc.cgj.Main;
+import net.lamgc.cgj.bot.cache.exception.HttpRequestException;
 import net.lamgc.cgj.pixiv.PixivURL;
 import net.lamgc.cgj.util.URLs;
 import net.lamgc.utils.event.EventHandler;
@@ -60,8 +61,9 @@ public class ImageCacheHandler implements EventHandler {
                 throw e;
             }
             if(response.getStatusLine().getStatusCode() != 200) {
-                log.warn("Http请求异常：{}", response.getStatusLine());
-                throw new IOException("Http Response Error: " + response.getStatusLine());
+                HttpRequestException requestException = new HttpRequestException(response);
+                log.warn("Http请求异常：{}", requestException.getStatusLine());
+                throw requestException;
             }
 
             log.debug("正在下载...(Content-Length: {}KB)", response.getEntity().getContentLength() / 1024);

src/main/java/net/lamgc/cgj/bot/cache/ImageCacheStore.java

@@ -1,9 +1,14 @@
 package net.lamgc.cgj.bot.cache;
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.google.gson.Gson;
+import com.google.gson.JsonObject;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import net.lamgc.cgj.bot.cache.exception.HttpRequestException;
+
 import java.util.Hashtable;
 import java.util.Map;
 import java.util.concurrent.*;
@@ -34,29 +39,30 @@ public final class ImageCacheStore {
      * 传递图片缓存任务, 并等待缓存完成.
      * @param cacheObject 缓存任务组
      */
-    public static void executeCacheRequest(ImageCacheObject cacheObject) throws InterruptedException {
+    public static Throwable executeCacheRequest(ImageCacheObject cacheObject) throws InterruptedException {
         Task task = getTaskState(cacheObject);
         if(task.taskState.get() == TaskState.COMPLETE) {
-            return;
+            return null;
         }
 
         boolean locked = false;
         try {
             if(task.taskState.get() == TaskState.COMPLETE) {
-                return;
+                return null;
             }
             task.lock.lock();
             locked = true;
             // 双重检查
             if(task.taskState.get() == TaskState.COMPLETE) {
-                return;
+                return null;
             }
 
             // 置任务状态
             task.taskState.set(TaskState.RUNNING);
 
+            Throwable throwable = null;
             try {
-                Throwable throwable = imageCacheExecutor.submit(() -> {
+                throwable = imageCacheExecutor.submit(() -> {
                     try {
                         handler.getImageToCache(cacheObject);
                     } catch (Throwable e) {
@@ -73,6 +79,7 @@ public final class ImageCacheStore {
             } catch (ExecutionException e) {
                 log.error("执行图片缓存任务时发生异常", e);
             }
+            return throwable;
         } finally {
             if(locked) {
                 task.lock.unlock();
@@ -88,6 +95,23 @@ public final class ImageCacheStore {
         return cacheMap.get(cacheObject);
     }
 
+    /**
+     * 获取错误信息
+     */
+    public static String getErrorMessageFromThrowable(Throwable throwable, boolean onlyRequestException) {
+        if(throwable == null) {
+            return "";
+        } else if(!(throwable instanceof HttpRequestException)) {
+            if(onlyRequestException) {
+                return "";
+            }
+            return throwable.getMessage();
+        }
+        JsonObject result = new Gson()
+            .fromJson(((HttpRequestException) throwable).getContent(), JsonObject.class);
+        return result.get("msg").getAsString();
+    }
+
     /**
      * 任务状态
      */

src/main/java/net/lamgc/cgj/bot/cache/exception/HttpRequestException.java

@@ -0,0 +1,44 @@
+package net.lamgc.cgj.bot.cache.exception;
+
+import java.io.IOException;
+import java.util.Objects;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.StatusLine;
+import org.apache.http.util.EntityUtils;
+
+public class HttpRequestException extends IOException {
+
+    private static final long serialVersionUID = -2229221075943552798L;
+
+    private final StatusLine statusLine;
+
+    private final String content;
+
+    public HttpRequestException(HttpResponse response) throws IOException {
+        this(response.getStatusLine(), EntityUtils.toString(response.getEntity()));
+    }
+
+    public HttpRequestException(StatusLine statusLine, String content) {
+        super("Http Response Error: " + Objects.requireNonNull(statusLine, "statusLine is null") +
+               ", Response Content: " + (content == null ? "null" : '\'' + content + '\''));
+        this.statusLine = statusLine;
+        this.content = content;
+    }
+
+    /**
+     * 获取Http状态行
+     */
+    public StatusLine getStatusLine() {
+        return statusLine;
+    }
+
+    /**
+     * 获取Response内容
+     * @return 如果没有返回, 则返回null
+     */
+    public String getContent() {
+        return content;
+    }
+
+}