Question

我有一个clojure项目，我想用它来使用h2数据库。有没有办法检查数据库是否存在？我试过这样的事情：

(defn mysql-db [] 
  (if (.exists (clojure.java.io/as-file "my-webapp.h2.db"))
    (println "exists")
    (j/with-connection
      {:classname "org.h2.Driver"
       :subprotocol "h2:file"
       :subname "db/my-webapp"}

      (j/create-table :locations
                      [:id "bigint primary key auto_increment"]
                      [:title "varchar (255)"]
                      [:part "clob"])

      (j/insert-records :locations
                        {:title "Steven Gerrard: I'm not the new Beckham"
                         :part "He might not have the Becks appeal -- but Steven Gerrard says he's ready to light up Hollywood in his own way..."}))))

但是.exists函数总是返回false。

Answer 1

我改变了

byte[] content = getContent(packet.getData());
if (content.length > 0) {
    InputStream byteIS = new ByteArrayInputStream(content);
    SessionInputBufferImpl contentBuf = new SessionInputBufferImpl(new HttpTransportMetricsImpl(), content.length);
    contentBuf.bind(byteIS);

    ChunkedInputStream chunkedIS = new ChunkedInputStream(contentBuf);

    GZIPInputStream gzipIS = new GZIPInputStream(chunkedIS);

    while (gzipIS.available() != 0) {
        byte[] buf = new byte[128];
        gzipIS.read(buf);
        contentBuilder.append(new String(buf, "UTF-8"));
    }
    gzipIS.close();
    String contentString = contentBuilder.toString();
}

进入

 (if (.exists (clojure.java.io/as-file "my-webapp.h2.db"))

它有效。我想我没有找到正确的文件夹。

使用clojure检查h2数据库是否已存在？

1 个答案: