Question

我想将画布保存到MySQL数据库（BLOB单元格）中。我在javaScript中有函数

    function saveCanvas(){
    var canvas = document.getElementById("canvas");

    var dataURL = canvas.toDataURL("image/png");
    dataURL = dataURL.replace(/^data:image\/(png|jpeg);base64,/, "");    
    var req = $.ajax({
        url: "Canvases",
        type: "Post",
        data: "operation=0&sessionId=" + readCookie('sessionId') + "&title=" + document.getElementById('imageNameTextbox').value + "&pic=" + dataURL,
        success: function(){
        }
    });
}

然后我用Java来存储我的图像

BASE64Decoder decoder = new BASE64Decoder();

 byte[] pic = decoder.decodeBuffer(request.getParameter("pic"));
 CanvasController.AddCanvas(sessionId, new CanvasModel(0, 0, request.getParameter("title"), pic));

并插入数据库：

  String insertStatement = "INSERT INTO Canvas(userId, title, pic) VALUES (?, ?, ?);";
  prepStmt = connection.prepareStatement(insertStatement);
  prepStmt.setInt(1, id);
  prepStmt.setString(2, canvas.getTitle());
  prepStmt.setBytes(3, canvas.getPic());
  prepStmt.executeUpdate();

运行之后我总是在db中得到空图像。当我将image / png更改为image / jpeg并绘制为例如：

http://imageshack.us/photo/my-images/714/pobranec.jpg

我明白了：

http://imageshack.us/photo/my-images/15/pobrane2q.jpg

你能说出我做错了吗？

Answer 1

您的数据字符串编码不正确，导致在服务器上收到数据并从邮件正文中提取数据时出现损坏。将您的data更改为此：

    data: {
       operation: 0,
       sessionId:  readCookie('sessionId'),
       title : document.getElementById('imageNameTextbox').value,
       pic: dataURL
    }

让jquery为你处理编码。

在MySQL数据库中保存画布

1 个答案: