如何在jsp中显示blob图像

Question

//when i display images in jsp page this error is showing...

//The image “http://localhost:8080/TestProject/blobrtv1.jsp?n=vipi” cannot be displayed 

//because it contains errors.

//my code is below....

   <%@page import="java.sql.*" %>

<%@page import="java.io.*" %>

<%!Connection con;

    Statement stmt;

    ResultSet rs7;%>


<%  String name = request.getParameter("n");

            out.println("Name" + name);

            try

            {
                byte b;

                byte imgData[] = null;

                Blob image;


                Class.forName("com.mysql.jdbc.Driver");

                con = DriverManager.getConnection("jdbc:mysql://localhost:3306/customer", 

"root", "root");

                stmt = con.createStatement();

                rs7 = stmt.executeQuery("SELECT (cusPic) from cusinfo where cusName='" + 

name + "'");
                if (rs7.next())

                {
                    out.println("cheking if loop\n");

                    image = rs7.getBlob(1);

                    out.println("\nImage is "+image);

                    imgData = image.getBytes(1, (int) image.length());

                    out.println("\nImgData is"+imgData);

                } else

                {
                    out.println("Display Blob Example");

                    out.println("image not found for given id>");

                    return;
                }
                // display the image

                response.setContentType("image/jpg");

                OutputStream o = response.getOutputStream();

                o.write(imgData);
%>


<%
                o.flush();

                o.close();

            } catch (Exception e)

            {
                out.println("Unable To Display image");

                out.println("Image Display Error=" + e.getMessage());

                return;

            } finally
            {
                try
                {
                    rs7.close();

                    stmt.close();

                    con.close();

                } catch (SQLException e)

                {

                    e.printStackTrace();

                }
            }
%>

Answer 1

尝试修改以下代码：

<%  
Connection con = FactoryConnection_SQL_SERVER.getConnection("Organograma");  
Statement stSuper = con.createStatement();  
Statement stSetor = con.createStatement();  

Blob image = null;  
byte[] imgData = null;  

ResultSet rsSuper = stSuper.executeQuery("Select * From funChart where setor = 'mySetor'");  

if (rsSuper.next()) {  
image = rsSuper.getBlob(12);  
imgData = image.getBytes(1, (int) image.length());  
response.setContentType("image/gif");  
OutputStream o = response.getOutputStream();  
//o.write(imgData); //
//o.flush();  
//o.close();  

--[...]  

<table style="margin: 0px; margin-top: 15px;">  
<tr>  
<td id="foto">  
    <img title="<%=rsSuper.getString("Nome").trim()%>" src="<%= o.wite(imageData); o.flush(); o.close(); %>" />  
</td>  
</td>  

<td id="dados">  
<h3><%=rsSuper.getString("Nome")%></h3>  
<p><%=rsSuper.getString("Cargo")%></p>  
<p>Matrícula:<br/><%=rsSuper.getString("Chave")%></p>  
<p>Telefone:<br/><%=rsSuper.getString("Fone")%></p>  
<p>E-Mail:<br/><%=rsSuper.getString("Email")%></p>  
</td>  
</table>  

Answer 2

我不是java开发人员，但如果我正确理解代码，您将尝试通过写入包含图像的整个字节数组来通过响应对象输出图像...

我认为正确的方法是：

o.write( 'data:image/jpeg;base64,' +
    '/9j/4AAQSkZJRgABAQEASABIAAD/4gv4SUNDX1BST0ZJTEUAAQEAAAvoAAAAAAIAAABtbnRyUkdCIFhZ' +
    'WiAH2QADABsAFQAkAB9hY3NwAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAAAA9tYAAQAAAADTLQAA' +
    'AAAp+D3er/JVrnhC+uTKgzkNAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABBkZXNjAAABRAAA' +
    'AHliWFlaAAABwAAAABRiVFJDAAAB1AAACAxkbWRkAAAJ4AAAAIhnWFlaAAAKaAAAABRnVFJDAAAB1AAA' +
    'CAxsdW1pAAAKfAAAABRtZWFzAAAKkAAAACRia3B0AAAKtAAAABRyWFlaAAAKyAAAABRyVFJDAAAB1AAA' +
    'CAx0ZWNoAAAK3AAAAAx2dWVkAAAK6AAAAId3dHB0AAALcAAAABRjcHJ0AAALhAAAADdjaGFkAAALvAAA' +
    'ACxkZXNjAAAAAAAAAB9zUkdCIElFQzYxOTY2LTItMSBibGFjayBzY2FsZWQAAAAAAAAAAAAAAAAAAAAA' +
    'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' .... and so on and so forth (remaining bytes encoded in Base64).);