我想从数据库中检索图像，该图像存储为 blob，该图像是员工的个人资料图像，因此图像中会包含一些其他详细信息，例如姓名、职务等，因此我在员工详细信息中传递 servlet 路径和值。 jsp ，它会转到那个 servlet，一切都是正确的，比如查询、参数，但最后在 employeedetail.jsp 页面上图像没有出现，它只是显示一个十字符号，请任何人帮助我，这里是代码..
登录.Java
public class Login extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
HttpSession session = request.getSession();
// InputStream sImage;
String sid = request.getParameter("eid");
session.setAttribute("sid", sid);
String password = request.getParameter("password");
try {
Connection con = ConnectionManager.getConnection();
String query = "select eid, name, password, sex, dob, bloodgroup, fathername, qualification, mailid, contactnum, skills, temporaryadd, permanentadd, access_type
from empinfo where eid = '" + sid+ "' AND password = '" + password + "' ";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
if (rs.next()) {
String n1 = rs.getString("eid");
String n2 = rs.getString("name");
String n3 = rs.getString("password");
String n4 = rs.getString("sex");
String n5 = rs.getString("dob");
String n6 = rs.getString("bloodgroup");
String n7 = rs.getString("fathername");
String n8 = rs.getString("qualification");
String n9 = rs.getString("mailid");
String n10 = rs.getString("contactnum");
String n11 = rs.getString("skills");
String n12 = rs.getString("temporaryadd");
String n13 = rs.getString("permanentadd");
String n14 = rs.getString("access_type");
// sImage = rs.getBinaryStream("image");
session.setAttribute("eid", n1);
session.setAttribute("name", n2);
session.setAttribute("password", n3);
session.setAttribute("sex", n4);
session.setAttribute("dob", n5);
session.setAttribute("bloodgroup", n6);
session.setAttribute("fathername", n7);
session.setAttribute("qualification", n8);
session.setAttribute("mailid", n9);
session.setAttribute("contactnum", n10);
session.setAttribute("skills", n11);
session.setAttribute("temporaryadd", n12);
session.setAttribute("permanentadd", n13);
session.setAttribute("access_type", n14);
//session.setAttribute("image",sImage);
response.sendRedirect("EmployeeDetail.jsp");
} else {
String message = "Your are not a registered employee.";
request.setAttribute("message", message);
request.getRequestDispatcher("index.jsp").forward(request, response);
}
} catch (Throwable theException) {
System.out.println(theException);
}
}
}
员工详细信息.jsp
<html>
<head>
<style>
</style>
</head>
<body>
<table align=center cellspacing=1 cellpadding=3>
<tr><Td> Employee name</td><Td><%=name%></td></tr>
<tr>
<td><img src="${pageContext.servletContext.contextPath }/retImage?param1= <%=eid%>">image</td>
// here i am passing the value and it is passing to servlet also
</tr>
<tr><Td>Password</td><Td><%=password%></td></tr>
<tr><Td>Sex</td><Td><%=sex%></td></tr>
<tr><Td>dob</td><Td><%=dob%></td></tr>
<tr><Td>Blodgroup</td><Td><%=bloodgroup%></td></tr>
<tr><Td>fathername</td><Td><%=fathername%></td></tr>
<tr><Td>Qualification</td><Td><%=qualification%></td></tr>
<tr><Td>mail id</td><Td><%=mailid%></td></tr>
<tr><Td>contact num</td><Td><%=contactnum%></td></tr>
<tr><Td>skills</td><Td><%=skills%></td></tr>
<tr><Td>local address</td><Td><%=temporaryadd%></td></tr>
<tr><Td>permanent Address</td><Td><%=permanentadd%></td></tr>
<tr><Td>Emp Category</td><Td><%=access_type%></td></tr>
</table><BR>
</div>
</body>
</html>
retImage.java
public class retImage extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException
{
HttpSession session = request.getSession(true);
String sid=(String)session.getAttribute("eid");
session.setAttribute("sid",sid);
System.out.println("sid is " +sid);
String iid = request.getParameter("param1");
InputStream sImage;
try {
Connection con = ConnectionManager.getConnection();
String Query= "SELECT image FROM empinfo WHERE eid ='"+iid+"'";
System.out.println("Query is" +Query);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(Query);
System.out.println("..........1");
if(rs.next())
{
System.out.println("........2");
byte[] bytearray = new byte[1048576];
int size=0;
sImage = rs.getBinaryStream(1);
response.reset();
while((size=sImage.read(bytearray))!= -1 ) {
response.getOutputStream().write(bytearray,0,size);
System.out.println(".......3");
}
}
}
catch(Exception ex){
System.out.println("error :"+ex);
}
}
}
最佳答案
在retImage.java中添加finally block ，如下所示:-
public class retImage extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException
{
......
// replace InputStream sImage with sImageBytes
byte[] sImageBytes;
try {
.....
if(rs.next())
{
...
sImageBytes = rs.getBytes()
response.setContentType("image/jpeg");
response.setContentLength(sImageBytes.length);
// Give the name of the image in the name variable in the below line
response.setHeader("Content-Disposition", "inline; filename=\"" + name+ "\"");
BufferedInputStream input = new BufferedInputStream(new ByteArrayInputStream(sImageBytes));
BufferedOutputStream output = new BufferedOutputStream(response.getOutputStream());
byte[] buffer = new byte[8192];
int length;
while ((length = input.read(buffer)) > 0) {
output.write(buffer, 0, length);
System.out.println(".......3");
}
}
}
catch(Exception ex){
System.out.println("error :"+ex);
}
}
}
关于java - 使用java中的其他正常数据值将图像从servlet检索到jsp，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25135454/