让我们逐步查看会发生什么：
应该是这样。它几乎自己编写代码。让我们从HTML（在JSP中）开始：
<img src="${pageContext.request.contextPath}/images/foo.png">
<img src="${pageContext.request.contextPath}/images/bar.png">
<img src="${pageContext.request.contextPath}/images/baz.png">
必要时，可以动态地也设置src有EL而使用迭代JSTL：
<c:forEach items="${imagenames}" var="imagename">
<img src="${pageContext.request.contextPath}/images/${imagename}">
</c:forEach>
然后定义/创建一个servlet，该servlet侦听URL模式为的GET请求/images/*，以下示例将普通的JDBC用于作业：
@WebServlet("/images/*")
public class ImageServlet extends HttpServlet {
// content=blob, name=varchar(255) UNIQUE.
private static final String sql_FIND = "SELECT content FROM Image WHERE name = ?";
@Resource(name="jdbc/yourDB") // For Tomcat, define as <Resource> in context.xml and declare as <resource-ref> in web.xml.
private DataSource dataSource;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String imageName = request.getPathInfo().substring(1); // Returns "foo.png".
try (Connection connection = dataSource.getConnection(); PreparedStatement statement = connection.prepareStatement(sql_FIND)) {
statement.setString(1, imageName);
try (ResultSet resultSet = statement.executeQuery()) {
if (resultSet.next()) {
byte[] content = resultSet.getBytes("content");
response.setContentType(getServletContext().getMimeType(imageName));
response.setContentLength(content.length);
response.getOutputStream().write(content);
} else {
response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
}
}
} catch (sqlException e) {
throw new ServletException("Something Failed at sql/DB level.", e);
}
}
}
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