从数据库读出的JPG文件的字符流，转换成图片显示在页面上的相关代码
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
ServletOutputStream out = res.getOutputStream();
Statement dispStmt = null, setStmt = null;
try {
dispStmt = Con.createStatement();
setStmt = Con.createStatement();
setStmt.executeUpdate("set textsize 2048000");
} catch (Exception e) {
out.println("Create Statement error:" + e.toString() + "<br>");
}
String ls_sql = null;
ls_sql = req.getParameter("ImageSQL");
if (ls_sql == null)
ls_sql = "";
ls_sql = ls_sql.trim();
if (!ls_sql.equals("")) {
ResultSet rs = null;
try {
rs = dispStmt.executeQuery(ls_sql);
} catch (Exception e) {
System.out.println(
"Unable to Exec Statment" + e.toString() + "<br>");
}
try {
while (rs.next()) {
try {
res.setContentType("image/jpeg");
InputStream is = rs.getBinaryStream(1);
int size = is.available();
byte[] bzp = new byte[size];
is.read(bzp);
out.write(bzp);
} catch (Exception e) {
System.out.println("Wirte image error: " + e.toString());
}
}
rs.close();
} catch (Exception e) {
System.out.println("Unable to Close Statment" + e.toString());
}
}
try {
dispStmt.close();
} catch (Exception e) {
System.out.println("Close Statement Error: " + e.toString());
}
out.close();
}