从数据库中搜索图像但不在java jlable中显示 [英] Searching image from a database but not display in the java jlable

问题描述

我几乎尝试过所有事情......请帮助任何人。输出显示为：run：

BUILD SUCCESSFUL（总时间：8秒）

但是图像没有显示在jLable中



我尝试过：



CrimiID = this.txtCriID.getText（）;



字符串查询=SELECT * FROM criminal WHERE CriminalID ='+ CrimiID +';



DBConnection.DBConnection （）;



尝试{



语句s = DBConnection.con.createStatement（）;

ResultSet rs = s.executeQuery（Query）;

while（rs.next（））{

java.sql.Blob FileNameBlob = rs。 getBlob（ 照片）;

byte [] content = FileNameBlob.getBytes（1L，（int）FileNameBlob.length（））;

ImageIcon ik = new ImageIcon（content）;

final BufferedImage image = ImageIO.read（new ByteArrayInputStream（content））;

Image img = ik.getImage（）;

Image newimg = img.getScaledInstance （this.jLabelPhoto.getWidth（），this.jLabelPhoto.getHeight（），java.awt.Image.SCALE_SMOOTH）;

ik = new ImageIcon（newimg）;

this.jLabelPhoto.setIcon（ik）;

} catch（SQLException ex）{



JOptionPane.showMessageDialog（null，ex.getMessage（ ））;



}

}

I have tried nearly everything... Please help anyone. The output is showing as: run:
BUILD SUCCESSFUL (total time: 8 seconds)
But the image is not displaying in the jLable

What I have tried:

CrimiID = this.txtCriID.getText();

String Query = "SELECT * FROM criminal WHERE CriminalID = '"+CrimiID+"'";

DBConnection.DBConnection();

try {

Statement s = DBConnection.con.createStatement();
ResultSet rs = s.executeQuery(Query);
while(rs.next()){
java.sql.Blob FileNameBlob = rs.getBlob("Photo");
byte[] content = FileNameBlob.getBytes(1L, (int) FileNameBlob.length());
ImageIcon ik = new ImageIcon(content);
final BufferedImage image = ImageIO.read(new ByteArrayInputStream(content));
Image img = ik.getImage();
Image newimg = img.getScaledInstance(this.jLabelPhoto.getWidth(), this.jLabelPhoto.getHeight(), java.awt.Image.SCALE_SMOOTH);
ik = new ImageIcon(newimg);
this.jLabelPhoto.setIcon(ik);
} catch (SQLException ex) {

JOptionPane.showMessageDialog(null, ex.getMessage());

}
}

解决方案

在使用数据库时请使用正确准备好的语句和参数。

SQL注入在90年代后期被识别出来，不幸的是它仍然在＃ 12网站漏洞。



所以我看到的第一个错误是在你的SQL语句中

你可以学习如何正确地准备语句和使用Oracle网站上的参数：使用准备语句（The Java™Tutorials> JDBC（TM）数据库访问> JDBC基础知识） [ ^ ]

字符串查询=SELECT * FROM criminal WHERE CriminalID ='+ CrimiID +';

应替换为

字符串查询=SELECT * FROM criminal WHERE CriminalID =？;



通常情况下，我会给出完整的代码，但是我不会在我的开发机器上使用它。我使用了类似于Stack Overflow解决方案的代码：

java - 将数据库中的blob图像显示到jlabel中 - Stack Overflow [ ^ ]

Please use properly prepared statements and parameters when working with a database.
SQL Injection was identified back in the late 90s and unfortunately it is still in the #12 vulnerability in websites.

So the first error I see is in your SQL statement
You can learn how to properly prepare statements and use parameters on Oracle's website: Using Prepared Statements (The Java™ Tutorials > JDBC(TM) Database Access > JDBC Basics)[^]
String Query = "SELECT * FROM criminal WHERE CriminalID = '"+CrimiID+"'";
should be replaced with
String Query = "SELECT * FROM criminal WHERE CriminalID = ?";

Normally I would give the full code, but I am not on my development machine with it handy. I have used code similar to this Stack Overflow solution:
java - Display blob image from database into jlabel - Stack Overflow[^]

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