While (rs), next ()) {
//access 'student id' this column data
Cj [I] [j]=rs. Get string (" student id "); J++;
//get 'name' this column data
Cj [I] [j]=rs. Get string (" name "); J++;
//get 'math' this column data
Cj [I] [j]=rs. Get string (" math "); J++;
//get 'language result this column data
Cj [I] [j]=rs. Get string (" language result "); J++;
//output
i++;
}
The database connection success!
Java. Lang. NullPointerException
The at CJLR. Mysql. Cha (mysql. Java: 77)
The at CJLR. The jiemian $1. The actionPerformed (jiemian. Java: 36)
The at javax.mail. Swing. AbstractButton. FireActionPerformed (Unknown Source)
The at javax.mail. Swing. AbstractButton $Handler. The actionPerformed (Unknown Source)
The at javax.mail. Swing. DefaultButtonModel. FireActionPerformed (Unknown Source)
The at javax.mail. Swing. DefaultButtonModel. SetPressed (Unknown Source)
CodePudding user response:
Add i++ behind j=0;