Master mau tanya

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String ket = JTextField.getText();
if (ket=="tes"){
JOptionPane.showMessageDialog(null,ket);
}
}
kenapa pas di run ga mau masuk ke if padahal masukin di text field nya tes juga
tpi klo di ganti tipe int mau jalan if nya

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String ket = JTextField.getText();
int tes = Integer.valueOf(ket);
if (tes==1){
JOptionPane.showMessageDialog(null,ket);

}
}

dan klo ga pake if mau run dia
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String ket = JTextField.getText();
JOptionPane.showMessageDialog(null,ket);

}

nah klo kaya gini baru mau masuk if
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String ket = "tes";
if (ket=="tes"){
JOptionPane.showMessageDialog(null,ket);
}
}

mohon pencerahanya master