private void jButtonStiahniActionPerformed(java.awt.event.ActionEvent evt) {
//start the Rengine (JRI)
String src,symbol1,symbol2 = null,title;
REXP exp2;
Rengine re = new Rengine(null, false, null);
re.eval("library('quantmod')");
if(!boolOanda){
src="yahoo";
symbol1=jComboBoxSymbols.getSelectedItem().toString();
re.eval("kurz=getSymbols('"+symbol1+"',src='"+src+"')");
exp2 = re.eval(symbol1+"$"+symbol1+".Close");
}
else {
src="oanda";
symbol1=jComboBoxSymbols.getSelectedItem().toString();
symbol2=jComboBoxSymbols2.getSelectedItem().toString();
re.eval("kurz=getSymbols('"+symbol1+"/"+symbol2+"',src='"+src+"')");
exp2 = re.eval(symbol1+symbol2);
}
double[] kurz = exp2.asDoubleArray();
re.end();
}
我在double[] kurz = exp2.asDoubleArray();
了java.lang.NullPointerException
當我試圖把這個JButton的秒時間。第一次一切順利,但第二次我有例外。它似乎像變量exp2爲空,但我不明白爲什麼。謝謝你提前顯示java.lang.NullPointerException第二次嘗試
謝謝大家,我終於解決了它。我宣佈 Rengine re = new Rengine(null,false,null); 作爲類變量(或全局)及其工作。 – troger19 2010-10-29 08:31:25