The code does not create a file

[yma16]

Hi All,

I wrote a program to create a file called "rate1.txt". It did not work. How can I make it work? Thanks a lot.

The code is below

try {
File f = new File("rate.txt");
FileInputStream file = new FileInputStream(f);
File f1 = new File("rate1.txt");
f1.createNewFile();
DataOutputStream s10 = new DataOutputStream(
new FileOutputStream(f1));
s10.writeChar(1);
} catch (Exception e) {
System.out.println("Error: " + e.toString());
}

[yma16]

Sorry, it does create a file but the file is empty.

[Fubarable]

Have you tried flushing and then closing the output stream after you're finished with it?

[yma16]

I changed

s10.writeChar(1);

to

s10.writeChar(33);

The code works. But it works in Intellij Idea 12, not in textpad 5. When I run the same code in textpad 5, it only shows a DOS screen with the usage info and not create the file.

[Fubarable]

Please re-read my post above. And yes, you should write printable characters. Also, if you are writing chars to a file, why not use a Writer instead such as a PrintWriter?

[yma16]

The code is part of a java windows application. It should display a window. In Intellij Idea 12, it works. But in textpad 5, the last line in the DOS window is "Press any key to continue...". When I press Enter key, it does not display the window.

[Fubarable]

The code is part of a java windows application. It should display a window.

I'm confused as I see nothing in your code above that should cause a window to be displayed. Is there code that you're not showing us?

[yma16]

I am new to Java. I am trying different ways to test the code. I am going to use FileWriter next time. Thanks.

[Fubarable]

I am new to Java. I am trying different ways to test the code. I am going to use FileWriter next time. Thanks.

That's fine, but you should wrap it in something that does some buffering such as a BufferedWriter that is then wrapped by a PrintWriter.

But back to your main problem -- if your error is in a window not showing and you need our help, you would be wise to show us the code for the window opening as well as describe the problem in greater detail.

[yma16]

The application has two java files and one text file. I list them below. Again, it works in Intellij Idea 12, but not in textpad 5.4.2. I do not know what code caused the problem. Please ingore the original question since I fixed it. Thank you all very much.

Java file 1-LoanProgram2.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class LoanProgram2 extends JFrame implements ActionListener{
double p0=0.0;
Container pane;
JButton compute = new JButton("Compute");
JButton exit = new JButton("Exit");
JLabel l=new JLabel("Selected Term is ");
JLabel a=new JLabel("Enter Loan Amount");
JTextField amt= new JTextField("100000.00");
JLabel pay=new JLabel("");
ButtonGroup group0 = new ButtonGroup( );
JRadioButtonMenuItem year7 = new JRadioButtonMenuItem("7 Years at 5.35%");
JRadioButtonMenuItem year15 = new JRadioButtonMenuItem("15 Years at 5.5%");
JRadioButtonMenuItem year30 = new JRadioButtonMenuItem("30 Years at 5.75%",true);
JTextArea textArea = new JTextArea(10, 50);
public LoanProgram2(){
super("Loan Payment");
setSize(600, 400);
setLocation(200, 50);
JMenuItem quitItem = new JMenuItem("Exit");
compute.addActionListener(this);
exit.addActionListener(this);
quitItem.addActionListener(this);
// create the term menu
JMenu menu1 = new JMenu("Select a Term");
group0.add(year7);
menu1.add(year7);
group0.add(year15);
menu1.add(year15);
group0.add(year30);
menu1.add(year30);
menu1.addSeparator( );
menu1.add(quitItem);
// create a menu bar and use it in this JFrame
JMenuBar menuBar = new JMenuBar();
menuBar.add(menu1);
JScrollPane s = new JScrollPane(textArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane. HORIZONTAL_SCROLLBAR_ALWAYS);
FlowLayout flo = new FlowLayout(FlowLayout.LEFT,10,20);
pane = getContentPane();
pane.setLayout(flo);
pane.add(l);
pane.add(a);
pane.add(amt);
pane.add(pay);
pane.add(compute);
pane.add(exit);
pane.add(s);
setJMenuBar(menuBar);
}

public void actionPerformed(ActionEvent e){
double loans[][] = new double[2][];
loans[0] = new double[360];//principal in each payment
loans[1] = new double[360];//interest in each payment
double l0=0.0, i0=0.0, t0=0.0;
if (e.getActionCommand().equals("Exit")){
System.exit(0);
}
if (e.getActionCommand().equals("Compute")){
if (isNum(amt.getText())){
if (year7.isSelected()){
i0=5.35/1200.0;
t0=7*12;
l.setText(l.getText() + year7.getText() + " Annual Interest.");
}
if (year15.isSelected()){
i0=5.5/1200.0;
t0=15*12;
l.setText(l.getText() + year15.getText() + " Annual Interest.");
}
if (year30.isSelected()){
i0=5.75/1200.0;
t0=30*12;
l.setText(l.getText() + year30.getText() + " Annual Interest.");
}
l0=Double.parseDouble(amt.getText());
p0=pmt(l0,i0,t0);
pay.setText("Monthly Payment is " + p0 + ".");
double principal=0.0, interest=0.0;
textArea.setText("");
textArea.insert("No. Principal Interest\n",0);
for (int k=1; k<=t0; k++){
principal = pamtsCompute(p0,i0,t0, k);
interest = p0-pamtsCompute(p0, i0, t0,k);
interest = Math.round(100*interest)/100.0;
textArea.append(" "+String.valueOf(k) + " " + String.valueOf(principal) + " " + String.valueOf(interest) + "\n");
}
}}
}
double pmt(double l,double i,double n){
p0=l/((1-Math.pow(1/(1+i),n))/i);
p0= Math.round(100*p0)/100.0;
return p0;
}
double pamtsCompute(double p,double i,double n,double k){//p is monthly payment
double pamt;
pamt= p*Math.pow(1/(1+i),(n-k+1));
pamt= Math.round(100*pamt)/100.0;
return pamt;
}
public boolean isNum(String i)
{
try
{
Double.parseDouble(i);
return true;
}
catch(NumberFormatException nfe)
{
pay.setText("Some of the loan inputs is not a number");
return false;
}
}
public static void main(String[] args){
LoanProgram2 f= new LoanProgram2();
f.setVisible(true);
}}

Java file 2-LoanProgram4.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.awt.geom.*;
public class LoanProgram4 extends LoanProgram2{
JButton compute1 = new JButton("Compute from Input");
JButton draw = new JButton("Draw Pies");
JLabel inter=new JLabel("Annual Interest(%):");
JLabel term=new JLabel("Term(Years):");
JComboBox ii = new JComboBox();
JTextField tt= new JTextField(2);
JLabel no=new JLabel("Payment No:");
JLabel drawMsg=new JLabel("");
JTextField payNo= new JTextField(2);
boolean bDraw = false;
double[] iRate;//will hold rates.
double[] iArray;//will hold interest.
double[] pArray;//will hold principal.
DrawPie p;

public LoanProgram4(){
super();
compute1.addActionListener(this);
pane.add(inter);
pane.add(ii);
pane.add(term);
pane.add(tt);
pane.add(compute1);
pane.add(no);
pane.add(payNo);
ii.setEditable(false);
draw.addActionListener(this);
pane.add(draw);
pane.add(drawMsg);
}
public void actionPerformed(ActionEvent e){
double l0=0.0, i0=0.0;
int t0=0;
l.setText(l.getText()+":");
if (e.getActionCommand().equals("Compute from Input")){
if (isNum(amt.getText()) && isInt(tt.getText())){
i0=Double.parseDouble(ii.getSelectedItem().toStrin g())/1200.0;
t0=Integer.parseInt(tt.getText())*12;
l0=Double.parseDouble(amt.getText());
iArray = new double[t0];
pArray = new double[t0];
l.setText("Loan is " + tt.getText() + " years at Annual Interest " + ii.getSelectedItem().toString() + "%.");
p0=pmt(l0,i0,t0);
p0=pmt(l0,i0,t0);
pay.setText("Monthly Payment is " + p0 + ".");
double principal=0.0, interest=0.0;
textArea.setText("");
textArea.insert("No. Principal Interest\n",0);
for (int k=1; k<=t0; k++){
principal = pamtsCompute(p0,i0,t0, k);
interest = p0-pamtsCompute(p0, i0, t0,k);
interest = Math.round(100*interest)/100.0;
pArray[k-1] = principal;
iArray[k-1] = interest;
textArea.append(" "+String.valueOf(k) + " " + String.valueOf(principal) + " " + String.valueOf(interest) + "\n");
}
double totalPrincipal=0.0, totalInterest=0.0, totalPayment=0.0;
for (int k=1; k<=t0; k++){
totalPrincipal=totalPrincipal+ pArray[k-1];
totalInterest=totalInterest+iArray[k-1];
}
totalPayment = totalPrincipal + totalInterest;
totalPrincipal = Math.round(100*totalPrincipal)/100.0;
totalInterest = Math.round(100*totalInterest)/100.0;
totalPayment = Math.round(100*totalPayment)/100.0;
textArea.append(" \n");
textArea.append("Total Principal Total Interest Total Payment\n");
textArea.append(" "+String.valueOf(totalPrincipal) + " " + String.valueOf(totalInterest) + " " + String.valueOf(totalPayment) + "\n");
}}else
if (e.getActionCommand().equals("Compute")){
if (isNum(amt.getText())){
if (year7.isSelected()){
i0=5.35/1200.0;
t0=7*12;
l.setText("Loan is " + year7.getText() + " Annual Interest.");
}
if (year15.isSelected()){
i0=5.5/1200.0;
t0=15*12;
l.setText("Loan is " + year15.getText() + " Annual Interest.");
}
if (year30.isSelected()){
i0=5.75/1200.0;
t0=30*12;
l.setText("Loan is " + year30.getText() + " Annual Interest.");
}
iArray = new double[t0];
pArray = new double[t0];
l0=Double.parseDouble(amt.getText());
p0=pmt(l0,i0,t0);
pay.setText("Monthly Payment is " + p0 + ".");
double principal=0.0, interest=0.0;
textArea.setText("");
textArea.insert("No. Principal Interest\n",0);
for (int k=1; k<=t0; k++){
principal = pamtsCompute(p0,i0,t0, k);
interest = p0-pamtsCompute(p0, i0, t0,k);
interest = Math.round(100*interest)/100.0;
pArray[k-1] = principal;
iArray[k-1] = interest;
textArea.append(" "+String.valueOf(k) + " " + String.valueOf(principal) + " " + String.valueOf(interest) + "\n");
}
double totalPrincipal=0.0, totalInterest=0.0, totalPayment=0.0;
for (int k=1; k<=t0; k++){
totalPrincipal=totalPrincipal+ pArray[k-1];
totalInterest=totalInterest+iArray[k-1];
}
totalPayment = totalPrincipal + totalInterest;
totalPrincipal = Math.round(100*totalPrincipal)/100.0;
totalInterest = Math.round(100*totalInterest)/100.0;
totalPayment = Math.round(100*totalPayment)/100.0;
textArea.append(" \n");
textArea.append("Total Principal Total Interest Total Payment\n");
textArea.append(" "+String.valueOf(totalPrincipal) + " " + String.valueOf(totalInterest) + " " + String.valueOf(totalPayment) + "\n");
}}
else if(e.getActionCommand().equals("Draw Pies")){
if (textArea.getText().equals("")){
drawMsg.setText("Compute a loan before drawing pies.");
}else{
if (isInt(payNo.getText())){
double p1=0,i1=0,p2=0,i2=0,iTotal=0,pTotal=0;
int m=0;
drawMsg.setText("");
m=Integer.parseInt(payNo.getText());
if (m<1 || m>pArray.length){
drawMsg.setText("Payment number should be between 1 and " + pArray.length + ".");
}else{
for(int k=0;k<m;k++){
p1=p1+pArray[k];
i1=i1+iArray[k];
}
for(int k=0;k<pArray.length;k++){
pTotal=pTotal+pArray[k];
iTotal=iTotal+iArray[k];
}
p2=pTotal-p1;
i2=iTotal-i1;
if (bDraw){//Test if p exists.
pane.remove(p); //Tf p exists, remove it. We need to add a new one.
p=null;
}
p = new DrawPie(p1,i1,p2,i2);
p.setPreferredSize(new Dimension(400,400));
pane.add(p);
bDraw=true;//p exists. set bDraw to true.
}
}else{
drawMsg.setText("Enter an integer as payment number.");
}
}}
else{
super.actionPerformed(e);
}
}
public boolean isInt(String i)
{
try
{
Integer.parseInt(i);
return true;
}
catch(NumberFormatException nfe)
{
pay.setText("The loan term is not an integer");
return false;
}
}

void getRate(){
try {
File f = new File("rate.txt");
FileInputStream file = new FileInputStream(f);

File f1 = new File("rate1.txt");
f1.createNewFile();
DataOutputStream s10 = new DataOutputStream(
new FileOutputStream(f1));
s10.writeChar(33);

byte[] b = new byte[100];
file.read(b);
String s = new String(b);
s=s.trim();
int[] i= new int[s.length()];
int k=1;
i[0]=s.indexOf(",");
while (i[k-1]>0) {//put position of commas into i[].
i[k]=s.indexOf(",",i[k-1]+1);
k++;
}
int[] pos =new int[--k];
pos=i;
String s1="";
double[] rate = new double[++k];//will hold rates.
// double[] rate = new double[k];//will hold rates.
rate[0]=Double.parseDouble(s.substring(0,pos[0]));
k--;//k is number of commas.
for (int j=0;j<k;j++) {
if (j==k-1){//last comma postion.
s1=s.substring(pos[j]+1);
//rate[j]=Double.parseDouble(s.substring(pos[j]+1));
rate[j+1]=Double.parseDouble(s.substring(pos[j]+1));
}else{
s1=s.substring(i[j]+1,i[j+1]);
//rate[j]=Double.parseDouble(s.substring(pos[j]+1,pos[j+1]));
rate[j+1]=Double.parseDouble(s.substring(pos[j]+1,pos[j+1]));
}
iRate=rate;
}
file.close();
} catch (Exception e) {
System.out.println("Error: " + e.toString());
}
}
public static void main(String[] args){
LoanProgram4 f= new LoanProgram4();
f.setSize(650,650);
f.setVisible(true);
f.getRate();
for(int n=0;n<f.iRate.length;n++){
f.ii.addItem(new Double(f.iRate[n]));
}
}}
class DrawPie extends JPanel {
double p1,i1,p2,i2;
DrawPie(double pPaid,double iPaid,double pPay,double iPay){
p1=pPaid;
i1=iPaid;
p2=pPay;
i2=iPay;
}
public void paintComponent(Graphics comp) {
super.paintComponent(comp);
Graphics2D comp2D = (Graphics2D)comp;
Rectangle2D.Double r1 = new Rectangle2D.Double(10,10,40,40);
comp2D.setColor(Color.cyan);
Rectangle2D.Double r2 = new Rectangle2D.Double(10,60,40,40);
Rectangle2D.Double r3 = new Rectangle2D.Double(10,110,40,40);
Rectangle2D.Double r4 = new Rectangle2D.Double(10,160,40,40);
double total = p1+p2+i1+i2;
double ext1=p1/total*360.0,ext2=i1/total*360.0;
double ext3=p2/total*360.0,ext4=i2/total*360.0;
double w=200, h=150;
double x=200, y=50;
comp2D.setColor(Color.blue);
comp2D.fill(r1);
comp2D.drawString("Principal have been paid", 60,30);
Arc2D.Double a1 = new Arc2D.Double(x,y,w,h,0,ext1,Arc2D.Double.PIE);
comp2D.fill(a1);
comp2D.setColor(new Color(50,155,50));
comp2D.fill(r2);
comp2D.drawString("Inerest have been paid", 60,80);
Arc2D.Double a2 = new Arc2D.Double(x,y,w,h,ext1,ext2,Arc2D.Double.PIE);
comp2D.fill(a2);
comp2D.setColor(Color.magenta);
comp2D.fill(r3);
comp2D.drawString("Loan Balance", 60,130);
Arc2D.Double a3 = new Arc2D.Double(x,y,w,h,ext1+ext2,ext3,Arc2D.Double.P IE);
comp2D.fill(a3);
comp2D.setColor(Color.red);
comp2D.fill(r4);
comp2D.drawString("Future Inerest", 60,180);
Arc2D.Double a4 = new Arc2D.Double(x,y,w,h,ext1+ext2+ext3,ext4,Arc2D.Dou ble.PIE);
comp2D.fill(a4);
}
}

The text file is rate.txt. The content is
2.75,2.875,2.99,3.0,3.125,3.25,3.375,3.5,3.75,4.0, 4.25,4.5,4.75,5.0,5.25,5.5,5.75,6.0,6.25,6.5

[Fubarable]

Please edit your post above and place code tags around your code so that it retains its formatting. To do this you'd do something like this:

[code]

//... your code block goes here

[/code]

Note that the top and bottom tags are different, and you must use square brackets and the slash as I demonstrate here. For more, see my link below.

[yma16]

I updated the textpad to 6. It works now. Thanks a lot.