Java Programming

how to execute multiple commands through java programming .I tried with the code
Process pro=Runtime.getRuntime().exec("cmd /c cd C:\\Symbian\\Carbide\\MyXmlParserWeb\\group\\s60_3rd");
pro.waitFor();
BufferedReader reader=new BufferedReader(new InputStreamReader(pro.getInputStream()));
String line=reader.readLine();
while(line!=null)
{
System.out.println(line);
line=reader.readLine();
}


for(int i=0;i<2;i++){
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Process pro4=Runtime.getRuntime().exec("bldmake clean");
pro.waitFor();
BufferedReader reader4=new BufferedReader(new InputStreamReader(pro4.getInputStream()));
String line4=reader4.readLine();
while(line4!=null)
{
System.out.println(line4);
line4=reader4.readLine();
}


for(int i=0;i<2;i++){
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Process pro1=Runtime.getRuntime().exec("bldmake bldfiles");
pro1.waitFor();
BufferedReader reader1=new BufferedReader(new InputStreamReader(pro1.getInputStream()));
String line1=reader1.readLine();
while(line1!=null)
{
System.out.println(line1);
line1=reader.readLine();
}
for(int i=0;i<2;i++){
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}