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hossain aboutalebi
how to write a simple interpreter in java that can execute simple commandes like adding two integers and sysout a result and calling java classes and executing the methodes in that class .
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August 14, 2012 at 4:16 PM
Well although there was nobody found to answer this tricky question I myself answered it :
The first class (main class):
package bb;
import java.io.File;
import java.io.FileNotFoundException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
public class main {
static Object o;
static int j=0;
static Object []ss=new Object[10];
static Object []dd=new Object[10];
static HashMap<String , Object> map= new HashMap<String, Object>();
public static void main(String[] args) throws Exception {
Scanner s=new Scanner(System.in);
System.out.println("Please Enter File Name !");
File x=new File(s.nextLine());
Scanner sc=new Scanner(x);
do{
String h=sc.nextLine();
if(h.contains("=")){
String[]hh=h.split(" ");
if(hh[2].equals("=")){
//Double� d� =� new� Double(14.7);
Class c=Class.forName(hh[0]);
if(h.contains("new")==true){
String co=hh[4].substring(hh[4].indexOf("(")+1, hh[4].length()-2);
String[] input=co.split(",");
Class []cInput=Getinput(input);
Object o=GetObject(c,cInput,ss);
map.put(hh[1], o);
}else{
//Long� l� =� d.LongValue();
if(map.containsKey(hh[3].substring(0, hh[3].indexOf(".")))==false){
MethodesFeilds mf=new MethodesFeilds (hh[3].substring(0,hh[3].length()-1),map);
Object o=mf.main();
map.put(hh[1], o);
}else{
Object o=map.get(hh[3].substring(0, hh[3].indexOf(".")));
Object o2=ObjectMethod(o,o.getClass(),hh[3].substring(hh[3].indexOf(".")+1,hh[3].length()-1));
map.put(hh[1], o2);
}
}
}else if(hh[1].equals("=")){
// d=new boolean(false);
Class c=map.get(hh[0]).getClass();
map.remove(hh[0]);
if(h.contains("new")==true){
String co=hh[3].substring(hh[3].indexOf("(")+1, hh[3].length()-2);
String[] input=co.split(",");
Class []cInput=Getinput(input);
Object o=GetObject(c,cInput,ss);
map.put(hh[0], o);
}else{
//� l� =� d.LongValue();
if(map.containsKey(hh[2].substring(0, hh[2].indexOf(".")))==false){
MethodesFeilds mf=new MethodesFeilds (hh[2].substring(0,hh[2].length()-1),map);
Object o=mf.main();
map.put(hh[0], o);
}else{
Object o=map.get(hh[2].substring(0, hh[2].indexOf(".")));
Object o2=ObjectMethod(o,o.getClass(),hh[2].substring(hh[2].indexOf(".")+1,hh[2].length()-1));
map.put(hh[0], o2);
}
}
}
}else{
MethodesFeilds x1=new MethodesFeilds(h.substring(0,h.length()-1),map);
x1.main();
}
}while(sc.hasNext()==true);
}
public static Class[] Getinput( String[] input) {
if(input.length==1&&input[0].equals("")){
Class[]o2=new Class[0];
return o2;}
else{Class[]o=new Class[input.length];
for (int i = 0; i < input.length; i++) {
if( map.containsKey(input[i]) ){
ss[i]=map.get(input[i]);
if(ss[i].getClass().equals(Long.class))
o[i]=long.class;
else if(ss[i].getClass().equals(Double.class)){
o[i]=double.class;
}
else if (ss[i].getClass().equals(String.class)) {
o[i]=String.class;
}else if((ss[i].toString().charAt(0)==('f')||ss[i].toString().charAt(0)==('t'))) {
o[i]=boolean.class;
}else{
o[i]=int.class;
}
}
else if(input[i].contains(".")){
o[i]=double.class;
ss[i]=Double.parseDouble(input[i] );
}
else if (input[i].charAt(0)==('"')||input[i].contains("'")) {
o[i]=String.class;
ss[i]=input[i].substring(1,input[i].length()-1);
}else if((input[i].charAt(0)==('f')||input[i].charAt(0)==('t'))) {
o[i]=boolean.class;
ss[i]=Boolean.parseBoolean (input[i] );
}else{
o[i]=int.class;
ss[i]=Integer.parseInt(input[i] );
}
}
return o;}
}
public static Object GetObject(Class c, Class[] cInput,Object[]x) throws Exception {
if(cInput.length==0){
Object o=c.newInstance();
return o;
}else if(cInput.length==1){
Constructor cons =c.getConstructor(cInput[0]);
Object o=cons.newInstance(x[0]);
return o;
}else if(cInput.length==2){
Constructor cons =c.getConstructor(cInput[0],cInput[1]);
Object o=cons.newInstance(x[0],x[1]);
return o;
}else if(cInput.length==3){
Constructor cons =c.getConstructor(cInput[0],cInput[1],cInput[2]);
Object o=cons.newInstance(x[0],x[1],x[2]);
return o;
}
return null;
}
public static Object ObjectMethod(Object o2, Class c, String input) throws Exception {
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
while(input.equals("")==false){
int i=x.length-1;
while(i>=0){
if(input.contains("(")&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o2, null);
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o2, dd[0]);
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o2, dd[0],dd[1]);
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o2, dd[0],dd[1],dd[2]);
}
}else{
Field f=c.getDeclaredField(x[j]);
o =f.get(o2);
}
i--;
j++;
c=o.getClass();
}
input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));}
}
return o;
}
}
The second class(Methodes Fields):
package bb;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
public class MethodesFeilds {
static Object []ss=new Object[10];
String input;
HashMap<String,Object>map=new HashMap<String,Object>();
Object o=null;
int j=3;
public MethodesFeilds(String x, HashMap<String,Object> map2){
map=map2;
input=x;
}
public Object main() throws Exception {
if(input.contains("java.lang.")){
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
Class c=Class.forName("java.lang."+x[2]);
int i=x.length-4;
while(input.equals("")==false){
while(i>=0){
if((b.equals("")==false)&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o, null);
if(o==null)break;
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o, ss[0]);
if(o==null)break;
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o, ss[0],ss[1]);
if(o==null)break;
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o, ss[0],ss[1],ss[2]);
if(o==null)break;
}
}else{
Field f=c.getDeclaredField(x[j]);
o=f.get(o);
}
i--;
j++;
c=o.getClass();
}input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));}
}
}else
{
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
Class c=Class.forName(x[0]);
j=1;
int i=x.length-2;
while(input.equals("")==false){
while(i>=0){
if(input.contains("(")&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o, null);
if(o==null)break;
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o, ss[0]);
if(o==null)break;
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o, ss[0],ss[1]);
if(o==null)break;
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o, ss[0],ss[1],ss[2]);
if(o==null)break;
}
}else{
Field f=c.getDeclaredField(x[j]);
Object o=f.get(null);
}
i--;
j++;
c=o.getClass();
}input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
}
}
}
return o;
}
public Class[] Getinput( String[] input) {
if(input.length==1&&input[0].equals("")){
Class[]o2=new Class[0];
return o2;}
else{
Class[]o=new Class[input.length];
for (int i = 0; i < input.length; i++) {
if( map.containsKey(input[i]) ){
ss[i]=map.get(input[i]);
if(ss[i].getClass().equals(Long.class))
o[i]=long.class;
else if(ss[i].getClass().equals(Double.class)){
o[i]=double.class;
}
else if (ss[i].getClass().equals(String.class)) {
o[i]=String.class;
}else if((ss[i].toString().charAt(0)==('f')||ss[i].toString().charAt(0)==('t'))) {
o[i]=boolean.class;
}else{
o[i]=int.class;
}
}
else if(input[i].contains(".")){
o[i]=double.class;
ss[i]=Double.parseDouble(input[i] );
}
else if (input[i].charAt(0)==('"')||input[i].contains("'")) {
o[i]=String.class;
ss[i]=input[i].substring(1,input[i].length()-1);
}else if((input[i].charAt(0)==('f')||input[i].charAt(0)==('t'))) {
o[i]=boolean.class;
ss[i]=Boolean.parseBoolean (input[i] );
}else{
o[i]=int.class;
ss[i]=Integer.parseInt(input[i] );
}
}
return o;
}}
}
for more information contact me with my mail:
August 14, 2012 at 4:16 PM
Well although there was nobody found to answer this tricky question I myself answered it :
The first class (main class):
package bb;
import java.io.File;
import java.io.FileNotFoundException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
public class main {
static Object o;
static int j=0;
static Object []ss=new Object[10];
static Object []dd=new Object[10];
static HashMap<String , Object> map= new HashMap<String, Object>();
public static void main(String[] args) throws Exception {
Scanner s=new Scanner(System.in);
System.out.println("Please Enter File Name !");
File x=new File(s.nextLine());
Scanner sc=new Scanner(x);
do{
String h=sc.nextLine();
if(h.contains("=")){
String[]hh=h.split(" ");
if(hh[2].equals("=")){
//Double� d� =� new� Double(14.7);
Class c=Class.forName(hh[0]);
if(h.contains("new")==true){
String co=hh[4].substring(hh[4].indexOf("(")+1, hh[4].length()-2);
String[] input=co.split(",");
Class []cInput=Getinput(input);
Object o=GetObject(c,cInput,ss);
map.put(hh[1], o);
}else{
//Long� l� =� d.LongValue();
if(map.containsKey(hh[3].substring(0, hh[3].indexOf(".")))==false){
MethodesFeilds mf=new MethodesFeilds (hh[3].substring(0,hh[3].length()-1),map);
Object o=mf.main();
map.put(hh[1], o);
}else{
Object o=map.get(hh[3].substring(0, hh[3].indexOf(".")));
Object o2=ObjectMethod(o,o.getClass(),hh[3].substring(hh[3].indexOf(".")+1,hh[3].length()-1));
map.put(hh[1], o2);
}
}
}else if(hh[1].equals("=")){
// d=new boolean(false);
Class c=map.get(hh[0]).getClass();
map.remove(hh[0]);
if(h.contains("new")==true){
String co=hh[3].substring(hh[3].indexOf("(")+1, hh[3].length()-2);
String[] input=co.split(",");
Class []cInput=Getinput(input);
Object o=GetObject(c,cInput,ss);
map.put(hh[0], o);
}else{
//� l� =� d.LongValue();
if(map.containsKey(hh[2].substring(0, hh[2].indexOf(".")))==false){
MethodesFeilds mf=new MethodesFeilds (hh[2].substring(0,hh[2].length()-1),map);
Object o=mf.main();
map.put(hh[0], o);
}else{
Object o=map.get(hh[2].substring(0, hh[2].indexOf(".")));
Object o2=ObjectMethod(o,o.getClass(),hh[2].substring(hh[2].indexOf(".")+1,hh[2].length()-1));
map.put(hh[0], o2);
}
}
}
}else{
MethodesFeilds x1=new MethodesFeilds(h.substring(0,h.length()-1),map);
x1.main();
}
}while(sc.hasNext()==true);
}
public static Class[] Getinput( String[] input) {
if(input.length==1&&input[0].equals("")){
Class[]o2=new Class[0];
return o2;}
else{Class[]o=new Class[input.length];
for (int i = 0; i < input.length; i++) {
if( map.containsKey(input[i]) ){
ss[i]=map.get(input[i]);
if(ss[i].getClass().equals(Long.class))
o[i]=long.class;
else if(ss[i].getClass().equals(Double.class)){
o[i]=double.class;
}
else if (ss[i].getClass().equals(String.class)) {
o[i]=String.class;
}else if((ss[i].toString().charAt(0)==('f')||ss[i].toString().charAt(0)==('t'))) {
o[i]=boolean.class;
}else{
o[i]=int.class;
}
}
else if(input[i].contains(".")){
o[i]=double.class;
ss[i]=Double.parseDouble(input[i] );
}
else if (input[i].charAt(0)==('"')||input[i].contains("'")) {
o[i]=String.class;
ss[i]=input[i].substring(1,input[i].length()-1);
}else if((input[i].charAt(0)==('f')||input[i].charAt(0)==('t'))) {
o[i]=boolean.class;
ss[i]=Boolean.parseBoolean (input[i] );
}else{
o[i]=int.class;
ss[i]=Integer.parseInt(input[i] );
}
}
return o;}
}
public static Object GetObject(Class c, Class[] cInput,Object[]x) throws Exception {
if(cInput.length==0){
Object o=c.newInstance();
return o;
}else if(cInput.length==1){
Constructor cons =c.getConstructor(cInput[0]);
Object o=cons.newInstance(x[0]);
return o;
}else if(cInput.length==2){
Constructor cons =c.getConstructor(cInput[0],cInput[1]);
Object o=cons.newInstance(x[0],x[1]);
return o;
}else if(cInput.length==3){
Constructor cons =c.getConstructor(cInput[0],cInput[1],cInput[2]);
Object o=cons.newInstance(x[0],x[1],x[2]);
return o;
}
return null;
}
public static Object ObjectMethod(Object o2, Class c, String input) throws Exception {
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
while(input.equals("")==false){
int i=x.length-1;
while(i>=0){
if(input.contains("(")&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o2, null);
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o2, dd[0]);
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o2, dd[0],dd[1]);
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o2, dd[0],dd[1],dd[2]);
}
}else{
Field f=c.getDeclaredField(x[j]);
o =f.get(o2);
}
i--;
j++;
c=o.getClass();
}
input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));}
}
return o;
}
}
The second class(Methodes Fields):
package bb;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
public class MethodesFeilds {
static Object []ss=new Object[10];
String input;
HashMap<String,Object>map=new HashMap<String,Object>();
Object o=null;
int j=3;
public MethodesFeilds(String x, HashMap<String,Object> map2){
map=map2;
input=x;
}
public Object main() throws Exception {
if(input.contains("java.lang.")){
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
Class c=Class.forName("java.lang."+x[2]);
int i=x.length-4;
while(input.equals("")==false){
while(i>=0){
if((b.equals("")==false)&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o, null);
if(o==null)break;
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o, ss[0]);
if(o==null)break;
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o, ss[0],ss[1]);
if(o==null)break;
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o, ss[0],ss[1],ss[2]);
if(o==null)break;
}
}else{
Field f=c.getDeclaredField(x[j]);
o=f.get(o);
}
i--;
j++;
c=o.getClass();
}input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));}
}
}else
{
String a=input.substring(0, input.indexOf("("));
String b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
String[]x=a.split("\\.");
Class c=Class.forName(x[0]);
j=1;
int i=x.length-2;
while(input.equals("")==false){
while(i>=0){
if(input.contains("(")&&i==0){
String[] Minput=b.split(",");
Class []cInput=Getinput(Minput);
if(cInput.length==0){
Method m= c.getDeclaredMethod(x[x.length-1], null);
o=m.invoke(o, null);
if(o==null)break;
}else if(cInput.length==1){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0]);
o=m.invoke(o, ss[0]);
if(o==null)break;
}else if(cInput.length==2){
Method m= c.getDeclaredMethod(x[x.length-1], cInput[0],cInput[1]);
o=m.invoke(o, ss[0],ss[1]);
if(o==null)break;
}else if(cInput.length==3){
Method m= c.getClass().getDeclaredMethod(x[x.length-1], cInput[0],cInput[1],cInput[2]);
o=m.invoke(o, ss[0],ss[1],ss[2]);
if(o==null)break;
}
}else{
Field f=c.getDeclaredField(x[j]);
Object o=f.get(null);
}
i--;
j++;
c=o.getClass();
}input=input.substring( input.indexOf(")")+1, input.length());
if(input.equals("")==false) {
a=input.substring(0, input.indexOf("("));
x=a.split("\\.");
b=input.substring(input.indexOf("(")+1, input.indexOf(")"));
}
}
}
return o;
}
public Class[] Getinput( String[] input) {
if(input.length==1&&input[0].equals("")){
Class[]o2=new Class[0];
return o2;}
else{
Class[]o=new Class[input.length];
for (int i = 0; i < input.length; i++) {
if( map.containsKey(input[i]) ){
ss[i]=map.get(input[i]);
if(ss[i].getClass().equals(Long.class))
o[i]=long.class;
else if(ss[i].getClass().equals(Double.class)){
o[i]=double.class;
}
else if (ss[i].getClass().equals(String.class)) {
o[i]=String.class;
}else if((ss[i].toString().charAt(0)==('f')||ss[i].toString().charAt(0)==('t'))) {
o[i]=boolean.class;
}else{
o[i]=int.class;
}
}
else if(input[i].contains(".")){
o[i]=double.class;
ss[i]=Double.parseDouble(input[i] );
}
else if (input[i].charAt(0)==('"')||input[i].contains("'")) {
o[i]=String.class;
ss[i]=input[i].substring(1,input[i].length()-1);
}else if((input[i].charAt(0)==('f')||input[i].charAt(0)==('t'))) {
o[i]=boolean.class;
ss[i]=Boolean.parseBoolean (input[i] );
}else{
o[i]=int.class;
ss[i]=Integer.parseInt(input[i] );
}
}
return o;
}}
}
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