用java寫出這兩題題目<請各位java大大幫幫忙>

Question

1、檔案資料排序
輸入：建立一個文字檔input.txt，內容為每一行一個數字
輸出：開啟input.txt，讀入檔案中的資料，將資料排序（從小到大），將資料輸出到output.txt，格式仍然是每一行一個數字


２、除錯
以下是一段計算複利之本利和的副程式，參數之balance為帳戶餘額，rate為利率（介於0～1之間的數字，若利率為1%，則rate=0.01），但是這個副程式卻因為漏掉一個關鍵性的機制而無法正確地執行。請寫一個Java應用程式，在程式中呼叫computeInterest() 這個副程式以計算複利的本利和。
注意：除了撰寫主程式之外，您還必須改正computeInterest() 的問題，才能夠正確地執行程式。

public void computeInterest(double balance, double rate) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("帳戶餘額：" + balance);
System.out.println("目前利率：" + rate);
System.out.print("請輸入存款期數：");
String line = br.readLine();
int n = Integer.parseInt(line);
double sum = balance;
for (int i = 0; i < n; i++) {
sum = sum * (1.0 + rate);
}
System.out.println(n + "期之後的本利和為：" + sum);
}

Answer 1

請參考我的做法，
1、檔案資料排序

import java.io.*;
import java.util.*;
public class A {
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new FileReader(new File("input.txt")));
String s = null;
ArrayList al = new ArrayList();
while ((s = br.readLine()) != null) {
al.add(s);
}
br.close();
int[] ary = new int[al.size()];
for (int i = 0; i < ary.length; i++) {
ary[i] = Integer.parseInt((String)al.get(i));
}
Arrays.sort(ary);
PrintWriter pw = new PrintWriter("output.txt");
for (int i = 0; i < ary.length; i++) {
System.out.println(ary[i]);
pw.println(ary[i]);
}
pw.close();
}
}
２、除錯
import java.io.*;

public class B {
public void computeInterest(double balance, double rate) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("帳戶餘額：" + balance);
System.out.println("目前利率：" + rate);
System.out.print("請輸入存款期數：");
String line = null;
try {
line = br.readLine();
} catch (IOException ioe) {
System.err.println("Unidentified number");
System.exit(1);
}
int n = Integer.parseInt(line);
double sum = balance;
for (int i = 0; i < n; i++) {
sum = sum * (1.0 + rate);
}
System.out.println(n + "期之後的本利和為：" + sum);
}

public static void main(String[] args) {
B b = new B();
b.computeInterest(10000.0D, 0.01D);
}
}

Answer 2

第二題
import java.io.*;
public class computeInterest {
double balance;
double rate;
public computeInterest() {}

public static void main(String[] args) throws IOException {
computeInterest compute = new computeInterest();
compute.computeInterest();
}
public void computeInterest() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("請輸入帳戶餘額：");
String line1 = br.readLine();
double balance = Double.parseDouble(line1);
System.out.println("請輸入利率：" );
String line2 = br.readLine();
double rate = Double.parseDouble(line2);
System.out.print("請輸入存款期數：");
String line = br.readLine();
int n = Integer.parseInt(line);
double sum = balance;
for (int i = 0; i < n; i++) {
sum = sum * (1.0 + rate);
}
System.out.println(n + "期之後的本利和為：" + sum);
}

}
---------------------------------------------------------
不然就是,直接給數據
--------------------------------
import java.io.*;
public class computeInterest {
public computeInterest() {}

public static void main(String[] args) throws IOException {
computeInterest compute = new computeInterest();
compute.computeInterest(4000,0.01);//直接給數據
}
public void computeInterest(double balance, double rate) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("帳戶餘額：" + balance);
System.out.println("目前利率：" + rate);
System.out.print("請輸入存款期數：");
String line = br.readLine();
int n = Integer.parseInt(line);
double sum = balance;
for (int i = 0; i < n; i++) {
sum = sum * (1.0 + rate);
}
System.out.println(n + "期之後的本利和為：" + sum);
}

}