本文實例為大家分享了java使用文件流實現查看下載次數的具體代碼，供大家參考，具體內容如下
需求：點擊一個按鈕的次數或者是展示文件，游戲被下載的次數
實現：開辟一個流文件，用來保存被下載的次數，然后讀文件中value，點擊一次value加1，再將此value保存到流文件中。
三種方法：
package cn.tr.test;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.Reader;import java.io.Writer;public class TestDemo { private static int in ; private static File file; public static void main(String[] args) { fun2(); } public static void fun(){ /** 初始化文件中的值為0*/ try { OutputStream out = new FileOutputStream(file); String str = "00"; out.write(str.getBytes()); out.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void fun2() { file= new File("d:/test/d.txt"); if (!file.exists()) { try { file.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { /** 讀取文件中的內容 */ if (file.exists()&&file.length()==0) { fun(); } InputStream is = new FileInputStream(file); byte b[] = new byte[(int) file.length()]; for (int i = 0; i < b.length; i++) { // 值字節在0-255 范圍之內是作為int 來返回的 b[i] = (byte) is.read(); } in =Integer.parseInt(new String(b)); in++; System.out.println("讀出來的"+in); /**再寫入到文件中 */ OutputStream out = new FileOutputStream(file); String str = String.valueOf(in); byte[] bytes = str.getBytes(); for (int i = 0; i < bytes.length; i++) { out.write(bytes[i]); // 一個字節一個字節的寫入 } is.close(); out.close(); System.out.println("寫入的"+in); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public static void fun3(){ file= new File("d:/test/d.txt"); if (!file.exists()) { try { file.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** 先讀出來*/ try { if (file.exists()&&file.length()==0) { fun(); } Reader reader = new FileReader(file); char[] c = new char[(int)file.length()]; int temp = 0; int len =0; while((temp=reader.read()) != -1){ c[len]=(char)temp; len++; } reader.close(); System.out.println("初始值"+new String(c,0,len)); in =Integer.parseInt(new String(c,0,len)); in++; System.out.println("下載一次："+in); /** 再寫進去*/ Writer writer = new FileWriter(file); writer.write(in+""); writer.close(); System.out.println("再寫進去："+in); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void fun4(){ Reader reader; Writer writer; file= new File("d:/test/d.txt"); if (!file.exists()) { try { file.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { if (file.exists()&&file.length()==0) { fun(); } /** 讀出來*/ reader = new FileReader(file); BufferedReader br = new BufferedReader(reader); char [] c = new char[(int)file.length()]; int len = 0; int temp = 0; while((temp=br.read())!= -1){ c[len]=(char)temp; len++; } in =Integer.parseInt(new String(c, 0, len)); in++; System.out.println("讀出來："+ in); /** 寫進去*/ writer =new FileWriter(file); BufferedWriter bw = new BufferedWriter(writer); bw.write(in+""); System.out.println("寫進去："+in); br.close(); bw.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VeVb武林網。
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