本文实例为大家分享了java使用文件流实现查看下载次数的具体代码,供大家参考,具体内容如下
需求:点击一个按钮的次数或者是展示文件,游戏被下载的次数
实现:开辟一个流文件,用来保存被下载的次数,然后读文件中value,点击一次value加1,再将此value保存到流文件中。
三种方法:
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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(){ /** 初始化文件中的值为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 { /** 读取文件中的内容 */ 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++) { // 值字节在0-255 范围之内是作为int 来返回的 b[i] = ( byte ) is.read(); } in =integer.parseint( new string(b)); in++; system.out.println( "读出来的" +in); /**再写入到文件中 */ 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]); // 一个字节一个字节的写入 } is.close(); out.close(); system.out.println( "写入的" +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(); } } /** 先读出来*/ 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( "下载一次:" +in); /** 再写进去*/ writer writer = new filewriter(file); writer.write(in+ "" ); writer.close(); system.out.println( "再写进去:" +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(); } /** 读出来*/ 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( "读出来:" + in); /** 写进去*/ writer = new filewriter(file); bufferedwriter bw = new bufferedwriter(writer); bw.write(in+ "" ); system.out.println( "写进去:" +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内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/xusheng_mr/article/details/78801506