java nio reading lines from a file

How do i implement a function in java nio say nextLineNio() which reads next line from FileChannel incrementally as the file could be huge, my initial idea was to read into a ByteBuffer of size greater then maximum length of a line which could exist and read() from the FileChannel if required, but the problem which i see is how do i un-read the last sequence of bytes which do not end in a newline

Java nio从文件读取行

我如何在Java中实现一个函数nio say nextLineNio()从FileChannel增量读取下一行,因为文件可能很大,我最初的想法是读入一个ByteBuffer,它的大小大于一行可能存在并读取的最大长度()从FileChannel如果需要,但我看到的问题是我如何解读不以换行符结束的最后一个字节序列。 另外我如何确保nextLineNio()函数不会失败,因为nio api是异步的。 任何帮助或已有的实现? 谢谢 正如@EJP指出的那样,使用BufferedReader.re

Java NIO Servlet to File

Is there a way (without buffering the whole Inputstream) to take the HttpServletRequest from a Java Servlet and write it out to a file using all NIO? Is it even worth trying? Will it be any faster reading from a normal java.io stream and writing to a java.nio Channel or do they both really need to be pure NIO to see a benefit? Thanks. EDIT: So I just did a quick and dirty benchmark, readin

Java NIO Servlet到文件

有没有一种方法(不缓冲整个InputStream)从Java Servlet中获取HttpServletRequest并使用所有NIO将其写入文件? 它甚至值得尝试吗? 它是否能够更快地读取正常的java.io流并写入java.nio Channel?或者它们是否都需要纯粹的NIO才能看到好处? 谢谢。 编辑: 所以我只做了一个快速而肮脏的基准测试,从一个磁盘读取一个文件并写入另一个磁盘(所以我实际测试的是代码而不是磁盘)。 Averages: InputStream -> OutputStr

Java sockets: can I write a TCP server with one thread?

From what I read about Java NIO and non-blocking [Server]SocketChannels, it should be possible to write a TCP server that sustains several connections using only one thread - I'd make a Selector that waits for all relevant channels in the server's loop. Is that right, or am I missing some important detail? What problems can I encounter? (Background: The TCP communication would be for

Java套接字:我可以用一个线程写一个TCP服务器吗?

从我读到的有关Java NIO和非阻塞[Server] SocketChannels的内容中,应该可以编写一个只使用一个线程来维持多个连接的TCP服务器 - 我将创建一个Selector来等待服务器循环中的所有相关通道。 这是对的,还是我错过了一些重要的细节? 我可以遇到什么问题? (背景:TCP通信适用于小型多人游戏,因此最多可同时连接10-20个连接消息,每隔几秒会发送一次消息。) 你是对的。 您可能遇到的问题是处理持续时间过长。 在这种情

Java wildcard in multi

Why Bar.go is OK with argument f2 but not with argument f1 ? public class HelloWorld { public static void main(String[] args) { Foo<Foo<?>> f1 = new Foo<Foo<?>>(); Foo<Foo<String>> f2 = new Foo<Foo<String>>(); Bar.go(f1); // not OK Bar.go(f2); // OK } public static void p(Object o) { Syst

多通用Java通配符

为什么Bar.go OK使用参数f2但不使用参数f1 ? public class HelloWorld { public static void main(String[] args) { Foo<Foo<?>> f1 = new Foo<Foo<?>>(); Foo<Foo<String>> f2 = new Foo<Foo<String>>(); Bar.go(f1); // not OK Bar.go(f2); // OK } public static void p(Object o) { System.out.println(o);

How to allow specific characters with OWASP HTML Sanitizer?

I am using the OWASP Html Sanitizer to prevent XSS attacks on my web app. For many fields that should be plain text the Sanitizer is doing more than I expect. For example: HtmlPolicyBuilder htmlPolicyBuilder = new HtmlPolicyBuilder(); stripAllTagsPolicy = htmlPolicyBuilder.toFactory(); stripAllTagsPolicy.sanitize('a+b'); // return a&#43;b stripAllTagsPolicy.sanitize('foo@example.com'); //

如何通过OWASP HTML Sanitizer允许特定字符?

我正在使用OWASP Html Sanitizer来防止我的Web应用程序受到XSS攻击。 对于许多应该是纯文本的领域,Sanitizer的工作量超出了我的预期。 例如: HtmlPolicyBuilder htmlPolicyBuilder = new HtmlPolicyBuilder(); stripAllTagsPolicy = htmlPolicyBuilder.toFactory(); stripAllTagsPolicy.sanitize('a+b'); // return a&#43;b stripAllTagsPolicy.sanitize('foo@example.com'); // return foo&#64;example.com 当我

blocking SSL server using Thrift

Thrift provides several different non-blocking server models, like TNonblockingServer , THsHaServer , and TThreadedSelectorServer . But, I'd like to enable SSL on the server. It seems SSL only works on blocking servers in Thrift. Anyone has any clues of a non-blocking SSL server in Thrift? Java example would be highly appreciated. One alternative to worrying about SSL in your Java App

使用Thrift阻止SSL服务器

Thrift提供了几种不同的非阻塞服务器模型,如TNonblockingServer , THsHaServer和TThreadedSelectorServer 。 但是,我想在服务器上启用SSL 。 看起来SSL只适用于Thrift中的阻塞服务器。 任何人都有Thrift中的非阻塞SSL服务器的线索? Java的例子将不胜感激。 在Java应用程序中担心SSL的一种替代方法是将nginx(http://wiki.nginx.org/SSL-Offloader)作为反向代理。 这有利于您的应用程序不需要关心SSL,但需要在堆栈

invalidateOptionsMenu() not working when "restarting" activity

I have an activity, let's call it FirstActivity.java , which has an actionBar with a navigation drawer instantiated via fragment. In this fragment, NavigationDrawerFragment.java , I've put the methods onCreateOptionsMenu(Menu menu, MenuInflater inflater), onOptionsItemSelected(MenuItem item) and onPrepareOptionsMenu(Menu menu) as anyone normally would in order to instantiate the actionBa

invalidateOptionsMenu()在“重新启动”活动时不起作用

我有一个活动,我们称它为FirstActivity.java ,它具有一个带有通过片段实例化的导航抽屉的actionBar 。 在这个片段中, NavigationDrawerFragment.java ,我已经将任何通常为了实例化actionBar的onCreateOptionsMenu(菜单菜单,MenuInflater inflater),onOptionsItemSelected(MenuItem项目)和onPrepareOptionsMenu(菜单菜单)放在方法中。 在actionBar的右侧,我有一个带有“messages”图标的按钮,这个图标通向用户的收

drawing textures in opengl es 2.0

I have been having a problem with drawing texture in opengl es 2 on android for about 3 days and finally decided i should help after all my researching lead to dead ends. The problem is the texture is drawn as a black rectangle and not the actually image. public class Sprite { private static final Shader spriteShader = ShaderManager.getInstance().getShader(1); private static final shor

在opengl es 2.0中绘制纹理

我一直在android上的opengl es 2绘制纹理的问题约3天,最后决定我应该帮助所有我的研究导致死路一条。 问题是纹理被绘制成一个黑色的矩形而不是实际的图像。 public class Sprite { private static final Shader spriteShader = ShaderManager.getInstance().getShader(1); private static final short[] drawOrder = { 0, 1, 2, 0, 2, 3 }; private static ShortBuffer drawListBuffer; static {

Sorting student test scores in an array

I am given an integer, N, which is the number of test scores that will be inputted. For each line, N, there will be a student name followed their test score. I need to compute the sum of their test scores & print the the second-smallest student's name. So, what I would do is create an array of classes for the students. The class would have two instance variables for the name and scor

在数组中排列学生测试分数

我得到一个整数N,它是将要输入的测试分数。 对于每一行,N,都会有一个学生姓名,并跟着他们的考试成绩。 我需要计算他们考试成绩的总和并打印出第二个最小的学生的名字。 所以,我会做的是为学生创建一个类的数组。 该类将有两个名称和分数的实例变量。 然后当所有的输入完成后,你需要做的就是获得它们。 下面是我为这个确切的事情提出的代码。 import java.util.*; public class testScores { public static vo

Grid walking algorithm code correction

Grid Walking (Score 50 points): You are situated in an N dimensional grid at position (x_1,x2,...,x_N) . The dimensions of the grid are (D_1,D_2,...D_N) . In one step, you can walk one step ahead or behind in any one of the N dimensions. (So there are always 2N possible different moves). In how many ways can you take M steps such that you do not leave the grid at any point? You leave the gri

网格步行算法代码校正

网格散步 (得分50分):您位于位置(x_1,x2,...,x_N)的N维网格中。 网格的尺寸是(D_1,D_2,...D_N) 。 在一个步骤中,您可以在N维度中的任何一个维度上向前或向后走一步。 (所以总有2N可能的不同动作)。 在多少种方式中,你可以采取M步骤,以便在任何时候都不会离开电网? 如果您有任何x_i ( x_i <= 0 or x_i > D_i ,则离开网格。 输入:第一行包含测试用例T的数量。 T测试用例如下。 对于每个测试用例,第一