SEARCH KEYWORD -- NIO


  NIO vs IO in Java

Java 1.4 provides a new API for handling IO -- NIO. This is a non-blocking and buffer oriented IO API. Below are main differences between the NIO and IO in Java. IO NIO Stream oriented Buffer oriented Blocking IO Non-blocking IO N/A Using selector Stream oriented vs Buffer oriented The main difference is that IO is stream oriented where the data is read byte by byte and the data will not be buffered normally.This means there is no pointer to move forward and backward in the stream. I...

   JAVA,IO,NIO     2016-01-10 01:40:02

  Check file readability in Java

File operation is quite platform dependent. Although Java is a cross platform programming language, the file operation in Java is also platform dependent. The obvious evidence is the file permission check. In Java, we can call canRead(), canWrite() and canExecutable() to check whether the program can read, write or execute the file specified. However, on Windows, when we call canRead() on a File object, we may get unexpected result. Actually, on Windows, when we call canRead() on a File object, ...

   Java,Files,Readable,Check     2013-12-05 06:10:15

  Using MemoryMappedBuffer to handle large file in Java

When handling large files, it will largely affect the process speed while using traditional FileInputStream, FileOutputStream or RandomAccessFile since they trigger lots of read and write operations. In Java NIO, a new way of handling large file is introduced which is to use MmeoryMappedBuffer to create memory mapped file. Memory-mapped I/O uses the filesystem to establish a virtual memory mapping from user space directly to the applicable filesystem pages. With a memory-mapped file, you can pre...

   JAVA,IO,NIO     2015-11-13 01:58:08

  ByteBuffer in Java

ByteBuffer is introduced in java.nio since Java 1.4. It provides a way of representing raw structured data such as from a file or from network. It enables fast access of underlying data compared to traditional ways like byte[] Prior to Java 1.4, if you want to represent a structured raw data, you need to create a byte[] and then having a set of checks to delimit the byte array to get the expected tokens. There are three ways to create a ByteBuffer: Wrapping an exiting array by calling ByteBuffe...

   JAVA,BYTEBUFFER,ALLOCATION     2015-07-08 03:17:44

  The Risks of Prioritizing Features Over Security in China's EV Industry

In recent years, China's electric vehicle (EV) industry has seen a surge in innovation and growth. Companies like BYD, NIO, XPeng, and Xiaomi have become household names, not just in China but globally. These companies have been at the forefront of integrating cutting-edge technology into their vehicles, often promoting new features such as autonomous driving, advanced infotainment systems, and seamless connectivity. However, this rapid pace of innovation has raised concerns about whether these...

   SECURITY,CHINA,EV CAR     2024-11-20 01:14:18

  Set file permission in Java

Prior to Java 6,  there is no good solution at the Java level to provide file permission management. You need to implement your own native methods or call the Runtime.exec() to invoke the system routine such as chmod in LInux. Since Java 6, Java introduces a set of methods which can be used to set the file permission at Java level. These methods include: File.setReadable(boolean); File.setWritable(boolean); FIle.setExecutable(boolean); File.setReadable(boolean, boolean); File.setWritable(bo...

   JAVA, FILE PERMISSION, POSIX,learnjava     2015-08-29 03:37:37

  Generate signed certificate from CSR in Java

In our previous tutorial, we have explained how to generate CSR which can be sent to CA for generating a signed certificate. In this tutorial, we will explain how to generate the signed certificate from CSR in Java. We will not use an actual CA but a self-signed certificate to act as a CA certificate. Since the CSR contains the subject information where a certificate needs to be generated and signed for. The key here is to extract the subject information from the CSR and then set it as the subje...

   JAVA,CSR,SIGN CERTIFICATE     2020-10-24 07:03:17

  String.length() vs String.getBytes().length in Java

In Java, String.length() is to return the number of characters in the string, while String.getBytes().length is to return the number of bytes to represent the string with the specified encoding. By default, the encoding will be the value of system property file.encoding, the encoding name can be set manually as well by calling System.setProperty("file.encoding", "XXX"). For example, UTF-8, Cp1252. In many cases, String.length() will return the same value as String.getBytes().length, but in some ...

   Java,UTF8,String,Encoding,Sample     2015-04-01 22:22:23

  Currency list with symbols

For those who want to find out a currency code, name, symbol, numeric code and decimal numbers, below is a simple JSON structure for easy use. [{ "code": "AED", "numeric": "784", "name": "UAE Dirham", "symbol": "د.إ", "decimal": 2 }, { "code": "AFN", "numeric": "971", "name": "Afghani", "symbol": "؋", "decimal": 2 }, { "code": "ALL", "numeric": "008", "name": "Lek", "symbol": "L", "decimal": 2 }, { "code": "AMD", "numeric": "051", "name": "Arme...

   JSON,REFERENCE,NUMERIC CODE,SYMBOL,CURRENCY     2021-12-03 04:38:50

  How to make select in WinSock exceed the 64-socket limit

When doing cross-platform network programming, the only API available on Windows that corresponds to the epoll/kevent style reactor event model is select. However, it has a limitation: the number of sockets passed into select cannot exceed FD_SETSIZE, which is set to 64. Therefore, select in Java’s NIO on Windows also has the same limit. Many services ported to Windows that use the reactor model face this constraint, which often gives the impression that server programs on Windows hav...

   EXCEED,SELECT,JAVA,WINDOWS     2024-10-31 23:47:50

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